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Background: Several analgesics are in use for pain control in patients with acute pancreatitis. Procaine hydrochloride (procaine) has a long tradition and is recommended by the German Society of Gastroenterology and Metabolic Diseases for pain treatment in patients with acute pancreatitis. There is no controlled trial showing that procaine could be effective for pain treatment. Methods: In an open, randomized, controlled trial, 107 patients (76 male, 31 female; mean age 45 ± 12 years) were included and randomized either to receive procaine (n = 55) or pentazocine (n = 52) for pain relief. Procaine 2 g/ 24 h was administered by continuous intravenous infusion, pentazocine 30 mg was administered every 6 h as a bolus intravenous injection. Pentazocine was additionally administered on demand whenever required in patients of both treatment groups and its total consumption was recorded. Pain scores were assessed twice daily on a visual analogue scale. Results: Patients receiving procaine were significantly more likely to request additional analgesics compared to patients treated with pentazocine alone, 98 vs. 44%, respectively (p < 0.001). Procaine did not reduce the amount of pentazocine required for pain control. The amount of pentazocine given in both groups was not statistically significantly different. Recorded pain scores were significantly lower (p < 0.001) in patients in the pentazocine group during the first 3 days of analgesic treatment. From day 4 on there was no significant difference in pain scores among the two groups. Conclusion: Thus, intravenous procaine treatment is not effective for pain control in patients with acute pancreatitis. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

A rapid determination method for pentazocine in human plasma without complicated pretreatments has been constructed by liquid chromatography/mass spectrometry (LC/MS) with sonic spray ionization (SSI) using an Oasis HLB cartridge column. The reliability on our method was investigated for human plasma samples spiked with pentazocine and dextromethorphan as internal standard. The regression equation for pentazocine showed good linearity in the ranges of 30–1,250 and 1,250–10,000 ng ml−1; the detection limit was 19.5 ng ml−1 in human plasma. The sensitivity, accuracy and precision were satisfactory to quantify the wide range of therapeutic to toxic levels. Our method established enabled the determination of a single sample of pentazocine in human plasma only within 4 min, and allowed analysis of more than 100 samples per day. The present method seems applicable for actual cases encountered in the forensic and clinical practices. [Copyright &y& Elsevier]

We compared the brain kinetics of radiolabeled (+)-pentazocine and SA4503, which have a high and selective affinity for sigma1 receptors. Brain uptake of [11C]SA4503 was high after intravenous injection followed by a gradual decrease in mice, whereas that of [3H](+)-pentazocine rapidly decreased. The brain uptake of the two radioligands was dose-dependently reduced, but the reduction of [3H](+)-pentazocine was found at higher doses. Percentages of the saturable binding of [3H](+)-pentazocine was much lower than that of [11C]SA4503. The brain uptake of [3H](+)-pentazocine was greatly blocked by SA4503 at a dose of 2 μmol/kg, while that of [11C]SA4503 was blocked by (+)-pentazocine at a dose of 20 μmol/kg and over. When mice were treated with cyclosporin A, a P-glycoprotein modulator, the uptake of [3H](+)-pentazocine was enhanced, but that of [11C]SA4503 was not. Under control and P-glycoprotein-modulated conditions, the brain uptake of both radioligands was reduced by haloperidol, another representative sigma receptor ligand, to a different extent. We concluded that the P-glycoprotein modulation resulted in the different brain kinetics of the two radioligands. The radiolabeled SA4503 is suitable as an in vivo probe, but radiolabeled (+)-pentazocine is not. Synapse 48:80–86, 2003. © 2003 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Surface ionization (SI), which consists in the formation of positive and negative ions along the course of thermal desorption of particles from a solid surface, was first applied as a detector for gas chromatography (GC), GC-surface ionization detection (SID); we developed many new sensitive methods for the determination of abused and other drugs by GC-SID. Recently, Fujii has devised a combination of SI and a quadrupole mass spectrometer and named this system a surface ionization organic mass spectrometer (SIOMS), which is highly selective and sensitive for organic compounds containing tertiary amino groups. We have tried to apply this mass spectrometer to forensic toxicological study; so far we have succeeded in determining important drugs-of-abuse and toxic compounds, such as phencyclidine (PCP), pethidine, pentazocine, MPTP and its derivatives from human body fluids with high sensitivity and selectivity. In this review, we describe our recent studies on the application of GC–SIOMS to forensic toxicology. [Copyright &y& Elsevier]

