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The olfactory and trigeminal pathways are direct delivery pathways between the nose and brain. To determine the effect of direct delivery on drug distribution in the brain, two model drugs with different physical properties, antipyrine (ANP), with high membrane permeability, and ranitidine (RNT), with low membrane permeability, were selected. For ANP, direct delivery from the nose to the brain was observed only in the olfactory bulb beside the nasal cavity, with a direct transport percentage (DTP) of approximately 45 %, whereas in the frontal and occipital brains, the contribution from the systemic circulation to the brain was observed as the primary route of brain distribution. No significant variations were observed in the pharmacokinetics of ANP in the left and right brain, whereas RNT was distributed in all brain regions with a DTP of > 95 %. The closer the brain region is to the nasal cavity, the higher the DTP. Furthermore, the left brain, the same nostril site (left nostril) of administration, had a larger level of drug delivery than the right brain. These findings imply that the influence of the administered nostril site differs based on the physicochemical properties and amount of the drug., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)

Membrane permeability plays an important role in oral drug absorption. Caco-2 and Madin-Darby Canine Kidney (MDCK) cell culture systems have been widely used for assessing intestinal permeability. Since most drugs are absorbed passively, Parallel Artificial Membrane Permeability Assay (PAMPA) has gained popularity as a low-cost and high-throughput method in early drug discovery when compared to high-cost, labor intensive cell-based assays. At the National Center for Advancing Translational Sciences (NCATS), PAMPA pH 5 is employed as one of the Tier I absorption, distribution, metabolism, and elimination (ADME) assays. In this study, we have developed a quantitative structure activity relationship (QSAR) model using our ∼6500 compound PAMPA pH 5 permeability dataset. Along with ensemble decision tree-based methods such as Random Forest and eXtreme Gradient Boosting, we employed deep neural network and a graph convolutional neural network to model PAMPA pH 5 permeability. The classification models trained on a balanced training set provided accuracies ranging from 71% to 78% on the external set. Of the four classifiers, the graph convolutional neural network that directly operates on molecular graphs offered the best classification performance. Additionally, an ∼85% correlation was obtained between PAMPA pH 5 permeability and in vivo oral bioavailability in mice and rats. These results suggest that data from this assay (experimental or predicted) can be used to rank-order compounds for preclinical in vivo testing with a high degree of confidence, reducing cost and attrition as well as accelerating the drug discovery process. Additionally, experimental data for 486 compounds (PubChem AID: 1645871) and the best models have been made publicly available (https://opendata.ncats.nih.gov/adme/)., (Published by Elsevier Ltd.)

Objective: The present study was aimed at investigating the possible antiulcer activities of some natural phytochemicals Aloe perryi leaf extract (APLE) and flower extract (APFE) in addition to the date palm seed extract (DPSE) and the oily samples of DPSE in a pylorus ligation-induced ulcer model using ranitidine as a standard antiulcer drug., Background: Peptic ulcer is a prevalent gastrointestinal disorder due to hypersecretion of gastric acid. It affects four million people worldwide, and 2-10% of these ulcers are perforated and cause bleeding. This increases the risk of morbidity and mortality. So we aimed to introduce a primary study alternatively safe method for treating peptic ulcer., Materials and Methods: Forty-two Wistar Albino rats of either sex were randomly divided into seven groups (6/each). The pylorus ligation was done to induce ulcer in pretreated albino rats. The antiulcer activities of extracts were estimated at different dose levels (250 and 500 mg/kg) using ranitidine as a standard drug (50 mg/kg). Gastric volume, pH, and total and free acidity as well as ulcer index and percentage of ulcer inhibition were measured to elucidate the antiulcerogenic effects. Histological examination of gastric ulcer was also performed. Statistical analysis for the results was done where P < 0.05 was considered statistically significant., Results: Pylorus ligation for 6 h in control rats resulted in gastric ulcer which was indicated by the accumulation of gastric secretion and increased total acidity and decreased pH. The pretreatment of rats with APLE, APFE, and DPSE in addition to the oily samples of DPSE significantly inhibited the ulcers induced by pylorus ligation. These effects were attributed to significant reductions in total and free acidity, ulcer index, and gastric volume while there is a marked decrease in gastric pH (the antisecretory) as well as mucosal strengthening properties of these phytochemicals., Conclusion: These findings give these extracts the potential to be a promising tool for the management of gastric ulcer after performing further clinical and experimental studies. Our study demonstrated the promising antiulcer activity of extracts and oils in pyloric ligation-induced gastric ulcer. To the best of our knowledge, this is the first study to explore the antiulcer activity of these extracts; however, further investigations may be recommended for full details about this antiulcerogenic capacity., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2022 Naif Al-Gabri et al.)

Background: The discovery that ranitidine is contaminated with N -nitrosodimethylamine, a suspected human carcinogen, raises the hypothesis of a gastrointestinal carcinogenic effect; however, evidence remains inconclusive., Methods: We used the nationwide Danish Prescription Registry to identify a cohort of incident ranitidine users and two active comparator cohorts comprising users of other histamine-2 receptor blockers (H2RB) and users of proton pump inhibitors (PPI). All Danish adults with a first prescription of ranitidine, other H2RBs, or PPIs in 1996 through 2008 were followed virtually completely through 2018 for incidence of esophageal, stomach, liver, and pancreatic cancers. We used Cox regression with propensity-score weighting to calculate hazard ratios and 10-year cumulative risk with 95% confidence intervals., Results: We ascertained 276 newly diagnosed esophageal, 342 stomach, 133 hepatocellular, and 517 pancreatic cancers among ranitidine users during follow-up (median 14 years). In comparison with use of other H2RBs or PPIs, we found no consistent evidence of increased HRs or excess 10-year cumulative risk of any upper gastrointestinal cancer following ranitidine use. We observed no association after restriction to subjects with at least 5 or 10 prescriptions or those with 10 prescriptions and at least 10 years of follow-up., Conclusions: Our large prospective study using high-quality prescription and cancer incidence data, with two active comparator groups, provides no compelling evidence that ranitidine increases the risk of upper gastrointestinal cancers., Impact: Our results, which do not support any carcinogenic effect on esophagus, stomach, liver or pancreas, should be reassuring for millions of concerned past users of ranitidine., (©2021 American Association for Cancer Research.)

Effective Helicobacter pylori (H. pylori) eradication is a major public health concern; however, eradication failure rates with the standard triple therapy remain high. We aimed to investigate the effectiveness and tolerability of ranitidine bismuth citrate (RBC) pretreatment before standard triple therapy for H. pylori eradication. A prospective, randomized, controlled, and open-label clinical trial was conducted from June to December 2019. H. pylori eradication rate, safety, and tolerability were compared between the standard treatment group (esomeprazole, amoxicillin, and clarithromycin for 7 days) and RBC pretreatment group (RBC for 2 weeks before standard triple therapy). This trial ended earlier than estimated owing to the N-nitrosodimethylamine concerns with ranitidine. Success rates of H. pylori eradication were 80.9% and 67.3% in the RBC pretreatment (n = 47) and standard treatment (n = 52) (p = 0.126) groups, respectively. Our trial was discontinued earlier than planned; however, a statistical significance would be achieved by expansion of our data (p = 0.031) if patient enrollment numbers reached those initially planned. Adverse event rates were comparable between groups (25.5% in the pretreatment group vs. 28.8% in the standard treatment group), without serious event. Tolerability was excellent in both groups, recorded as 97.9% and 100% in the pretreatment and standard treatment groups, respectively. Compared with the standard triple regimen, RBC pretreatment for 2 weeks may achieve higher H. pylori eradication rates, with excellent safety and tolerability. However, this study necessitates further validation as it was discontinued early owing to the N-nitrosodimethylamine issues of ranitidine.

