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In our present investigation, a series of novel 4-methoxy-1,3-benzenediolyl-hydrazones were designed and synthesized, and their ability to inhibit platelet aggregation was evaluated by adenosine diphosphate (ADP) and arachidonic acid (AA). The structures of the synthesized compounds were confirmed by spectral data. Results demonstrated that the activities of all compounds excelled the positive drug Picotamide (25.1% inhibition rate) and seven compounds (PNN01, PNN03, PNN05, PNN07, PNN09, PNN12, and PNN14) have efficiently inhibited platelet aggregation even higher than Clopidogrel (37.6% inhibition rate) induced by AA. Among them, PNN07 (39.8% inhibition rate) was considered as the most potent analogue. Evaluation of cytotoxic activity of the compounds against L929 cell line revealed that none of the compounds have significant cytotoxicity. Thus, diolylhydrazones derives are potential to be antiplatelet aggregation inhibitors and maybe working in AA-induced selectively.

Effects of picotamide and zileuton on tonic contractile activity of the rat portal vein preparations, induced by acetylcholine (2.10(-5) mol/1) and phenylephrine (5.10(-7) mol/1) were investigated. Conversion of arachidonic acid products (prostaglandins, leukotrienes) synthesized by endothelial cells, plays an important role in the local regulation of vascular tone. The compounds formed in a cascade of enzymatic transformations can modulate the effect of other vasoactive factors. Picotamide (6,5.10(-5) mol/1) - thromboxane receptor and thromboxane -synthase blocker - depress acetylcholine-induction tonic contraction of isolated segments of portal vein with intact endothelium by 29% and norepinephrine-induction reduction of 45% relative to the control values. The obtained results indicate a participation of thromboxane and/or endoperoxide H2 in this reaction. Partial inhibition of the contractions by 5-lipoxygenase blocker zileuton(4,2.10(-5) mol/1) at 23% relative to control values suggests, that products of lipoxigenase pathways of arachidonic acid conversion are involved in mechanisms of specified reactions. These data indicate complex mechanisms of regulation of vascular tone of the portal vein, which play an important role eicosanoids. Further study of these mechanisms is necessary for the formation of basic knowledge, as well as to elucidate the mechanisms of occurrence and development of pathological conditions of vessels and the development of methods of their correction.

Picotamide has previously been shown to inhibit the platelet binding of thromboxane A2 analogues. Picotamide has been also reported to inhibit thromboxane A2 synthase so that an intracellular target for its action has been postulated. A carrier-mediated active transport for thromboxane A2 (TxA2) was previously reported in platelets. In the present paper the effect of picotamide on the internalization process was assessed. The kinetics of the TxA2 binding to and internalization by human platelets from 6 male healthy volunteers were investigated by a radiolabeled structural TxA2 analogue,125I-PTA-OH, in the absence and in the presence of increasing concentrations of picotamide. The kinetic constants (kobs, k1, and k−1) were calculated by time course experiments according to Weiland and Molinoff. The affinity constant (Km) and maximal uptake velocity (Vmax) values for each subject were determined by the double reciprocal plot of Lineweaver-Burk. The kinetically determined dissociation constant Kd was 10 nmol/L. In the uptake experiments the association rate of the nondisplaceable binding was found to be saturable at increased ligand concentration with a Michaelis-Menten type of kinetics. Picotamide was able to inhibit the internalization process with a Ki of 7100µmol/L

Andrea Celestini, Francesco VioliIV Divisione di Clinica Medica, Department of Experimental Medicine and Pathology, University of Rome “La Sapienza,” ItalyAbstract: Picotamide is an antiplatelet drug with a dual inhibitory action. Thus, picotamide inhibits both thromboxane A2 (TxA2) receptors and TxA2 synthase and, at variance with aspirin, does not interfere with endothelial prostacyclin (PGI2) production. Two large randomized trials have been performed to assess the clinical efficacy of picotamide in patients at risk of atherothrombosis. The ADEP study compared peripheral artery disease (PAD) patients randomized to picotamide or placebo. This study did not show a significant reduction of cardiovascular events by picotamide but a subgroup analysis showed its potential usefulness in patients with diabetes. To investigate this issue further, the DAVID study recently enrolled diabetic patients with PAD randomized to picotamide versus aspirin; the results showed a significant reduction of overall mortality in the picotamide group. Moreover long-term picotamide treatment in diabetes promotes the reduction of microalbuminuria and the inhibition of growth of carotid plaques. These data suggest that picotamide may represent an interesting drug to be further investigated in future trials in the atherothrombotic setting.Keywords: picotamide, aspirin, diabetes, cardiovascular events, peripheral artery disease