1 Sigma (σ) receptors have generated a great deal of interest on the basis of their possible roles in various pathologies, including cytoprotection Although the exact function of sigma-1 (σ[sub1]) receptors is not yet known, their role in the regulation of intracellular Ca[sup2+]. levels and sterol biosynthesis, functions that could be assigned to mitochondria, are the only mechanisms described. 2 Using preparations of purified rat liver and brain mitochondria we demonstrate herein the presence of σ-like binding sites [[sup3]H]( + )-pentazocine, a σ[sub1] radioligand was used to label these sites. 3 In the liver, [[sup3]H] (+ )-pentazocine labelled one class of binding sites with high affinity (K[subd] = 3 nM), similar to that observed in liver microsomes and synaptic membranes. These sites were located on the outer mitochondrial membranes and displayed high affinity for other σ[sub1] ligands namely, haloperidol. ifenprodil. carbetapentane or l,3-dt(2-tolyl)guanidine (DTG). 4 The presence of σ[sub1] receptors on liver mitochondria was confirmed using double fluorescence immunostaining. 5 [[sub3]H] (+ )-pentazocine binding sites were also found on brain mitochondria hut they appeared pharmacologically distinct to the liver ones as [[sub3]H] ( + )-pentazocine and typical σ[sub1] ligands displayed lower affinities for these sites. Nevertheless. [[sub3]H ]( + )-pentazocine binding on both liver and brain mitochondria was modulated by progesterone, a putative endogenous ligand for σ receptors. 6 Our data demonstrates the presence of [[sub3]H] ( + )-pentazocine binding sites with pharmacological characteristics identical to σ receptors on rat liver mitochondrial membranes. The pharmacological significance of these sites and their role on mitochondrial function remain unknown. [ABSTRACT FROM AUTHOR]

Measures the degradation of 4-hydroxyphenylpentazole. Free energies of activation in methanol; Basis for the estimation of the stability of pentazole anion; Methods for preparation of the parent pentazole.

In human neuroblastoma SH-SY5Y cell preparations, σ1 receptor agonists (+)-pentazocine and 1S,2R-(−)-cis-N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)cyclohexylamine (BD737) competed for [3H]haloperidol binding with Ki values of 67±10 and 14±10 nM, respectively. (+)-Pentazocine or BD737 up to 10 μM did not affect basal levels of intracellular Ca2+ concentration ([Ca2+]i) in these cells, but they significantly reduced muscarine-induced [Ca2+]i changes in a dose-related manner. However, the reduction by (+)-pentazocine was not reversed by the σ1 receptor antagonist haloperidol. Further studies showed (+)-pentazocine, BD737 and haloperidol could compete for [3H]quinuclidinyl benzilate binding in SH-SY5Y cells with Ki values of 0.51±0.06, 0.32±0.07 and 4.4±2.3 μM, respectively. Thus, the inhibitory effects on muscarine-induced [Ca2+]i changes by (+)-pentazocine and BD737 in SH-SY5Y cells were likely due to blockade of muscarinic receptors, not due to σ1 receptor activation by these ligands. [Copyright &y& Elsevier]

Sigma-1 receptor (Sig1R) is an endoplasmic reticulum (ER)-related membrane protein, that forms heteromers with other cellular proteins. As the mechanism of action of this chaperone protein remains unclear, the aim of the present study was to detect and analyze the intracellular dynamics of Sig1R in live cells using super-resolution imaging microscopy. For that, the Sig1R-yellow fluorescent protein conjugate (Sig1R-YFP) together with fluorescent markers of cell organelles were transfected into human ovarian adenocarcinoma (SK-OV-3) cells with BacMam technology. Sig1R-YFP was found to be located mainly in the nuclear envelope and in both tubular and vesicular structures of the ER but was not detected in the plasma membrane, even after activation of Sig1R with agonists. The super-resolution radial fluctuations approach (SRRF) performed with a highly inclined and laminated optical sheet (HILO) fluorescence microscope indicated substantial overlap of Sig1R-YFP spots with KDEL-mRFP, slight overlap with pmKate2-mito and no overlap with the markers of endosomes, peroxisomes, lysosomes, or caveolae. Activation of Sig1R with (+)-pentazocine caused a time-dependent decrease in the overlap between Sig1R-YFP and KDEL-mRFP, indicating that the activation of Sig1R decreases its colocalization with the marker of vesicular ER and does not cause comprehensive translocations of Sig1R in cells., Competing Interests: The authors have declared that no competing interests exist.