Importance: In 2019, the US Food and Drug Administration (FDA) received a citizen petition indicating that ranitidine contained the probable human carcinogen N-nitrosodimethylamine (NDMA). In addition, the petitioner proposed that ranitidine could convert to NDMA in humans; however, this was primarily based on a small clinical study that detected an increase in urinary excretion of NDMA after oral ranitidine consumption., Objective: To evaluate the 24-hour urinary excretion of NDMA after oral administration of ranitidine compared with placebo., Design, Setting, and Participants: Randomized, double-blind, placebo-controlled, crossover clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) conducted in 18 healthy participants. The study began in June 2020, and the end of participant follow-up was July 1, 2020., Interventions: Participants were randomized to 1 of 4 treatment sequences and over 4 periods received ranitidine (300 mg) and placebo (randomized order) with a noncured-meats diet and then a cured-meats diet. The cured-meats diet was designed to have higher nitrites, nitrates (nitrate-reducing bacteria can convert nitrates to nitrites), and NDMA., Main Outcome and Measure: Twenty-four-hour urinary excretion of NDMA., Results: Among 18 randomized participants (median age, 33.0 [interquartile range {IQR}, 28.3 to 42.8] years; 9 women [50%]; 7 White [39%], 11 African American [61%]; and 3 Hispanic or Latino ethnicity [17%]), 17 (94%) completed the trial. The median 24-hour NDMA urinary excretion values for ranitidine and placebo were 0.6 ng (IQR, 0 to 29.7) and 10.5 ng (IQR, 0 to 17.8), respectively, with a noncured-meats diet and 11.9 ng (IQR, 5.6 to 48.6) and 23.4 ng (IQR, 8.6 to 36.7), respectively, with a cured-meats diet. There was no statistically significant difference between ranitidine and placebo in 24-hour urinary excretion of NDMA with a noncured-meats diet (median of the paired differences, 0 [IQR, -6.9 to 0] ng; P = .54) or a cured-meats diet (median of the paired differences, -1.1 [IQR, -9.1 to 11.5] ng; P = .71). No drug-related serious adverse events were reported., Conclusions and Relevance: In this trial that included 18 healthy participants, oral ranitidine (300 mg), compared with placebo, did not significantly increase 24-hour urinary excretion of NDMA when participants consumed noncured-meats or cured-meats diets. The findings do not support that ranitidine is converted to NDMA in a general, healthy population., Trial Registration: ClinicalTrials.gov Identifier: NCT04397445.

Background: Ranitidine, a histamine 2 blocker, is the standard of care to prevent hypersensitivity reactions (HSRs) caused by paclitaxel infusion. However, the added value of ranitidine in this premedication regimen is controversial. Therefore, we compared the incidence of HSRs during paclitaxel treatment between a standard regimen including ranitidine and a regimen without ranitidine., Methods: This prospective, pre-post interventional, non-inferiority study compared the standard premedication regimen (N = 183) with dexamethasone, clemastine and ranitidine with a premedication regimen without ranitidine (N = 183). The primary outcome was the incidence of HSR grade ≥3. Non-inferiority was determined by checking whether the upper bound of the two-sided 90% confidence interval (CI) for the difference in HSR rates excluded the +6% non-inferiority margin., Results: In both the pre-intervention (with ranitidine) and post-intervention (without ranitidine) group 183 patients were included. The incidence of HSR grade ≥3 was 4.4% (N = 8) in the pre-intervention group and 1.6% (N = 3) in the post-intervention group: difference -2.7% (90% CI: -6.2 to 0.1)., Conclusions: As the upper boundary of the 90% CI does not exceed the predefined non-inferiority margin of +6%, it can be concluded that a premedication regimen without ranitidine is non-inferior to a premedication regimen with ranitidine., Clinical Trial Registration: www.trialregister.nl ; NL8173.

The high incidence of alcoholic poisoning in Indonesia is caused by the use of methanol as a surrogate ingredient of nonconforming alcohol. The product of methanol metabolism is toxic to the liver. Ranitidine has been studied as an antidote to reduce the effect of methanol toxicity. The present study aimed to assess the effect of ranitidine administration on the liver damage of Wistar rats with acute methanol intoxication. This research was an experimental study with randomized and posttest-only control group design. A total of 24 male Wistar rats divided into four groups, each consisting of six Rats. The control group (K0) served as a reference normal value. The control group (K1) was intoxicated with methanol 7 g/kg body weight (b.w.) through rat gavage tube. Treatment groups were intoxicated with methanol and 15 minutes after that, Ranitidine (30 mg/kg b.w. (P1) or 60 mg/kg b.w. (P2)) was given intraperitoneally. Ranitidine administration was proven to protect the liver tissue from damage due to methanol intoxication as was indicated from the histopathological examination. Ranitidine with dose 60 mg/kg b.w. is better in reducing the degree of liver tissue damage in acute methanol intoxication rats.

Introduction: Gastric acidity plays an important role in the protection of infants against various pathogens from the environment. The histamine-2 receptor blockers (H2-blockers) are off-labeled drugs that are frequently prescribed in preterm neonates to prevent stress ulcers. The impact of the H2-blockers on the development of the necrotizing enterocolitis (NEC) in preterm infants is still controversial, particularly in the developing world., Materials and Methods: One hundred twenty-two preterm infants were enrolled in the study. The multivariate logistic regression model was used to identify potential postnatal risk factors associated with NEC., Results: Preterm infants (n = 51) with total NEC, medical NEC, and surgical NEC had the highest rate of receiving ranitidine compared with controls (n = 71) (39.2%, 19.6%, and 47.6%, p < 0.05). Logistic regression analysis revealed that ranitidine use and nosocomial infections were significantly associated with NEC development (odds ratios 1.55 and 3.3)., Conclusions: We confirm that ranitidine administration was associated with an increased risk of NEC in preterm infants. H2-blockers use should be only administered in very strictly selected cases after careful consideration of the risk-benefit ratio.

H2 receptors' antagonists (H2RA) are widely used drugs and they are generally well-tolerated. Ranitidine hypersensitivity reactions (HR) are rarely reported. The article emphasizes the importance of recognizing ranitidine as a cause of anaphylaxis and the advantages and limits of allergological evaluation to establish a positive diagnose. We reviewed a series of published cases of ranitidine-induced hypersensitivity reactions, starting from a clinical case presentation. Moreover, we analyzed the ranitidine related adverse events in the Eudravigilance European database of adverse reactions. Most of the allergic reactions induced by ranitidine are type I HR with immediate onset after exposure, with variable clinical presentation. But in a few cases, there were also described delayed reactions, some after occupational exposure. The article underlines the importance of allergy evaluation to avoid future contact with the drug to reduce the risk of more severe reactions. The suspected reactions should be reported, allowing pharmacovigilance systems to analyse them and to establish further recommendations for clinicians.