Type 2 diabetes mellitus (DM) and peripheral arterial disease (PAD) are two very relevant cardiovascular (CV) risk factors, which can often be found concurrently in the same patient. The DAVID trial, a double-blind, randomized, aspirin(ASA)-controlled study, has demonstrated that the use of picotamide, a thromboxane A2 synthase and receptor dual inhibitor, is associated with lesser CV morbidity and mortality in this type of patients in comparison to ASA, considered the standard antiplatelet agent. In order to estimate clinical and economic impacts of picotamide in the Italian health care setting, we developed a pharmacoeconomic model based on clinical data from DAVID and national economic parameters and demographics. The base case scenario, which reflects current prices and reimbursement policy (i.e. ASA fully paid for, picotamide out-of-pocket for patients) yielded an incremental cost/effectiveness ratio (ICER) of about 8,500 euro/year of life (YOL) saved, which falls below conventionally adopted willingness to pay thresholds. This cost, however, is totally born by the patient, while the savings on health care expenditures for avoided events (and less ASA) benefit the national health service (NHS). These results may help the physician in explaining the consequences of this choice to his/her patients, facilitating a fully-informed choice. The availability of a theoretical model allowed to explore some alternative scenarios, that indicate that the ICER can be further lowered and the economical burden better distributed through policy changes. In conclusion, the pharmacoeconomic model indicated that picotamide is likely to be a cost/effective option for CV mortality and morbidity prevention in patients with concurrent type 2 DM and PAD and that the level of adoption of this strategy will depend on willingness to pay and policy priorities of the NHS and patients themselves.

Aims Patients with diabetes are at excessive risk of mortality and cardiovascular morbidity. Previous studies suggest that aspirin may be less effective in diabetic patients. In this multi-centre, randomized, double blind trial picotamide, a dual inhibitor of thromboxane A2 synthase and receptor, was compared with aspirin for the prevention of mortality and major cardiovascular events in diabetics with peripheral arterial disease (PAD). Methods and results A total of 1209 adults aged 40–75 years with type 2 diabetes and PAD were randomized to receive picotamide (600 mg bid) or aspirin (320 mg od) for 24 months. The cumulative incidence of the 2 years overall mortality was significantly lower amongst patients who received picotamide (3.0%) than in those who received aspirin (5.5%) with a relative risk ratio for picotamide versus aspirin of 0.55 (95% CI: 0.31–0.98%). Events were reported in 43 patients (7.1%) on picotamide and 53 (8.7%) on aspirin. The combined endpoint of mortality and morbidity had a slightly lower incidence in the picotamide group but this difference did not reach statistical significance. Conclusion Picotamide is significantly more effective than aspirin in reducing overall mortality in type 2 diabetic patients with associated PAD.

OBJECTIVE: Scavenging of vascular endothelial growth factor (VEGF) elevates blood pressure (BP) in patients receiving anti-angiogenic therapy. Similarly, inhibition of circulation VEGF by its soluble receptor fms-like tyrosine kinase-1 (sFlt-1) underlies BP elevation in pre-eclampsia. Both phenotypes are characterized by augmented production of endothelin-1 (ET-1), suggesting a role for ET-1 in anti-angiogenic hypertension. We aimed to assess the effect of VEGF inhibition on ET-1-induced contractility and downstream ET-1 signaling. APPROACH AND RESULTS: Male C57BL/6N mice were treated with either sFlt-1 or vehicle and BP was assessed via tail-cuff. Mean arterial pressure of sFlt-1-treated mice markedly increased compared to vehicle-treated controls (N = 11-12, p

2-1(4-Cyanophenyl)aminol-3-chloro-1,4-naphthalenedione (NQ-Y15) is a dual action drug which acts as a thromboxane A2 (TXA2) synthase inhibitor and TXA2/PGH2 receptor antagonist. In the present study, we examined the effects of NQ-Y15 on Ca2+ mobilization, which is the common event in various types of platelet activation, in arachidonic acid (AA)-stimulated rat platelets. The elevation of cytosolic Ca2+ concentration ([Ca2+]i) induced by AA was inhibited by NQ-Y15 in a concentration-dependent manner. This inhibition-effect of NQ-Y15 was found to be based on the suppression of the rise in [Ca2+]i by the inhibition of both Ca2+ release from internal stores and Ca2+ influx from the extracellular space. Our successive trial was focused on the role of cyclic AMP (cAMP) in the action of NQ-Y15, because cAMP was reported to be increased by dual action drugs such as picotamide and to inhibit the increase in [Ca2+]i. NQ-Y15 was confirmed to increase cAMP in AA-stimulated rat platelets. These results suggested that NQ-Y15 might inhibit the rise in [Ca2+]i in AA-treated rat platelets by increasing cAMP, which is involved in the inhibition of platelet activation.

In a controlled, randomized, 6-year trial the safety and efficacy of picotamide, a dual-action antithromboxane agent, were assessed in 50 patients with type 2 diabetes mellitus at increased risk of thrombotic vascular events. The patients were randomized to two groups of equal size and received 900 mg picotamide daily or placebo. After phase I (double-blind; years 1–2), patients receiving placebo were treated, if necessary, with antiplatelet drugs (aspirin, ticlopidine) while members of the other group continued to receive 600 mg picotamide daily. In the course of the study 21 vascular events occurred: 16 in the group receiving placebo (fatal myocardial infarction, n = 7; non-fatal stroke, n = 3) and five in the group receiving drug (fatal myocardial infarction, n = 2) ( P < 0.005; Fisher's exact test). One patient (placebo group) died of malignant disease. During the initial double-blind phase a total of nine vascular events was observed (six and three in the groups receiving placebo and drug, respectively). Picotamide treatment was well tolerated and no major side-effects were observed during the study periods.