Objective: To measure postoperative pain relief following the use of rectal diclofenac combined with intramuscular pentazocine compared with intramuscular pentazocine alone in patients undergoing a caesarean delivery., Methods: This single-blind randomized controlled trial enrolled pregnant women that had a caesarean section at the Enugu State University of Science and Technology Teaching Hospital, Enugu, Nigeria. Study participants were randomized to receive either 100 mg of rectal diclofenac given every 12 h plus 30 mg of intramuscular pentazocine given every 6 h (group A) or 60 mg of intramuscular pentazocine given every 6 h (group B). The primary outcome was the level of pain as measured using a visual analogue scale. The secondary outcomes were the level of satisfaction with pain relief and need for rescue analgesia., Results: A total of 200 participants were randomized equally into the two groups. Participants in group A had significantly better pain control and satisfaction over the 48 h after surgery compared with group B. Significantly more of group B required rescue analgesia for breakthrough pain compared with group A., Conclusion: Rectal diclofenac combined with intramuscular pentazocine was significantly better at controlling pain compared with pentazocine alone in the first 48 h following caesarean section. Trial registration number: PACTR202107706925314 at www.pactr.org on 28 July 2021.

Background: Strict adherence to pharmacological dosage regimens is a prerequisite to the success of most treatments, particularly for patients in drug abuse programs. The compliance of tramadol, an atypical non-scheduled narcotic analgesic, using objective method has not been adequately studied in an Indian setting., Aim: To evaluate the compliance and pattern of drug use among opioid-dependent subjects prescribed tramadol based on urinalysis., Method: Fifty male opioid-dependent patients (ICD 10), seeking treatment at a tertiary de-addiction treatment centre of North India on tramadol prescription for atleast past four weeks were included. Self-reported substance use was recorded using semi-structured proforma. Ten ml of urine was collected for the assessment of compliance of tramadol of other substance use (morphine, buprenorphine, dextropropoxyphene, pentazocine, cannabis, benzodiazepines, pheniramine). All these drugs were analyzed using the immunoassay-based Cassette test and Gas Chromatography in human urine., Result: Mean age of the participants was 42.8 years and the mean duration of opioid use was 15.9years. The urine specimen of all subjects tested positive for tramadol. Urinalysis revealed benzodiazepines, cannabis, and pheniramine to be the most common substances of use in this population. It was seen that agreement of self-reporting and urine test results was good for morphine (κ = 0.558) and cannabis (κ = 0.312) and was poor for buprenorphine, pentazocine, and pheniramine., Conclusion: The study demonstrates the continued use of several illicit or non-prescribed medications in a medication-assisted opioid treatment population. The results affirm the reliability of urinalysis as an adjunct for testing compliance in such a population., (Copyright © 2022. Published by Elsevier B.V.)

Background: Nonmedical use of prescription drugs for recreational purposes is a major health problem that raises high concerns for public health. Recently, several laboratory studies have reported the misuse of pentazocine, an agonist-antagonist opioid in combination with antihistamines in opioid addicts. Illicit self-administration of prescription drugs has been increasingly reported in India. Urinalysis as an adjunct to self-report plays a key role in providing additional information in the treatment of drug users. This paper aims to discuss a simple, convenient, and rapid capillary column gas-liquid chromatography method for simultaneous detection of pentazocine, pheniramine, and cotinine in urine., Methods: The sample was extracted with chloroform and isopropanol (3:1,v/v) and evaporated to dryness. After reconstitution with methanol, it was directly subjected to gas chromatography analysis. Method performance was evaluated and validated in terms of sensitivity, precision, the limit of detection (LOD), and the limit of quantification (LOQ)., Findings: The linearity obtained was in the range of 50-1000 ng/ml with a correlation coefficient (r) above 0.999 for each drug. Good LOQ (50ng/ml) was obtained with each drug. Also, the developed method was effective in analyzing samples from patients with suspected abuse of these drugs., Conclusion: The technique was found to be simple, robust, sensitive, and precise in the simultaneous analysis of drugs (pentazocine, pheniramine, and cotinine). This method was proved to be useful and cost-effective in treating and monitoring patients seeking help for addiction in clinical settings., (© 2022 Kerman University of Medical Sciences.)