Proton pump inhibitors (PPI) are suppressors of gastric acid secretion (SGAS) that decrease gastric nitric oxide (NO) formation from nitrite and increase the cardiovascular risk. However, H2 receptor antagonists (H2RA) are considered safer than PPIs. We challenged this notion and hypothesized that both omeprazole (PPI) and ranitidine (H2RA) attenuate the responses to oral nitrite because both drugs increase gastric pH and therefore could decrease nitrite-derived NO formation in the stomach. We examined the blood pressure responses to oral nitrite in hypertensive rats treated with omeprazole, ranitidine, or vehicle. Chemiluminensce-based assays were used to measure gastric NO formation, plasma and gastric concentrations of nitrite, nitrate, and nitrosylated species (RXNO) to clarify the mechanism involved in the effects of SGAS on the responses to oral nitrite. Both drugs increased gastric pH, impaired oral nitrite-induced hypotensive responses, gastric NO formation, and blunted the increases in circulating RXNO concentrations, but not in circulating nitrite and nitrate concentrations. These findings were reproduced in a second study using sodium acetate buffers at pH 3.5, 4.5, and 5.5 to mimic gastric pH found with vehicle, ranitidine, and omeprazole, respectively. Increasing gastric pH impaired oral nitrite-induced hypotensive responses, gastric NO formation, and blunted the increases in circulating RXNO concentrations, but not in circulating nitrite and nitrate concentrations. Our results clearly indicate that SGAS impair nitrite-induced gastric formation of NO and vasoactive RXNO in a pH-dependent manner, thus resulting in impaired responses to oral nitrite. These findings may have several clinical implications, particularly to patients with cardiovascular diseases., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Trospium chloride, a muscarinic receptor blocker, is poorly absorbed with different rates from areas in the jejunum and the cecum/ascending colon. To evaluate whether organic cation transporter (OCT) 1, OCT2 and multidrug and toxin extrusion (MATE) 1 and MATE2-K are involved in pharmacokinetics, competitions with ranitidine, a probe inhibitor of the cation transporters, were evaluated in transfected HEK293 cells. Furthermore, a drug interaction study with trospium chloride after intravenous (2 mg) and oral dosing (30 mg) plus ranitidine (300 mg) was performed in 12 healthy subjects and evaluated by noncompartmental analysis and population pharmacokinetic modeling. Ranitidine inhibited OCT1, OCT2, MATE1, and MATE2-K with half maximal inhibitory concentration values of 186 ± 25 µM, 482 ± 105 µM, 134 ± 37 µM, and 35 ± 11 µM, respectively. In contrast to our hypothesis, coadministration of ranitidine did not significantly decrease oral absorption of trospium. Instead, renal clearance was lowered by ∼15% (530 ± 99 vs 460 ± 120 mL/min; P < .05). It is possible that ranitidine was not available in competitive concentrations at the major colonic absorption site, as the inhibitor is absorbed in the small intestine and undergoes degradation by microbiota. The renal effects apparently result from inhibition of MATE1 and/or MATE2-K by ranitidine as predicted by in vitro to in vivo extrapolation. However, all pharmacokinetic changes were not of clinical relevance for the drug with highly variable pharmacokinetics. Intravenous trospium significantly lowered mean absorption time and relative bioavailability of ranitidine, which was most likely caused by muscarinic receptor blocking effects on intestinal motility and water turnover., (© 2019 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

The purpose of this study was to develop a novel gastroretentive drug delivery system with immediate buoyancy and high wet strength. The proposed bilayer tablet was composed of a drug layer and a highly porous and swellable gastroretentive (GR) layer. The highly porous GR layer was prepared by sublimating the volatile materials after compaction with swellable polymers. This pore-forming process decreased the density of the GR layer and enabled the tablet to float immediately on the dissolution media. The GR layer formulation was optimized by comparing the swelling, erosion, and mechanical properties of candidate swellable polymers. The release rates were conveniently controlled by changing the polymer content in the drug layer, while the swelling and floating properties were provided by the GR layer. The application of percolation theory revealed that the polymer content above the estimated threshold was required for a reliable drug release profile. In vivo study in fed beagle dogs confirmed the enhanced gastric retention time of the tablets compared to that of conventional single layer tablets. Taken together, our data suggest that the proposed system can be a promising platform technology with superior GR properties and a convenient formulation process., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Several studies have shown that Pylera ® (three-in-one capsules containing 140 mg bismuth potassium subcitrate, 125 metronidazole, and tetracycline 125 mg) in association with omeprazole or esomeprazole is a good option in the treatment of Helicobacter pylori infection. In particular, the adjunction of a PPI to Pylera ® may be useful to overcome metronidazole resistance. However, omeprazole and its derivatives can promote greater bismuth absorption and enhance its toxicity. The H2 receptor antagonist (H2RA) ranitidine seems to induce less bismuth absorption and as a consequence less systemic toxicity., Aim: To evaluate whether Pylera ® in combination with esomeprazole or with ranitidine is equally effective in the treatment of H. pylori infection., Material and Methods: Two separate groups of patients were treated simultaneously. One group was treated with Pylera ® three capsules qid plus esomeprazole 40 mg bid for 10 days (group A), and the other group was treated with Pylera ® three capsules qid plus ranitidine 300 mg bid for 10 days (group B). H. pylori eradication was defined as a negative result in 13 C urea breath test performed at least 8 weeks after the end of treatment with a delta-over-baseline value less than 5., Results: Thirty-two patients were recruited for group A and thirty-three patients in group B. Eradication rates were 93.7% (30/32) and 90.9% (30/33), respectively, at intention-to-treat analysis, and 96.6% (29/30) and 93.3% (28/30), respectively, at per-protocol analysis. Adverse events occurred in 26 patients and led to the suspension of treatment in one patient in group A and in one patient in group B., Conclusion: The results showed that Pylera® plus a PPI or ranitidine were equally effective in the population studied. The high cure rates of bismuth triple therapy (without an antisecretory drug) and the lack of susceptibility testing make it impossible to exclude the possibility that the results would have been similar if neither the PPI nor the ranitidine were given., (© 2019 John Wiley & Sons Ltd.)

This study was aimed at investigating morphological and biochemical efficacies of antioxidants on indomethacin-induced small intestinal damage in rats. Group I: control animals (negative control) given only placebo, Group II: (positive control) are animals orally given combination of antioxidants [vitamin C (Vit C), vitamin E (Vit E), β-carotene and sodium selenite (Se)] daily for 3 days, Group III: Rats were given only indomethacin, Group IV: animals were given of antioxidants combination for 3 days, last dose was given 2 hr before the administration of indomethacin. Group V: Animals receiving ranitidine for 3 days (second positive control). Group VI: Animals received ranitidine for 3 days, last dose was given 2 hr before to indomethacin administration. Indomethacin caused degenerative morphological and biochemical changes, which were reversed on antioxidants administration. As a result, we propose that antioxidants combination would be therapeutically beneficial for treating indomethacin-induced lesions of small intestine. PRACTICAL APPLICATIONS: Indomethacin is a widely preferred nonsteroidal anti-inflammatory drug (NSAID) but its side effects on gastrointestinal system are well known. Indomethacin also causes production of reactive oxygen species. Antioxidants and selenium has protective effects. According to the results of this study, antioxidants and selenium can be used as a food supplement for preventing NSAID-induced side effects and toxicity., (© 2019 Wiley Periodicals, Inc.)

Objective: Oral gastroretentive system is one of the site-specific drug delivery system, which is designed to be retained in upper GIT for a prolonged time. Ranitidine hydrochloride (RHCl), which is used frequently in treatment of peptic ulcer, is a suitable candidate for gastroretentive delivery systems. Dependently, floating oil-entrapped alginate beads of RHCl were developed and evaluated as an approach to site-specific delivery avoiding colonic degradation and enhancing both bioavailability and the proposed local effect., Methods: Different formulations of floating beads were suggested and randomized using 2 4 full factorial design. Optimized formulation was subjected for in vivo studies to measure the oral bioavailability and the healing effect of induced peptic ulcers., Results: Beads size ranged from 1.32 to 2.3 mm. All beads revealed excellent floating capabilities. Optimum formulation (F12) has entrapment efficiency of 70%, drug loading of 7% and 71% RHCl released after 6 h. SEM of F12 shows a grossly spherical structure with presence of oil droplets distributed throughout structure. AUC obtained from F12 was nonsignificantly higher than that of a commercial tablet. Signs of ulcer healing appeared clearly with F12 through appearance of granulation tissue, collagen fibers and newly formed blood vessels. Healing rate and extent obtained with a commercial tablet were less than F12. Quantitative analysis confirmed histopathological findings., Conclusion: Floating oil-entrapped beads are a promising approach for RHCl delivery to remain in stomach for a longer time ensuring site-specific delivery and consequently, enhancing local healing effect of peptic ulcers.