Pancera P, Sansone S, Secchi S, Covi G, Lechi A (University of Verona, Verona, Italy). The effects of thromboxane A2 inhibition (Picotamide) and angiotensin II receptor blockade (Losartan) in primary Raynaud's phenomenon. J Intern Med 1997; 242: 373–6. Objectives To assess the role of thromboxane A2 and of angiotensin II in patients with primary Raynaud's phenomenon. Design After an eight-day run-in period, the patients were enrolled in a single-blind, cross-over, study. Setting Patients were examined at the Ambulatory for Microcirculatory Diseases of the Clinic of Internal Medicine, University Hospital, Verona. Subjects Fifteen subjects affected by primary Raynaud's phenomenon were included. Main outcome measures A piezoelectric plethysmography to evaluate the distensibility of the digital arteries as the ratio between peak time (PT) and total time (TT), and an oscillometric blood pressure recorder were used after the run-in period, and after a two-week course of picotamide (300 mg b.i.d., i.e. two times daily) or losartan (12.5 mg once daily) with an interval of a week of placebo between the active treatments. The tests were performed after every treatment in basal condition and during mental stress. The patients reported in a diary the number and the severity (from 0 to 4 +) of the vasospastic crises. Results The change in TP/TT ratio appeared statistically significant only after losartan treatment, both in basal condition and during mathematical stress. Both pharmacological treatments, with respect to placebo, showed an improvement of the scores, derived from the number and severity of vasospastic attacks, but only the therapy with losartan determined a statistically significant improvement. Conclusions The inhibition of the type 1 receptor for angiotensin II seems highly effective in the reduction of the vasospastic crises in the subjects with primary Raynaud's phenomenon. According to our experience, losartan could be used more extensively in the treatment of these patients besides arterial hypertension.

Picotamide is a dual TxA2 receptor antagonist/Tx A2 synthetase inhibitor. As the picotamide effect is maximum only after 5–10 min of incubation, aim of the present work was to study whether the effect of picotamide could be observed even after wash out of the drug from the external buffer. Platelet aggregation, serotonin release and changes in intracellular calcium were analyzed in platelets treated with picotamide and then gel-filtered, in comparison with gel-filtered platelets treated with picotamide. To exclude the possibility that the inhibitory effect of picotamide is due to its intracytosolic storage, serotonin release in digitonin-permeabilized platelets was measured. Platelet aggregation and serotonin release in response either to U46619, a synthetic agonist of the thromboxane A2 receptor, or arachidonic acid or collagen, as well as the changes in intracellular calcium concentration after U46619 or arachidonic acid stimulation, were inhibited by picotamide even when it had been washed out by gel-filtration. Both inhibitions were very similar to that observed in experiments in which picotamide was present in the medium. As the serotonin release in digitonin permeabilized platelets presented the same inhibition it may be excluded that picotamide effect is consequent upon the cytosolic storage of the drug. Since our results clearly indicate that the action of picotamide persists even after washing out of the drug from the medium, the idea that this antagonistic effect may be dependent on its binding to platelet plasma membrane rather than on its cytosolic concentration, is strongly substantiated. Copyright © 1997 Elsevier Science Ltd

Inhibition of prostate smooth muscle contraction is an important strategy for medical treatment of lower urinary tract symptoms (LUTS). Besides α1-adrenoceptors, prostate smooth muscle contraction is induced by activation of thromboxane (TXA2) receptors (TXA2-R). Here, we examined the effects of the TXA2-R antagonist picotamide on contraction of human prostate tissue. Prostate tissues were obtained from radical prostatectomy. The effects of picotamide (300 μM), L-665,240 (3 μM), and seratrodast (3 μM) on U46619-, electric field stimulation- (EFS-), phenylephrine-, and norepinephrine-induced contractions were studied in organ baths. Expression of TXA2-R and TXA2 synthase (TXS) was examined by fluorescence stainings. Picotamide, seratrodast, and L-655,240 inhibited concentration-dependent contractions induced by the TXA2 analog U46619. Picotamide, but not seratrodast or L-655,240, inhibited frequency-dependent contractions induced by EFS. Picotamide inhibited concentration-dependent contractions induced by norepinephrine or by the selective α1-adrenoceptor agonist phenylephrine. In prostate strips, where only submaximal contraction by a low dose of phenylephrine was induced, application of U46619 raised tone to maximum phenylephrine-induced tension. Immunoreactivity for TXA2-R and TXS was observed in the stroma and in epithelial cells of glands. Colocalization of both immunoreactivites was observed with the smooth muscle markers calponin and α-smooth muscle actin, with the epithelial marker pan-cytokeratin, and with prostate-specific antigen in the stroma and glands. The receptor antagonist picotamide inhibits α1-adrenergic, TXA2-mediated, and EFS-induced contractions in the human prostate. To the best of our knowledge, this is the first antagonist able to inhibit two different contraction systems in the prostate.