Contracture is limitation of complete range of motion,active or passive, due to joint, muscle or soft-tissuelimitations. Myogenic contractures can be due to trauma,inflammation, degenerative changes, ischemia, andspasticity. A 32-year-old patient presented with complaintsof inability to sit on the floor and limitation of multiplejoint movements which progressed over the past threeyears. He had a history of multiple drug injections(pentazocine) for the past six years at multiple sitesthroughout the body. He was started on narcoticanalgesics for chronic abdominal pain followingpancreatitis. Deltoid, quadriceps, hamstring and calfmuscles were indurated and contracted. Bilateral wingingof scapula was present. Contractures are commonlyassociated with joint diseases; but normal radiographsand indurated muscles support a myogenic pathology inthis case. Myogenic contracture due to parenteral narcoticabuse is a rare entity.

Dezocine and pentazocine, widely prescribed in China for postoperative pain, were initially considered as mixed agonist/antagonist targeting μ-opioid receptors (MORs) and κ-opioid receptors (KORs). However, dezocine has been revealed to alleviate chronic neuropathic pain through MOR activation and norepinephrine reuptake inhibition (NRI). This study investigated dezocine- and pentazocine-induced antinociception and physical dependence development, compared to the typical MOR-NRI opioid tapentadol. Calcium mobilization assay was conducted to assess the potency of the drugs while hot-plate test was performed to compare the antinociception. Physical dependence development was compared with morphine. Treatment with dezocine, pentazocine and tapentadol stimulated calcium mobilization in HEK293 cells stably expressed MORs but not KORs, whereas dezocine and pentazocine inhibited KOR activities. Subcutaneously injected dezocine-, tapentadol- and pentazocine-induced antinociception dose-dependently, in hot-plate test. Intrathecally injected MOR antagonist CTAP, norepinephrine depletor 6-OHDA and α 2 -adrenoceptor (α 2 -AR) antagonist yohimbine partially antagonized dezocine, pentazocine and tapentadol antinociception. Whereas specific KOR antagonist GNTI did not alter their antinociception, the putative inverse KOR agonist nor-BNI reduced dezocine and pentazocine antinociception. Moreover, combined CTAP and 6-OHDA or yohimbine blocked dezocine and tapentadol antinociception but displayed the same partial inhibition on pentazocine antinociception as CTAP alone. Furthermore, compared to morphine and pentazocine, long-term treatment with dezocine and tapentadol produced much less physical dependence-related withdrawal signs, which were restored by spinal 6-OHDA or yohimbine treatment. Our findings illustrated that dezocine and tapentadol, but not pentazocine, exert remarkable antinociception in nociceptive pain with less abuse liability via dual mechanisms of MOR activation and NRI. [Display omitted] • Dezocine and tapentadol produce antinociception by dual mechanisms of MOR-NRI. • Norepinephrine reuptake inhibition is not involved in pentazocine-induced antinociception. • Tapentadol and dezocine produce less physical dependence than pentazocine and morphine due to NRI. [ABSTRACT FROM AUTHOR]

Radioligand analysis was used to study the interaction between afobazole and sigma-1 receptors (Sigmar1) in the brains of inbred C57B1/6, BALB/c, and mongrel CD-1 mice. Afobazole binding sites were found to be identical to those of the prototype Sigmar1 agonists (+)-pentazocine and PRE-084. Depending on the structure of the prototype ligand and the in vitro incubation conditions, the specific binding of afobazole with Sigmar1 in brain homogenates from inbred mice was characterized by different receptor interaction models. In competitive displacement of [G-H]PRE-084, the affinity of Sigmar1 for afobazole in BALB/c mice was significantly greater than that in C57B1/6 and CD-1 mice. [ABSTRACT FROM AUTHOR]