Objective. We evaluated the histamine's role in regulating the iris vasomotricity in rats, using as a research tool topical olopatadine, a selective H1 blocker, which is indicated for the treatment of allergic conjunctivitis and ranitidine, a selective H2 blocker mainly used for the treatment of peptic ulcer disease. Methods. Two groups of six Wistar rats anesthetized with ketamine 200 mg/kg body weight were used. They received distilled water in conjunctival instillations, initially and after 5 minutes, olopatadine 2.5 mmol/ l for the first group, respectively ranitidine 2.5 mmol/ l for the second group. The changes of the iris arteriolar and venular diameters were recorded. Results. Both olopatadine and ranitidine produced statistically significant iridal arteriolar vasoconstriction and ranitidine determined statistically significant venuloconstriction, while distilled water did not produce any statistically significant effect. Conclusions. There is a vasodilator histaminergic tone exerted through the histaminergic H1 and H2 receptors in the iris arterioles and, respectively, through the H2 receptors in the iridal venules. Olopatadine, a topical H1 antagonist used in the treatment of ocular allergies, may interfere with the humoral regulation of the iris arteriolar tone. Ranitidine, an H2 antagonist, decreased the diameter of the iris arterioles and venules, when administered topically in rats.

Background: Ocrelizumab is a monoclonal antibody directed against CD20+ B cells that is approved for MS. The most common side effect is infusion-associated reactions (IARs). This study examines whether a modified premedication protocol reduces incidence of IARs and further examines predictors of IARs., Methods: Patients took cetirizine 10 mg, ranitidine 75 mg, and increased hydration the night before the ocrelizumab infusion. This regimen was repeated the next day prior to arrival. Just prior to the infusion, patients were pretreated with IV diphenhydramine 50 mg, IV methylprednisolone 125 mg, and oral acetaminophen 650 mg. Rates of IARs with this modified protocol were compared to patients who had received only pretreatment medications., Results: 207 patients received ocrelizumab. With the modified premedication protocol, we found significant decreased odds of IARs (OR 0.40, p = 0.024, 95% CI (0.18, 0.88). Among the baseline characteristics, there was a significant reduction of IARs with increasing age (OR 0.94, p = 0.001) and male sex (OR 0.34, p = 0.034). Body mass index (BMI) increased the odds of IARs (OR 1.07, p = 0.029). Race and smoking status did not affect IARs., Conclusion: The modified premedication protocol described herein significantly decreases rates of IARs by 60% and suggests that the additional premedication regimen is beneficial. Age and male sex are protective for IARs while BMI is a risk factor for IARs., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Quince (Cydonia oblonga Mill) is a popular medicinal herb in different traditional medicines. Concentrated quince fruit extract, also known as quince sauce (QS), is traditionally used for the treatment of a variety of gastrointestinal disorders. The aim of this study was to compare the efficacy of QS versus ranitidine on gastroesophageal reflux disease (GERD) in pregnant women. We compared the efficacy of 4 weeks of ranitidine (150 mg, twice daily) with the efficacy of QS (10 mg, after meals) on 137 pregnant women with GERD. Their General Symptom Score (GSS) and Major Symptom Score (MSS) were compared at the baseline, 2 weeks and 4 weeks after intervention. After 2 weeks of the study, the mean GSS score of the QS group was significantly lower compared with the ranitidine group (p = .036). Although, the GSS value at the end of the study had no difference between groups (p = .074). However, the MSS of the different symptoms of the two groups at 2 weeks and 4 weeks had no significant differences. It seems that the efficacy of QS for the management of pregnancy-related GERD is similar to ranitidine. Impact statement What is already known on this subject? Quince is a traditional gastric tonic, an appetiser, and a remedy for nausea/vomiting and epigastric pain. Also, there are several previous positive experiences about quince products for GERD treatment. What do the results of this study add? It seems that the efficacy of QS for the management of pregnancy-related GERD is similar to ranitidine. What are the implications of these findings for clinical practice and/or further research? QS can be suggested as an alternative medicine for pregnant patients with GERD.

Objectives: to describe the use of proton pump inhibitors (PPI) and ranitidine in the general population living in the area of the Healthcare Authority and University of Udine (Friuli Venezia Giulia, Northeastern Italy) and to evaluate whether there are any cases of co-prescription of medications in those classes., Design: analysis of health-related administrative databases (list of potential healthcare beneficiaries, prescriptions of medications, exemption from medical charges because of chronic conditions, list of general practitioners)., Setting and Participants: population of the Italian area of the Healthcare Authority and University of Udine (approximately 250,000 inhabitants) ≥1 year of age as of January 1st, 2016., Main Outcome Measures: prevalence of PPI or H2RA use (>1 prescription in 2016), overall and stratified by drug, age class and sex; duration of the theoretical period covered by prescriptions; prevalence of co-prescriptions; association of co-prescriptions and clinical and demographic characteristics of patients (odds ratio and 95% confidence intervals)., Results: in 2016, 162 persons per 1,000 used those medications; in particular, 158/1,000 used PPIs. Prevalence of use increased with age, as did the median treatment duration with PPIs. Co-prescription of two medications of the same class were observed in 0.43% of antacid users. The likelihood of receiving co-prescriptions was higher among non-elderly subjects, long-term PPI users, and those with chronical diseases, such asthma., Conclusion: in the considered Italian area, PPIs and ranitidine were frequently used, although less than in the rest of Italy. We observed occasionally non-recommended practices, such as the co-prescription of different medications of the same class or with the same indications.

The anaphylactoid reaction described follows cessation of ranitidine in a 19-year-old female with the disease cluster: mast cell activation syndrome, hypermobile Ehlers-Danlos syndrome and postural tachycardia syndrome. Anaphylaxis can give wide-ranging symptoms from rhinorrhoea and urticaria to tachycardia and system-wide, life-threatening, anaphylactic shock. Individuals with a disorder of mast cell activation can experience many such symptoms. H 2 receptor antagonists, such as ranitidine, are commonly prescribed in this population. A mechanism for the reaction is proposed in the context of ranitidine, as an inverse agonist, causing upregulation of H 2 histamine receptors and raised histamine levels due to enzyme induction. This effect, following extended and/or high antihistamine dosing, may have implications for other individuals with a disorder of mast cell activation, such as mastocytosis or mast cell activation syndrome. There are potential policy and patient guidance implications for primary and secondary care with respect to cessation of H 2 antagonists., (© 2018 The British Pharmacological Society.)

Aim: Adequacy of enteral nutrition (EN) alone as stress ulcer prophylaxis (SUP) is controversial. The aim of this study was to compare efficacy of EN alone and ranitidine plus EN as SUP., Method: Critically ill adults with indications to receive SUP were randomized to ranitidine 50 mg IV every 8 h plus EN (SUP) or EN alone (non-SUP) group for 7 days. Besides, endoscopy was performed at the time of recruitment and on day 7., Results: During the study period, only one patient in each group of SUP and non-SUP experienced gastrointestinal bleeding. At the time of recruitment, gastric erosion and erythema were the most endoscopic findings in the SUP and non-SUP groups. These findings did not significantly change at the end of the study (p = 0.21)., Conclusion: EN was at least effective as ranitidine plus EN as SUP.