Background : Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A 2 has been proposed as a possible inflammatory mediator ; its suppression may be a useful therapeutic option. Methods : Using a tissue incubation technique, we compared release of immunoreactive thromboxane B 2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. Results : Increased amounts of thromboxane B 2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147-325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61-140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64-206), 8). Incubation with picotamide at concentrations between 100 μM and 1 mM reduced thromboxane B 2 release (IC 50 890 μM). Conclusion : Since increased thromboxane A 2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease.

This editorial refers to "Picotamide, a combined inhibitor of thromboxane A2 synthase and receptor, reduces 2 year mortality in diabetics with peripheral arterial disease: the DAVID study" " by GGN Serneri et al. on page 1845 . It is only in the last decade or so that peripheral arterial disease (PAD) has come to the general attention of clinicians as a condition that can greatly increase the risk of ischaemic cardiovascular events and mortality, and it is only lately that actions have been undertaken to increase the awareness of this clinical condition and to institute appropriate therapies aimed at reducing the incidence of adverse cardiovascular events. Thus, PAD has rapidly transformed from a largely overlooked condition, managed solely by a 5-word prescription (stop smoking and go walking), to a disease requiring multi-therapeutic interventions and extensive programmes of detection. The initial lack of attention to these patients is witnessed by the small number of PAD patients enrolled in the early studies of prevention of cardiovascular events by antiplatelet agents in patients at risk. Indeed, no direct evidence on the efficacy of aspirin in patients with PAD exists, and the indication to use aspirin in this clinical condition1 comes mainly from the meta-analysis of the antithrombotic trialists' collaboration2 or from extrapolation of trial results from similar high risk conditions.3 More recently, the concept of atherothrombosis as an underlying condition common to cerebrovascular, cardiac and peripheral arterial disease has emerged and many more patients with PAD have been included in secondary or primary prevention trials.2,4–6 The analysis of the subgroup of PAD patients in these trials has shown that those with intermittent claudication and a reduced ankle/brachial index (

We compared the effects of two antiplatelet agents, picotamide, a dual antithromboxane inhibitor, and aspirin, a nonselective cyclooxygenase inhibitor, on microalbuminuria and cutaneous microcirculation in diabetic patients. Twenty patients with type II diabetes mellitus with micro- or macroalbuminuria (urinary albumin excretion rate ⩾ 30 mg/24 h) (8 men, 12 women; mean age, 62 ± 3 years) were enrolled in an open-label, 3-month pilot study and randomly assigned to receive picotamide 300 mg twice daily (10 patients), or aspirin 325 mg/day (10 patients). The 24-hour urinary albumin excretion rate was measured at baseline and after 3 months using a commercial radioimmunoassay kit. Cutaneous microcirculation was assessed at the same time by means of laser-Doppler flowmetry. Supine resting flow (RF) and standing flow (SF) (after 3 minutes in the upright position) were also measured. The arteriovenous response (AVR) was calculated as (RF — SF)/RF × 100. The microangiopathy index (MI) was expressed as the ratio AVR:RF. Urinary albumin excretion rate increased significantly ( P P = not significant). Urinary albumin excretion rate increased in 6 patients in the aspirin group and in 1 patient in the picotamide group ( P P P

Background and Purpose We assessed the effects of long-term treatment with picotamide, an antiplatelet agent with dual antithromboxane activity, on the evolution of early asymptomatic carotid atherosclerotic lesions in diabetic patients. Methods In a double-blind, placebo-controlled, 2-year study, 50 type II normotensive diabetic patients (35 men; mean age, 66±5 years) with asymptomatic mild or moderate nonstenotic ( Results At baseline, mean±SD numbers of carotid atherosclerotic lesions per patient were 2.7±1.8 and 2.2±1.2 in the picotamide and placebo groups, respectively. Mean±SD percent stenosis was 25.3±7% in the picotamide group and 27.3±6% in the placebo group. Forty-nine patients completed the study. At month 24, the placebo group (n=24) showed a significant progression in number of carotid atherosclerotic lesions (3.04±1.8; P P P P P =.07). Conclusions In diabetic patients compared with patients receiving placebo, long-term treatment with picotamide can slow the evolution of early carotid atherosclerotic lesions, inhibiting progression of plaque number and growth.