Pentazocine is a mixed agonist/ antagonist opioid analgesic agent that can induce an atypical myopathy following intramuscular injections. Thi iatrogenic myopathy is rare, typified by fibrosis, and should be differentiated from other myopathies. We describe a case of pentazocine-induced myopathy that caused wasting of musculature in the gluteal region bilaterally and stiffness and woody induration in the legs of 42-year-old man. Though rare, clinicians should be alerted to this potential side effect and avoid repeated administration of intramuscular pentazocine. [ABSTRACT FROM AUTHOR]

Background: Post-caesarean section pain is a problem i n our environment. Though many modalities for pain management exist, there is the need to investigate safer and affordable regimens that will provide adequate analgesia with minimal side effects and with ease of administration. Alternating doses of intramuscular acetaminophen and intramuscular pentazocine was studied as an alternative to provide safe and effective post-caesarean section analgesia. Its effectiveness and side effect profile in our environment have not been previously investigated., Aims and Objectives: The study aimed to compare the analgesic and side effect profile of intramuscular pentazocine with another regimen involving alternating doses of pentazocine and acetaminophen within the first 48hours after surgery., Design of the Study: This was a prospective, comparative and randomized study among 142 women who voluntarily consented to the study and had elective caesarean section from May 2014 to May 2015 at the Ahmadu Bello University Teaching Hospital, Zaria. Setting: The Study was conducted at the obstetrics and gynecology department of the teaching hospital of Ahmadu Bello University, Zaria., Materials and Methods: Consecutive eligible pregnant women who were slated for elective caesarean section were recruited at the antenatal clinic unit of the department and randomized using the WINPEPI software by Abramson to either receive intramuscular pentazocine or alternating doses of pentazocine and acetaminophen over the first 48hours after surgery. The pain scores, side effect profile and the time taken for the return of bowel sounds were compared among the two groups using relevant statistical methods with IBM SPSS version 20 with Z tests and chi-square to test for strength of relationships of variables. The level of significance was 0.05., Results: The average age of the participants was 29.82years with standard deviation 6.138; 64.8% were Hausa-Fulani, 71.83% were Muslims, 45.07% were unemployed, 97.89% were married, 42.2% were multiparous, 59.86% booked in our centre and 59.2% were having their first caesarean section. Seventy-six participants received combination of injection pentazocine/acetaminophen while 66 received pentazocine injection alone. The drop-out rate was 8.5%. There was no statistically significant difference in the pain scores both on the visual analogue scale and the verbal rating scale in the first 48hours in both groups, no difference in the need for rescue analgesics (p=0.709), time taken for the return of bowel sounds (P=0.391), incidence of side effects (p=0.394) and participants' level of satisfaction (p=0.255)., Conclusion: Both regimens were comparable in analgesic efficacy, incidence of side effects and satisfaction levels., Competing Interests: The Authors declare that no competing interest exists., (Copyright © 2022 by West African Journal of Medicine.)

Pentazocine (PTZ) is a widely used drug for postoperative pain. It should be administered at appropriate dosing intervals not only because of its morphine-like side effects but also because frequent inappropriate dosing can lead to dependence. Although perioperative patients reportedly have nonnegligible effects on placebo drugs and postoperative wound healing, no pharmacokinetic (PK)/pharmacodynamic (PD) model has been established and simulated using real-world data for the perioperative period. This study aimed to perform PTZ modeling and simulation and to establish an indicator of the timing of drug efficacy evaluation in clinical practice. Participants were in-hospital orthopedic surgery patients who received 15 mg of PTZ within 48 h postoperatively. Pain severity was assessed using the numerical rating scale (NRS). A two-compartment model was selected for the population PK model and an indirect response model for the PK/PD model. Using these models, a virtual population of 1000 patients with Pain base NRS of 5 and 6 and body weights of 40, 80, and 120 kg were treated with single and multiple PTZ administrations (4, 8, and 24 h apart) of 15 mg. Simulation results indicate that its analgesic efficacy should be evaluated within 1 h after administration of 15 mg of PTZ. Additional doses should be considered every 8-12 h in postoperative patients with Pain base NRS of 5 weighing 40-80 kg. Simulation using the PK/PD model developed in this study may provide useful information for determining the analgesic effects and timing of the dosing interval after PTZ administration in perioperative patients.