The aim of this retrospective cohort study was to investigate the incidence of delayed methotrexate elimination in patients treated with high-dose methotrexate (≥1 g/m 2 ) for haematological malignancy and to identify the impact of interacting drugs, especially proton-pump inhibitors (PPIs) and ranitidine. All patients treated with high-dose methotrexate over a 6 year period in the haematology department of the Lyon Sud University Hospital (Hospices Civils de Lyon, France) were included. Potential risk factors for delayed methotrexate elimination were tested in a generalized linear model by univariate analysis: patient age, gender, methotrexate dose, administration of PPI or ranitidine, and concomitant nephrotoxic drugs. A total of 412 cycles of methotrexate were administered to 179 patients. Proton-pump inhibitors were co-administered with methotrexate in 127 cycles and ranitidine in 192 cycles. Ninety-three cycles included no antacid drugs. A total of 918 plasma methotrexate assays were performed. Methotrexate concentrations were checked at 24 hours in 92% of cycles. Delayed methotrexate elimination was observed in 20.9% of cycles. A total of 63 cycles with delayed methotrexate elimination were only identified on plasma methotrexate measures at 72 hours: ie, plasma methotrexate was in the normal range at 24 and 48 hour post injection. Use of PPI/ranitidine or no antacid drugs did not increase risk of delayed elimination, with respectively delayed methotrexate elimination in 20.5%, 21.9%, and 19.4% of cycles (P = .89). Impaired baseline creatinine clearance showed significant association in univariate analysis. Fifteen patients showed grade 1 acute kidney injury, 1 grade 2, 2 grade 3, and none grade 4. For half of these cases, delayed methotrexate elimination was observed and the 2 grade 3 events appeared in patients treated with PPIs. This retrospective study suggests that there is no association between concomitant use of proton-pump inhibitors (pantoprazole and esomeprazole) or ranitidine and delayed methotrexate elimination., (Copyright © 2017 John Wiley & Sons, Ltd.)

The aim of this study was to prepare and evaluate calcium-free sustained release drug delivery systems, based on the in-situ gelation of oral suspensions containing chitosan, sodium alginate and Ranitidine as drug model. The combined effects of polymer concentrations and their interactions on the rheological characteristics of both gels and suspensions and, on the kinetics of drug release were evaluated by using a central composite face-centered design. Rheological analysis showed that suspensions were potentially stable, with a viscosity increased by 1000 times compared to that of water. In addition, the obtained gels were consistent; their storage modulus could reach values close to 50 kPa when alginate concentration was greater than 7.5 g/100 mL and chitosan was fixed to 0.5 g/100 mL. In these conditions gels should have a higher gastric residence time, in comparison to the standard gastric emptying time (∼2 h). Evaluation of the in-vitro release kinetics of Ranitidine showed that the association of the lowest concentration of chitosan (0.5 g/100 mL) with higher alginate concentrations generates sustained release kinetics profiles. The time corresponding to 63% of release was found close to 1.5 h, in which case the process is governed by Fickian diffusion. Finally, calcium-free alginate-chitosan based on the in-situ gelation of suspensions is advantageous as a drug delivery system for sustained-release.

Background: Accidental drug overdose is a common problem in young children. We examined the influence of formulation and dose in enquiries for different gastro-oesophageal reflux disease treatments in children under 5 years to the UK's National Poisons Information Service., Methods: Overdose characteristics with ranitidine, omeprazole or domperidone were compared with those of metoclopramide and the H-1 antagonist chlorphenamine, for the period 1 July 2007 to 30 June 2015., Results: There were a total of 1092 ranitidine, 618 domperidone and 1193 omeprazole cases; 669, 281 and 424, respectively, were single agent enquiries; of these 77% (517) of ranitidine, 52% (145) domperidone and 32% (135) omeprazole cases occurred in children <5 years. In comparison, 17% (34/424) of metoclopramide and 53% (533/1013) of chlorphenamine were <5 years; 79% (410/517) of ranitidine overdose enquiries in children <5 years were under 6 months of age, higher than domperidone (68/145, 47%; p < 0.05), omeprazole (8/135, 6%), chlorphenamine (13/553, 2%) or metoclopramide (1/34, 3%) (all p < 0.01). In children aged <6 months, 101 were 10-fold overdoses, 86 with ranitidine., Conclusions: Tenfold overdoses in children (<5 years) were a feature of ranitidine enquiries, likely due to the high concentration of the syrup. This has relevance to other liquid formulations used for non-licenced indications in young children. Such therapeutic errors cause significant carer anxiety and healthcare utilization. Assistance is needed from manufacturers and legislators in modifying formulation so that drugs can be safely used in young children. Education of prescribers and carers is also needed to reduce the incidence of such errors that cause significant carer anxiety and healthcare utilization.

Competing Interests: None

Background: Gastroparesis and GERD occur concomitantly in 40 percent of the cases. Prokinetic drugs and acid blockers are employed as the main treatment modality. Ranitidine is an acid blocker with additional prokinetic activity and Itopride is a known prokinetic drug. This study was designed to observe the synergistic potentiating prokinetic effect of Ranitidine on itopride on isolated duodenum of rabbits., Methods: Ranitidine (10-5-10-3) and itopride (10-6-10-5) were added in increasing concentrations to isolated duodenum of rabbits and contractions were recorded on PowerLab Data acquisition unit AHK/214. Cumulative dose response curves were constructed. The potentiating prokinetic effect of Ranitidine on itopride was seen by using a fixed dose of ranitidine and cumulatively enhancing doses of itopride on iWorx., Results: Ranitidine and itopride produced a dose dependent reversible contraction of the isolated tissue of rabbits with ranitidine showing a max response of 0.124mV and itopride showing a maximum response of 0.131mV. Ranitidine was able to potentiate the prokinetic effect of itopride at low doses but at high dose the effect began to wane off., Conclusions: Ranitidine and itopride produce a statistically significant synergistic potentiating prokinetic effect at low doses in vitro.

Objectives/hypothesis: Empiric proton pump inhibitor (PPI) trials for laryngopharyngeal reflux (LPR) are common. A majority of the patients respond to acid suppression. This work intends to evaluate once-daily, 40 mg omeprazole and once-nightly, 300 mg ranitidine (QD/QHS) dosing as an alternative regimen, and use this study's cohort to evaluate empiric regimens prescribed for LPR as compared to up-front testing with pH impedance multichannel intraluminal impedance (MII) with dual pH probes and high-resolution manometry (HRM) for potential cost minimization., Study Design: Retrospective cohort review and cost minimization study., Methods: A chart review identified patients diagnosed with LPR. All subjects were treated sequentially and outcomes recorded. Initial QD/QHS dosing increased after 3 months to BID if no improvement and ultimately prescribed MII and HRM if they failed BID dosing. Decision tree diagrams were constructed to determine costs of two empiric regimens and up-front MII and HRM., Results: Ninety-seven subjects met the criteria. Responders and nonresponders to empiric therapy were identified. Seventy-two subjects (74%) responded. Forty-eight (67% of responders and 49% of all) improved with QD/QHS dosing. Forty-nine (51%) subjects escalated to BID dosing. Twenty-four subjects (33% of responders and 25% of all) improved on BID therapy. Twenty-five subjects (26%) did not respond to acid suppression. Average weighted cost was $1,897.00 per patient for up-front testing, $3,033.00 for initial BID, and $3,366.00 for initial QD/QHS., Conclusions: An alternate QD/QHS regimen improved the majority who presented with presumed LPR. Cost estimates demonstrate that the QD/QHS regimen was more expensive than the initial BID high-dose PPI for 6 months. Overall per-patient cost appears less with up-front MII and HRM., Level of Evidence: 4. Laryngoscope, 127:S1-S13, 2017., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