A double-blind, placebo-controlled, multicenter clinical trial was carried out in 2304 patients with peripheral vascular disease to assess the effectiveness and safety of picotamide, a new antiplatelet agent, 300 mg orally TID, in comparison with placebo for an 18-month period. The effectiveness of the treatments was assessed by comparing the incidence of cardiovascular events (ie, death, myocardial infarction, stroke, amputation, angina, transient ischemic attack [TIA]) during the study. The safety was assessed by monitoring the adverse reactions (ADRs) in terms of their severity, duration, relationship to treatment, evolution, and consequences. The ADRs were classified according to the World Health Organization coding system. Blood pressure, electrocardiogram (ECG), and routine laboratory tests were also monitored throughout the study. Eighty-four percent of the patients were males, aged between 40 and 75 years. One hundred sixty-five of 1150 patients receiving picotamide (14.3%) and 156 of 1154 receiving placebo (13.5%) complained of at least one ADR. The total number of ADRs reported in the case report forms were 240 for picotamide and 239 for placebo. The most frequent ADRs were abdominal pain (8.3%), nausea (1.3%), headache (1.1%), pruritus (1.0%), and vertigo (0.8%), with a similar incidence with picotamide and placebo. Thirty-one ADRs required withdrawal from the study (18 picotamide and 13 placebo), while 34 were classified as severe even if they did not require withdrawal. Only 17 of these 65 ADRs were considered as probably or possibly related to the treatment (nine picotamide and eight placebo). No relevant changes were found in blood pressure, ECG, or laboratory evaluations during treatment. In the present study picotamide was shown to be an effective and well-tolerated antiplatelet drug, with an incidence of ADRs similar to that of placebo and lower than that of other drugs of the same class. This confirms the safety profile of picotamide based on toxicologic and pharmacokinetic data.

SummaryIt was the aim of the present study to investigate if antiplatelet treatment reduced cardiovascular events in patients with claudication and/ or an ankle/brachial index (ABI) ≤0.99 and to analyse if specific antiplatelet treatment had a different impact on clinical outcome. We performed a meta-analysis of 29 clinical randomized trials on antiplatelet therapy for prevention of vascular death, myocardial infarction, and stroke in 10,735 peripheral artery disease patients. The primary end-point utilizing in the meta-analysis construction was Cardiovascular Adverse Event. We found 1,900 (17.70%) patients in trials with aspirin, 5,326 (49.61%) in those with thienopyridines, 2,324 (21.65%) in those with picotamide and 1,185 (11.04 %) in those with others antiplatelet drugs. A statistically significant effect of antiplatelet treatment [odds ratio (OR) 0.839; 95% confidence interval (CI) 0.729–0.965; p=0.014] was observed. There was a statistically significant reduction of clinical outcome [OR 0.779; 95% CI 0.639–0.950; p=0.014] in the thienopyridine-treated group vs. control. Patients treated with picotamide [OR 0.785; 95% CI 0.495–1.243; p=0.302] or aspirin [OR 0.847; 95%CI 0.653–1.097; p=0.084] showed reduced cardiovascular outcomes, that, however, did not reach significance. The study confirms that anti-platelet treatment reduces vascular outcome in claudicants. Significant reduction was observed with thienopyridines while data regarding aspirin and picotamide were inconclusive.

ObjectivesThe aim of this study was to evaluate whether thromboxane inhibition can favorably affect renal perfusion and clinical conditions in patients affected by severe heart failure.BackgroundThe renal formation of the vasoconstrictor thromboxane A2(TxA2) is increased during cardiac failure.MethodsBy oral administration of picotamide (a renal TxA2synthase and TxA2/prostaglandin H2receptor inhibitor), we blocked renal TxA2. Fourteen patients in New York Heart Association functional class IV were studied according to a randomized, double-blinded, cross-over design. Each of the two eight-day periods of testing was preceded by a three-day period during which certain vasoactive medications were stopped.ResultsDaily 24-h total urinary thromboxane B2(TxB2), the stable metabolite of TxA2, dropped at the end of picotamide treatment (p < 0.01 vs. baseline). Compared with placebo, effective renal plasma flow and the glomerular filtration rate increased (p < 0.01 and p < 0.05, respectively), thus leading to a significant decrease in the filtration fraction (p < 0.01). Renal vascular resistance decreased consistently (p < 0.01). In all patients, picotamide treatment was associated with an increase in diuresis and natriuresis (p < 0.001 vs. baseline). Plasma creatinine decreased (p < 0.05 vs. baseline). Patients also showed improvement in several clinical parameters, including a significant decrease in both pulmonary and venous pressure (p < 0.01 vs. baseline).ConclusionsThese results indicate that renal thromboxane formation plays an important role in renal vascular resistance in patients with severe heart failure, such as those described in the present study. Inhibition of TxA2improves renal hemodynamics and kidney function and favorably affects indexes of cardiac performance.