Investigates whether the omega-ligand (+)-pentazocine depresses M current and enhances calcium conductances in frog melanotrophs. Composition of external solutions used in electrophysiological experiments; Effects of (+)-pentazocine on outward potassium current in a melanotroph.

Presents information on a study which discussed the mechanisms involved in the delta-ligand-induced stimulation of the electrical activity in pituitary cells. Isolation of the sustained outward potassium current; Properties of the sustained outward potassium current; Effects of positive-pentazocine on the kinetic properties of the sustained outward potassium current.

Background: To evaluate the efficacy of endoscopic variceal ligation (EVL) in prophylactic therapy for oesophageal varices, we performed a randomized prospective trial to compare the recurrence of oesophageal varices treated by EVL with those treated by endoscopic injection sclerotherapy. Methods: Fifty patients with liver cirrhosis were divided into two groups at random, after informed consents were obtained, to receive prophylactic therapy for bleeding of oesophageal varices. Group 1 patients underwent sessions of sclerotherapy with 5% ethanolamine oleate used as the sclerosant. Group 2 patients underwent EVL followed by one or two sessions of sclerotherapy. Results: During the 18 month follow-up period, both the recurrence rate in group 2 (56%) and the incidence of bleeding (20%) were significantly higher compared with group 1 (recurrence rate 16%, bleeding 0%). Conclusions: This result indicates that EVL is not effective for prophylactic therapy for oesophageal varices in liver cirrhosis. [ABSTRACT FROM AUTHOR]

Abstract Rationale: A common treatment strategy for the management of severe pain involves the co-administration of multiple opioid analgesics. Due to the increasing popularity of this practice, it is becoming increasingly important to understand the interactions between clinically employed opioids under a wide range of conditions. Objective: The purpose of the present investigation was to examine the effects of opioid combinations following acute and chronic administration of the low-efficacy mu-opioid butorphanol, and to determine if the effects of these combinations are modulated by the intensity of the nociceptive stimulus. Methods: In a warm-water, tail-withdrawal procedure, rats were restrained and the latencies to remove their tails from 50 Celsius (low temperature) and 55 Celsius (high temperature) water were measured following both acute and chronic administration of butorphanol. Opioids possessing both high (etorphine, levorphanol, morphine) and low [dezocine, (-)-pentazocine, nalbuphine] relative efficacy at the mu receptor were examined. Results: Under acute conditions, etorphine, levorphanol, morphine and dezocine increased tail-withdrawal latencies at both low and high temperatures, whereas (-)-pentazocine, nalbuphine and butorphanol increased latencies only at the low temperature. A dose of 30 mg/kg butorphanol increased the effects produced by these opioids at the low temperature, but antagonized the effects of etorphine, levorphanol, morphine and dezocine at the high temperature. During chronic treatment with 30 mg/kg per day butorphanol, tolerance was conferred to the antinociceptive effects of all the opioids examined, with greater degrees of tolerance conferred to those opioids possessing low efficacy at... [ABSTRACT FROM AUTHOR]

Buccoadhesive compacts (BCs) of pentazocine (PZ) were prepared by the direct compression method using polymers like carbopol 974P (CP 974P) and hydroxypropyl methylcellulose (HPMC K4M) in ratios of 1:0 (batch B1), 1:1 (B2), 1:2 (B3), 1:4 (B4), and 0:1 (B5). The compacts were evaluated for thickness uniformity, weight variation, drug content uniformity, and swelling index. Swelling was increased with an increase in HMPC K4M content in the compacts. An in vitro assembly was developed to measure and compare the bioadhesive strength of compacts. The maximum bioadhesive strength was observed in compacts formulated with a combination of CP 974P and HPMC K4M. The compacts were evaluated in vitro for 24 hr in pH 6.6 phosphate buffer using a standardized dissolution apparatus. The data were evaluated by a simple power equation (Mt/M∞ = Ktn); it was observed that all the compacts followed non-Fickian release kinetics. Some of the buccoadhesive compacts were evaluated in vivo in rabbits. The compacts gave controlled blood level profiles with a twofold to threefold increase in area-under-the-curve (AUC) values in comparison to oral administration of aqueous drug solution. [ABSTRACT FROM AUTHOR]