This open-label, randomized, phase 1 crossover study investigated the effect of elevated gastric pH level (>5) on the relative bioavailability and pharmacokinetic profile of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib. Healthy male volunteers (n = 26) were randomized to gefitinib 250 mg (fasted), either alone on day 1 (unmodified gastric pH) or 1 hour following the second of 2 oral doses of the H 2 -receptor antagonist ranitidine 450 mg (elevated gastric pH). After a 3-week washout period, volunteers crossed to the other treatment. The geometric least-squares (GLS) mean AUC 0-∞ and C max for gefitinib were reduced by 47% and 71%, respectively, under conditions of sustained elevated gastric pH; for both parameters, the 90%CI for the ratio of the GLS means lay below the prespecified lower limit. Median t max was delayed from 5 to 6 hours. Mean t 1/2 was similar under both gastric pH conditions. No serious adverse events were reported. The bioavailability of a single oral gefitinib 250-mg dose was reduced by approximately 50% when gefitinib was administered under conditions of sustained elevated gastric pH., (© 2017, The American College of Clinical Pharmacology.)

Delayed gastric emptying in the presence or absence of mechanical bowel obstruction can cause distressing symptoms in palliative care patients. We present two patients, both with vomiting due to delayed gastric emptying and gastric outlet obstruction secondary to pancreatic cancer, treated with subcutaneous ranitidine resulting in a symptomatic response. We hypothesise that ranitidine is a useful adjunct to standard treatment with prokinetic agents or octreotide in such patients and potentially those with proximal mechanical bowel obstruction from other malignancies with associated delayed gastric emptying., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: High-output enterocutaneous fistula or enterostomies can cause intestinal failure. There is a wide variety of options in medical management of patients with high output., Aim: To systematically review the literature on available pharmacotherapy to reduce output and to propose an algorithm for standard of care., Methods: Relevant databases were systematically reviewed to identify studies on pharmacotherapy for reduction in (high-) output enterostomies or fistula. Randomised controlled trials and within subjects controlled prospective trials were included. An algorithm for standard of care was generated based on the outcomes of the systematic review., Results: Two studies on proton pump inhibitors, six on anti-motility agents, three on histamine receptor antagonists, one on an α2- receptor agonist and eight on somatostatin (analogues) were included. One study examined a proton pump inhibitor and a histamine receptor antagonist within the same patients. Overall, we found evidence for the following medical therapies to be effective: omeprazole, loperamide and codeine, ranitidine and cimetidine. On the basis of these outcomes and clinical experience, we proposed an algorithm for standard of care which consists of high-dose proton pump inhibitors combined with high-dose loperamide as the first step followed by addition of codeine in case of insufficient output reduction. So far, there is insufficient evidence for the standard use of somatostatin (analogues)., Conclusions: The available evidence on the efficacy of medication to reduce enterostomy or enterocutaneous fistula output is hampered by low quality studies. We propose an algorithm for standard of care output reduction in these patients., (© 2017 John Wiley & Sons Ltd.)

To evaluated the role of thymoquinone (TQ) on stress induced ulceration progress in rats subjected to water immersion restraint as a stress (WRS) condition model. Wistar albino rats were divided into different groups; the animals were subjected to WRS. TQ (10 mg/kg) alone and TQ with ranitidine (20 mg/kg) were administered per orally as pre treatment for 7 days. On 8 th day the animals were sacrificed, gastric juice, pH, acid secretion, acid output, ulcer index and markers of oxidative stress and histopathology were determined. Volume of gastric juice, acid secretion was increased, while pH decreased in WRS animals. TQ pre-treated group showed reduction in the above parameters. The combination group showed more significant results than TQ and ranitidine alone on the above parameters. TQ decreased the ulcer index (UI), again combination group showed more significant decreased in UI. Oxidative stress markers were reduced and antioxidant enzymes were augmented. Gastric mucosa was protected as demonstrated by histological slides. The present study is one of its kinds to demonstrate anti ulcer effect of TQ against the water immersion restraint method of stress ulceration. Thus, TQ has the potential to be the promising drug for stress induced gastric ulcers., Competing Interests: Conflict of Interest: All authors declare that they have no conflict of interest in this research., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: The inhibition of gastric acid secretion with ranitidine is frequently prescribed off-label to newborns admitted to neonatal intensive care units (NICU). Some studies show that the use of inhibitors of gastric acid secretion (IGAS) may predispose to infections and necrotising enterocolitis (NEC), but there are few data to confirm this association. This study aimed to compare the rates of neonatal infections and NEC among preterm infants (<37 weeks gestation) hospitalised in a NICU exposed or not to treatment with ranitidine., Methods: A retrospective cohort study was conducted with all consecutive preterm newborns admitted to a NICU between August-2014 and October-2015. The rates of infection, NEC, and death of newborns exposed or not to ranitidine were recorded., Results: A total of 300 newborns were enrolled, of which 115 had received ranitidine and 185 had not. The two groups were similar with regard to the main demographic and clinical characteristics. Forty-eight (41.7%) of the 115 infants exposed to ranitidine and 49 (26.5%) of the 185 infants not exposed were infected (RR = 1.6, 95%CI 1.1-2.2, p = 0.006). The late onset (>48 h) blood culture positive infection rate was higher in the group exposed to ranitidine than in the untreated group (13.0% vs. 3.8%, p = 0.001). There was no significant association between the use of ranitidine and NEC (Bell stage >II) (p = 0.36). The mortality rate risk was 4-fold higher in infants receiving ranitidine (16.5% vs. 8.6%, p < 0.001)., Conclusion: Ranitidine use in neonates was associated with an increased risk of infections and mortality, but not with NEC.

The purpose of our investigation was to develop and optimize the drug entrapment efficiency and bioadhesion properties of mucoadhesive chitosan microspheres containing ranitidine HCl prepared by an ionotropic gelation method as a gastroretentive delivery system; thus, we improved their protective and therapeutic gastric effects in an ulcer model. A 3 × 2 2 full factorial design was adopted to study the effect of three different factors, i.e., the type of polymer at three levels (chitosan, chitosan/hydroxypropylmethylcellulose, and chitosan/methylcellulose), the type of solvent at two levels (acetic acid and lactic acid), and the type of chitosan at two levels (low molecular weight (LMW) and high molecular weight (HMW)). The studied responses were particle size, swelling index, drug entrapment efficiency, bioadhesion (as determined by wash-off and rinsing tests), and T 80% of drug release. Studies of the in vivo mucoadhesion and in vivo protective and healing effects of the optimized formula against gastric ulcers were carried out using albino rats (with induced gastric ulceration) and were compared to the effects of free ranitidine powder. A pharmacokinetic study in rabbits showed a significant, 2.1-fold increase in theAUC 0-24 of the ranitidine microspheres compared to free ranitidine after oral administration. The optimized formula showed higher drug entrapment efficiency and mucoadhesion properties and had more protective and healing effects on induced gastric ulcers in rats than ranitidine powder. In conclusion, the prolonged gastrointestinal residence time and the stability of the mucoadhesive microspheres of ranitidine as well as the synergistic healing effect of chitosan could contribute to increasing the potential of its anti-gastric ulcer activity.