Patients with chronic myeloproliferative disease are at increased risk of both thromboembolic and haemorrhagic complications. Cerebral thrombosis is a common cause of death in myeloproliferative disease patients. Picotamide is a new anti-platelet drug sharing a dual anti-thromboxane activity: inhibition of thromboxane A2 synthase and thromboxane A2 receptor antagonism. Picotamide inhibits in vitro and ex vivo platelet aggregation induced by different agonists. Interestingly, in vitro studies show that picotamide is able to increase prostacycline biosynthesis. In the clinical setting, picotamide treatment induces only a slight prolongation of bleeding time. The safety and efficacy of picotamide long-term treatment in 15 patients with essential thrombocytosis and a positive history of previous thromboembolic events was evaluated. After 12-month treatment with picotamide no patients suffered from thrombotic events and only one minor and transient bleeding episode was observed. This observational long-term trial shows that picotamide treatment in patients with thrombocytosis at high risk of thrombotic events is safe and well tolerated. Picotamide did not increase the risk of bleeding in these patients, while at the same time, no thrombotic events were observed during the 1-year treatment.

Bleeding and thrombosis are major causes of morbidity and mortality in patients with chronic myeloproliferative disorders. We retrospectively evaluated 101 consecutive patients affected by primary thrombocytosis (46 male, 55 female, aged 18-84 years; mean +/- SD 61 +/- 15) followed for a period ranging from 6 months up to 10 years (median 5 years) at our hematological unit. At the time of diagnosis 48 patients were asymptomatic; 26 had clinical evidence of atherothrombosis (cerebral ischemic attacks, ischemic heart disease, peripheral occlusive arterial disease), ten had venous thrombosis, four experienced major hemorrhages, 23 presented microvascular ischemic manifestations namely erythromelalgia, paresthesias, acrocyanosis and dizziness. At presentation 51.2% of the patients had elevated serum lactic dehydrogenase, 34.5% hyperuricemia, and 23.4% serum creatinine > 1.2 mg/dL. Color Doppler ultrasound provided evidence of vascular stenosis or medium-intimal hyperplasia of epiaortic vessels in 48.9% of patients studied, and similar alterations of lower limb arteries in 23.8% of cases. Therapy modality included an antiplatelet agent (picotamide 300 mg/bid); a cytoreductive agent (busulphan, hydroxyurea, pipobroman or melphalan) was used when platelet count was > 800000/microL. Symptoms due to microvascular ischemia promptly regressed after picotamide and cytoreductive therapy. During follow-up. nine patients suffered from atherothrombotic events (transient ischemic attacks, ischemic stroke, unstable angina pectoris) and five developed deep vein thrombosis or superficial thrombophlebitis. Five patients experienced major hemorrhages (two melena, two hematuria, one perioperative bleeding); the two gastrointestinal hemorrhages occurred in patients self-medicated with non steroidal anti-inflammatory drugs, and the two episodes of hematuria occurred on oral anticoagulant therapy and aspirin respectively. No major bleeding occurred in patients on continuative therapy with picotamide, even in the presence of upper digestive tract disorders. Seven patients died: mortality resulted from one sudden coronary death, three solid neoplasia, one blast crisis, one anile, and one massive hemorrhage due to abdominal aortic prosthesis tearing. Our study suggests that a long-term antithrombotic prophylaxis with picotamide may be of benefit in patients affected by primary thrombocytosis; a controlled clinical trial is warranted to assess whether picotamide can ameliorate the natural history of the disease.

1. Picotamide was shown to inhibit platelet binding of thromboxane A2 (TxA2)-mimetics and to cause a reduction of TxA2 platelet receptors after in vivo administration. The present study aimed to investigate directly [3H]-picotamide binding to human platelets and in particular the relationship between binding kinetics and antiaggregating properties. 2. [3H]-picotamide time-dependently bound to a single class of platelet TxA2 receptors with a KD of 325 nmol l-1 at equilibrium. The binding was displaceable by TxA2 analogues U46619 and ONO11120 (Ki 19 and 28 nmol l-1 respectively) but not by prostacyclin (PGI2), prostaglandin E2 (PGE2) and TxB2. Antiaggregating activity and TxA2 formation inhibition paralleled with binding kinetics. 3. By prolonging the incubation time from 30 to 120 min, picotamide showed a progressively increasing non-displaceable binding, whereas specific displaceable binding decreased in comparison to the values reached at 30 min. Non displaceable binding was specific, temperature-dependent saturable and followed a Michaelis-Menten kinetic (Vmaxapp = 130 fmol per 10(8) platelets h-1, KMapp = 330 nmol l-1). Picotamide progressively underwent a specific stable interaction with its platelet receptor. 4. In conclusion, after an initial reversible binding, a progressive stabilization of picotamide binding takes place resulting in a progressively more stable interaction with platelets.