Hypomagnesemia is a common but often overlooked problem in hospitalized patients. Unrecognized hypomagnesemia can cause serious complications. The association of hypokalemia and hypocalcemia is strongly evocative of a magnesium deficiency. Research into the causes of hypomagnesemia is imperative, as it will definitely change the approach, treatment and prognosis. We report the case of a 65-year-old man with chronic hypocalcemia and hypokalemia associated with cerebellar syndrome, a solitary seizure and cerebellar hyperintensities on magnetic resonance imaging. After the detection and treatment of hypomagnesemia with oral supplements of magnesium and the replacement of pantoprazole with ranitidine, we observed immediate relief of the symptoms. In conclusion, in clinical practice, magnesium depletion should be investigated in elderly patients with hypocalcemia treated with proton pump inhibitors for many years, in particular in the presence of neurological disorders.

The use of anti-ulcer medications, such as cimetidine, ranitidine, and omeprazole, is common in performance horses. The use of these drugs is regulated in performance horses, and as such a withdrawal time is necessary prior to competition to avoid a medication violation. To the authors' knowledge, there are no reports in the literature describing repeated oral administrations of these drugs in the horse to determine a regulatory threshold and related withdrawal time recommendations. Therefore, the objective of the current study was to describe the disposition and elimination pharmacokinetics of these anti-ulcer medications following oral administration to provide data upon which appropriate regulatory recommendations can be established. Nine exercised Thoroughbred horses were administered 20 mg/kg BID of cimetidine or 8 mg/kg BID of ranitidine, both for seven doses or 2.28 g of omeprazole SID for four doses. Blood samples were collected, serum drug concentrations were determined, and elimination pharmacokinetic parameters were calculated. The serum elimination half-life was 7.05 ± 1.02, 7.43 ± 0.851 and 3.94 ± 1.04 h for cimetidine, ranitidine, and omeprazole, respectively. Serum cimetidine and ranitidine concentrations were above the LOQ and omeprazole and omeprazole sulfide below the LOQ in all horses studied upon termination of sample collection., (© 2016 John Wiley & Sons Ltd.)

Children often require transfer to pediatric hospital emergency departments (EDs) after evaluation in community hospital EDs. Such transfers are regulated by the federal Emergency Medical Treatment and Labor Act. Unusual circumstances, such as logistical errors in the physical transfer of the patient, may increase Emergency Medical Treatment and Labor Act-related liability risks for hospitals and ED physicians.

Males and females respond differently to drugs: indeed, sex plays a crucial role in determining drug pharmacokinetics and pharmacodynamics. Excipients have also been shown to enhance the biovailability of drugs differently in men and women. The aim of this work was to investigate whether rodents are a good model in which to study sex-specific effects of polyethylene glycol 400 (PEG 400) on the bioavailability of ranitidine. Ranitidine (50mg/kg) was dissolved in water with different amounts of PEG 400-0 (control), 13, 26, 51, 77, 103, and 154mg/kg; these solutions were dosed orally by gavage to male and female Wistar rats. Blood samples were withdrawn over 480min and assayed via HPLC-UV. Individual ranitidine plasma profiles were constructed for each rat, and standard pharmacokinetic parameters were determined. In the male rats, the change in the area under the plasma ranitidine curve (AUC0-480) compared to the control group, was +18%; +49% (p<0.05); +37% (p<0.05); +31% (p<0.05); +8% and -22% (p<0.05) for PEG 400 doses of 13; 26; 51; 77; 103; and 154mg/kg respectively. On the other hand, females showed no statistically significant difference between the groups. In conclusion, low doses of PEG 400 enhanced the bioavailability of ranitidine in male, but not female, rats. These findings are in agreement with previously published human data, therefore confirming the validity of the rodent model, and highlight the unusual and clinically significant phenomenon that an excipient can influence drug bioavailability in one gender and not the other., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The H2-receptor antagonist, ranitidine, is among the most widely used pharmaceuticals to treat gastroesophageal reflux disease and peptic ulcers. While previous studies have demonstrated that amines can form N-nitrosamines when exposed to nitrite at stomach-relevant pH, N-nitrosamine formation from ranitidine, an amine-based pharmaceutical, has not been demonstrated under these conditions. In this work, we confirmed the production of N-nitrosodimethylamine (NDMA), a potent carcinogen, by nitrosation of ranitidine under stomach-relevant pH conditions in vitro We also evaluated the urinary NDMA excretion attributable to ingestion of clinically used ranitidine doses. Urine samples collected from five female and five male, healthy adult volunteers over 24-h periods before and after consumption of 150mg ranitidine were analyzed for residual ranitidine, ranitidine metabolites, NDMA, total N-nitrosamines and dimethylamine. Following ranitidine intake, the urinary NDMA excreted over 24h increased 400-folds from 110 to 47 600ng, while total N-nitrosamines increased 5-folds. NDMA excretion rates after ranitidine intake equaled or exceeded those observed previously in patients with schistosomiasis, a disease wherein N-nitrosamines are implicated as the etiological agents for bladder cancer. Due to metabolism within the body, urinary NDMA measurements represent a lower-bound estimate of systemic NDMA exposure. Our results suggest a need to evaluate the risks attributable to NDMA associated with chronic consumption of ranitidine, and to identify alternative treatments that minimize exposure to N-nitrosamines., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Histamine is a potent vasodilator that has been found to increase during exercise. We tested the hypothesis that histamine would attenuate blood pressure (BP), cardiac output (CO), and vascular resistance responses to short-term, submaximal dynamic exercise during H2 receptor blockade. Fourteen healthy men (20-29 years of age) were studied. Systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP and heart rate (HR) were assessed at rest and during the last minute of 10 min of submaximal cycling exercise (60% of peak oxygen consumption) in the absence and presence of histamine H2 receptor blockade (ranitidine, 300 mg). Stroke volume (SV) (impedance cardiography) and plasma norepinephrine (NE) were measured, and CO, rate × pressure product (RPP), and total peripheral resistance (TPR) were calculated. Plasma levels of histamine were also measured. H2 blockade had no effects on any variables at rest. During exercise, SBP (184 ± 3 mm Hg vs. 166 ± 2 mm Hg), MAP (121 ± 2 mm Hg vs. 112 ± 5 mm Hg), and RPP (25.9 ± 0.8 × 10(3) mm Hg·beats/min vs. 23.5 ± 0.8 × 10(3) mm Hg/beats·min) were greater during blocked conditions (P < 0.05), and an interaction was observed for TPR. SV, DBP, HR, and NE levels were unaffected by blockade. Plasma histamine increased from 1.83 ± 0.14 ng/mL at rest to 2.33 ± 0.23 ng/mL during exercise (P < 0.05) and was not affected by H2 blockade (1.56 ± 0.23 ng/mL vs. 1.70 ± 0.24 ng/mL). These findings suggest that, during submaximal exercise, histamine attenuates BP, vascular resistance, and the work of the heart via activation of H2 receptors and that these effects occurred primarily in the vasculature and not in the myocardium.

Dual antiplatelet therapy (DAPT) with clopidogrel and aspirin is used for the prevention of cardiovascular events following percutaneous coronary intervention (PCI). These agents increase the risk of gastrointestinal bleeding. To prevent these events, proton pump inhibitors (PPI) are routinely prescribed. It has been reported that with the exception of pantoprazole and dexlanzoprazole, PPIs can impede conversion of clopidogrel by cytochrome P450 2C19 (CYP2C19) to its active metabolite, a critical step required for clopidogrel efficacy. Changes in CYP2C19 enzyme activity (phenotype) and its correlation with platelet reactivity following PPI therapy has not yet been fully described. In this study we attempted to determine if the [ (13)C]-pantoprazole breath test (Ptz-BT) can evaluate changes in CYP2C19 enzyme activity (phenoconversion) following the administration of PPI in coronary artery disease (CAD) patients treated with DAPT after PCI. Thirty (30) days after successful PCI with stent placement, 59 patients enrolled in the Evaluation of the Influence of Statins and Proton Pump Inhibitors on Clopidogrel Antiplatelet Effects (SPICE) trial (ClinicalTrials.gov Identifier: NCT00930670) were recruited to participate in this sub study. Patients were randomized to one of 4 antacid therapies (omeprazole, esomeprazole. pantoprazole or ranitidine). Subjects were administered the Ptz-BT and platelet function was evaluated by vasodilator-stimulated phosphoprotein (VASP) phosphorylation and light transmittance aggregometry before and 30 d after treatment with antacid therapy. Patients randomized to esomeprazole and omeprazole had greater high on-treatment platelet reactivity and lowering of CYP2C19 enzyme activity at Day 60 after 30 d of PPI therapy. Patients randomized to ranitidine and pantoprazole did not show any changes in platelet activity or CYP 2C19 enzyme activity. In patients treated with esomeprazole and omeprazole, changes in CYP2C19 enzyme activity (phenoconversion) correlated well with changes in platelet reactivity. Co-administration of omeprazole or esomeprazole in patients treated with clopidogrel results in lower CYP2C19 enzyme activity and increased platelet reactivity as measured by VASP phosphorylation test while patients given pantoprazole or ranitidine did not show any significant changes in CYP2C19 enzyme activity and platelet reactivity.

Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, the in vivo anti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-) κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive components in vivo, thus contributing to the immune regulatory role of fruits and herbs.

Carbopol (CP) is a biocompatible bioadhesive polymer used as a matrix for gastroretentive (GR) tablets, however, its rapid hydration shortens its bioadhesion and floating when incorporated in effervescent formulae. The interpolymer complexation of CP with polyvinylpyrrolidone (PVP) significantly reduced the excessive hydration of CP, prolonging floating and maintaining the mucoadhesiveness. In early attempts, a lengthy process was followed to prepare such an interpolymer complex. In this study, an in situ interpolymer complexation between CP and two grades of PVP (K25 and K90) in 0.1 N HCl was investigated and characterized by Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Hence, directly compressed GR tablets of different combinations of PVP and CP with sodium bicarbonate (SB) as an effervescent agent were examined for prolonged gastroretention and sustained release of ranitidine hydrochloride (RHCl) as a model drug. Tablets were evaluated for in vitro buoyancy, bioadhesiveness, swelling, and drug release in 0.1 N HCl. All GR tablets containing PVP-CP combinations achieved more prolonged floating (>24 h) than CP tablets (5.2 h). Their bioadhesiveness, swelling, and drug release were dependent on the PVP molecular weight and its ratio to CP. Drug release profiles of all formulae followed non-Fickian diffusion. Formula containing the PVP K90-CP combination at a respective ratio of 1 : 3 (P90C13) was a promising system, exhibiting good floating and bioadhesive properties as well as sustained drug release. Abdominal X-ray imaging of P90C13 formula, loaded with barium sulfate, in six healthy volunteers showed a mean gastric retention period of 6.8±0.3 h.

Study Objective: Because it has been hypothesized that histamine2 receptor antagonists (H2 RAs) might interfere with the action of proton pump inhibitors (PPIs) when the drugs are given concomitantly, we sought to compare the pharmacodynamic effects of simultaneous administration of a PPI and an H2 RA with the effects of each drug administered alone., Design: Prospective, randomized, double-blind, three-way crossover study., Setting: Esophageal motility laboratory at a large teaching hospital., Subjects: Twenty-one healthy volunteers., Intervention: Subjects were randomized to one of three treatment arms: an H2 RA (ranitidine 300 mg) plus placebo, a PPI (omeprazole 40 mg) plus placebo, or ranitidine 300 mg plus omeprazole 40 mg, all given once/day at 8 a.m., 30 minutes before a standard breakfast, for 1 week. The subjects then received the other two treatments, with each treatment period separated by a 1-week washout period., Measurements and Main Results: The primary outcome was length of time that the gastric pH remained higher than 4. Secondary outcomes were median gastric pH higher than 4 and percentage of time that the gastric pH remained higher than 4. On day 7, ambulatory intragastric pH was recorded over an 8-hour period in each treatment arm. The combination of ranitidine and omeprazole resulted in a significantly longer time that the gastric pH remained higher than 4 (median 410.5 min [interquartile range (IQR) 298.5-454.25 min]) versus either omeprazole alone (median 356.7 min [IQR 254.9-419.2 min], p=0.023) or ranitidine alone (134.1 min [IQR 99.9-302.5 min], p<0.0001). Median gastric pH was also significantly higher when omeprazole and ranitidine were given in combination (pH 5.92 [IQR 4.75-6.46]) than either omeprazole alone (pH 4.88 [IQR 4.27-6.11], p=0.001) or ranitidine alone (pH 2.31 [IQR 2.04-5.27], p=0.0003). Likewise, the percentage of time that the gastric pH remained higher than 4 was significantly higher when omeprazole and ranitidine were given in combination (median 85.52%) than either omeprazole alone (74.31%, p=0.027) or ranitidine alone (27.94%, p=0.0002)., Conclusion: When a PPI and H2 RA were administered concomitantly 30 minutes before breakfast, the H2 RA did not decrease the acid suppressive ability of the PPI; rather, it improved gastric acid control. Thus these results failed to support the initial hypothesis of this study. Further prospective studies are needed to test these findings in patients with gastroesophageal reflux disease as well as those with erosive esophagitis., (© 2015 Pharmacotherapy Publications, Inc.)

The antipsychotic properties of haloperidol are primarily attributed to its ability to block dopamine D2 receptors. Histaminergic transmission modulates some of the behavioral effects of haloperidol. Hence, the present study investigated the contribution of central histaminergic transmission in the cataleptic and neuroleptic effect of haloperidol respectively, using bar test and conditioned avoidance response (CAR) in a two-way shuttle box. The studies revealed that haloperidol (0.50 or 1 mg/kg, i.p.) exhibited cataleptic behavior and inhibited conditioned avoidance response (CAR) in the doses 0.25 or 0.50 mg in rats. The rats, pretreated centrally (i.c.v.) with histamine precursor, L-histidine (1, 2.5 μg) or histamine neuronal inducer (H3 receptor antagonist), thioperamide (20, 50 μg/rat), showed an enhanced cataleptic effect with sub-maximal dose of haloperidol (0.5 mg/kg, i.p.). Similarly, the neuroleptic effect of haloperidol (0.25 mg/kg, i.p.) in CAR was also potentiated in the rats pretreated with L-histidine (2.5 μg) or thioperamide (50 μg/rat). Further, the cataleptic effect of haloperidol (1 mg/kg, i.p.) was attenuated in rats pretreated with the H1 receptor antagonist, chlorpheniramine (60, 80 μg/rat, i.c.v.) or H2 receptor antagonist, ranitidine (60 μg/rat, i.c.v.). However, the neuroleptic effect of haloperidol (0.5 mg/kg, i.p.) was completely reversed by pretreatment with ranitidine (60 μg/rat, i.c.v.), and partially attenuated by chlorpheniramine (80 μg/rat, i.c.v.). These findings suggest the possible involvement of histaminergic transmission in the cataleptic and neuroleptic effects of haloperidol probably via H1 or H2 receptor stimulation., (Copyright © 2015 Elsevier Inc. All rights reserved.)