BACKGROUND Patients with peripheral vascular disease (PVD) undergo a clinical course that can be complicated by cardiovascular events occurring in several areas of the circulation. METHODS AND RESULTS In the present study we investigated the ability of picotamide, a substance that inhibits platelet thromboxane A2 (TxA2) synthase and antagonizes TxA2 receptors, to reduce cardiovascular complications in PVD patients. The study was double blind and placebo controlled. After a 1-month run-in period, 2,304 patients were randomly allocated to either placebo or picotamide (300 mg t.i.d.) and followed for 18 months. Major and minor events were analyzed. Results of an "intention-to-treat analysis" were that patients on picotamide suffered 45 major events (3.9%) and 77 minor events (6.7%), whereas those taking placebo suffered 52 major (4.5%) and 99 minor events (8.6%). There was borderline statistical difference between the two groups with respect to the sum of the major and minor events (risk reduction, 18.9%; p = 0.056, log-rank test). Results of an "on-treatment" analysis were that patients on picotamide suffered 40 major (3.8%) and 66 minor events (6.3%), whereas those taking placebo suffered 45 major (4.2%) and 95 minor events (8.9%). The sum of both major and minor events was 106 (10.1%) in the picotamide group and 140 (13.1%) in the placebo group. This difference was significant (risk reduction, 23%; p = 0.029, log-rank test). CONCLUSIONS The results of this study indicate that picotamide reduces cardiovascular complications in PVD patients. The apparently low effect of this drug in reducing major events suggests that further studies be made with picotamide in PVD patients who are at high risk of cardiovascular complications so as to further assess its clinical efficacy.

We investigated the short-term effect of the TXB inhibitor picotamide on albuminuria induced by exercise in 15 microalbuminuric (i.e., with UAE at rest between 20 and 200 μg/min) type II diabetic patients (12 men and 3 women, age 56 ± 2, BMI 28 ± 1 kg/m2) and in six normal age-matched control subjects. The diabetic subjects performed five submaximal exercise tests (90% of theoretical heart rate) on a cycle ergometer: the first two under basal conditions; the third and fifth after subjects had received picotamide (900 mg/day) or placebo (3 tablets/day) for 10 days; the fourth exercise always was performed after 10 days of wash-out. Control subjects performed two exercises: the first in baseline conditions and the second after 10 days of picotamide administration (900 mg/day). When diabetic patients were untreated, a significant (P < 0.05) increase in UAE with respect to baseline levels was observed immediately after and 1 h after the exercise test. After picotamide administration, UAE significantly decreased (P < 0.05) immediately after and 1 h after exercise, as compared with diabetic patients given a placebo. In normal subjects, exercise was followed by a slight increase in UAE, which was not significantly affected by picotamide administration. Our results show that short-term administration of picotamide is associated with a reduction in UAE after exercise in type II diabetes patients with microalbuminuria while at rest. Picotamide, a TXB synthetase and receptor inhibitor, may decrease exercise-induced albuminuria in diabetic patients through a reduction in circulating TXB levels andinhibition of TXB action, which in turn may act by lowering glomerular capillary hydraulic pressure.

The present study was designed to evaluate the usefulness of laboratory monitoring of antiplatelet therapy by means of a multiparametric evaluation of in vitro platelet aggregation tests in the attempt to individually optimize a given therapeutic regimen. The presence of a condition of hyperaggregability was shown in approximately 80% of patients with different forms of athero-sclerotic vascular disease not undergoing any therapeutic regimen with antiplatelet agents. Conversely, a significant decrease in platelet activity was observed in patients undergoing different therapies based on acetylsalicylic acid (ASA), ticlopidine, or indobufen. The similar antiaggregatory effect of low-dose vs. high-dose ASA therapies was also shown. Dipyridamole alone showed no antiaggregatory effect, which, in turn, was reached only by the addition of ASA. Nevertheless, the association of ASA plus dipyridamole did not show any stronger antiplatelet effect than ASA alone. The evaluation of in vitro platelet activity in a group of patients treated with picotamide failed to show any significant change in comparison with the untreated group, probably due to the short half-life of picotamidein man and/or to its capability of reversibly antagonizing the action of thromboxane at receptor level. The evaluation of a long-term follow-up of 90 patients treated with different antiplatelet agents supports the idea that a multiparametric analysis of in vitro platelet aggregation may provide valuable help in monitoring and optimizing a given therapeutic regimen. © 1992 Wiley-Liss, Inc.

1. Picotamide has been shown to interfere competitively with the thromboxane A2 (TxA2) platelet receptor. In the present study the effect of in vivo administration of picotamide on TxA2 human platelet receptors was investigated in 10 healthy subjects. 2. Picotamide (300 mg x 3 daily) or placebo were administered in a double-blind, cross-over, placebo controlled study, each treatment lasting 1 week with a 2 week interval period. TxA2 receptors were investigated by a direct radioligand binding assay method employing [125I]-PTA-OH as labelled ligand. Platelet studies were performed on the first day of treatment immediately before and 2, 4 and 8 h after the ingestion of the drug. The effects of chronic administration were assessed on the seventh day. 3. Two and 4 h after the administration of picotamide 300 mg orally platelet TxA2 receptors were significantly reduced from 1366 +/- 237 to 957 +/- 221 (P less than 0.05) and 753 +/- 119 receptors/platelet (mean +/- s.d.) (P less than 0.03). After 8 h platelet receptor population was restored (1362 +/- 324, NS). The same pattern was observed after 7 days of treatment. Thus picotamide seems to induce a short lasting down regulation of platelet TxA2 receptors.

SummaryEffects of picotamide (900 mg in 3 oral administrations for 7 days) on ex vivo and in vivo platelet T×A2 production and on platelet aggregation wpre evaluated in 8 patients with peripheral arteriopathy and in 8 normal subjects. Picotamide significantly reduced ADP-induced platelet aggregation, but had no effect on that induced by arachidonic acid or the thromboxane analogue U46619. Though ex vivo platelet T×A2 production (T×B2 concentration after arachidonic-acid-induced aggregation) was reduced from 946 ± 141 (mean ± SD) to 285 ± 91 ng/ml in controls and from 1515 ± 673 to 732 ± 420 ng/ml in patients with arteriopathy, there was no effect on urinary excretion of 2,3-dinor-T×B2 (in vivo indicator of platelet T×A2 production), or on in vivo PGI2 production (urinary excretion of 6-keto-PGF1α and 2,3-dinor-6-keto-PGF1α). In the same subjects, single-dose aspirin reduced ex vivo T×B2 production by at least 98% and 2,3-dinor-T×B2 excretion from 116.7 ± 61.4 to 32.6 ± 17.0 nglg creatinine in control subjects, and from 156.3 ± 66.1 to 59.1 ± 19.2 ng/g creatinine in patients with peripheral arteriopathy. Our data suggest that inhibition of platelet T×A2 production in vivo may not be picotamide’s main mechanism of action.

Source Citation Neri Serneri GG, Coccheri S, Marubini E, Violi F. Picotamide, a combined inhibitor of thromboxane A2 synthase and receptor, reduces 2-year mortality in diabetics with peripheral art...

Heparin (Hep) has been shown to be the first-line antithrombotic treatment in unstable angina, thus confirming that thrombin is a potent mediator of thrombus formation on deep vascular injury. Whether aspirin treatment may further add on the effects of heparin is controversial. To further elucidate the role of thrombin and thromboxane A2 in this context, we investigated the effects of Hep at low (0.2–0.4 U/ml; Hep-L) and high (0.5–1.0 U/ml; Hep-H) concentrations and of Hep-L in presence of dual thromboxane inhibition/thromboxane A2 receptor antagonism after the oral ingestion of Picotamide (PIC; 600 mg) in humans. We used a flow system allowing for native human blood to be exposed for 5 min to mild or deep vascular injury on porcine arterial segments. 11l-ln-labelled platelet deposition (PO × 10 6 / cm 2 ) was quantified on arterial segments in cylindrical (Badimon) flow chambers under low (212 s-l) and high (1690 -1 ) shear rate at 37°C. PIC bioavailability was checked by measuring thromboxane B 2 synthesis by clotting human blood. Results (SEM): Hep-L Hep-H p Hep-L + PIC P Mild injury (212 s -1 ) 1.6 (0.4) 0.6 (0.3) * 07 (0.2) * Mild injury (1690 s -l ) 3.9 (1.0) 2.2 (0.5) * 1.8 (0.4) * Deep injury (1690 s -1 ) 12.4 (2.8) 8.2 (2.0) § 6.8 (1.4) § * p l 0.05, § p l 0.01 vs Hep-Loc Thus, thrombin is a strong mediator of thrombosis under flow conditions and requires high Hep levels. However a similar antithrombotic effect may be achieved by the combination of thromboxane A 2 blockade at the receptor level with low Hep levels.

Tumor necrosis factor (TNF) induces hepatitis when injected in human beings or in rodents. The molecular mechanism by which TNF induces hepatic distress remains largely unknown, although induction of apoptosis of hepatocytes appears to be an essential step. In order to increase the therapeutic value of TNF, we have studied the protective activity of several molecules and found that four chemically totally different substances confer significant protection in the model of TNF-induced lethal hepatitis in mice sensitized with D -(+)-galactosamine (GalN), but not in mice sensitized with actinomycin- D (ActD) or against anti-Fas-induced lethal hepatitis. Verapamil, a calcium-channel blocker, tannic acid, picotamide, a thromboxane A 2 receptor antagonist, and K76COOH, an inhibitor, amongst others, of complement, protected significantly against induction of lethality, release of the liver-specific enzyme alanine aminotransferase (ALT) and induction of apoptosis in the liver after TNF/GalN, except for K76COOH, which paradoxically increased ALT values after challenge, and which also protected against TNF/GalN in complement-deficient mice. The data suggest that activation of platelets and neutrophils, as well as induction of inflammation occur in the TNF/GalN model, but not in the TNF/ActD or anti-Fas models, in which direct induction of apoptosis of hepatocytes may be more relevant. The protective activity of the drugs may lead to an increase in therapeutic value of TNF.

On the basis of indirect pharmacological evidence, picotamide, a methoxy derivative of 4-hydroxy-isophthalic acid (N,N′bis(3-picolyl)-4-methoxy-isophthalamide) has been postulated to inhibit platelet aggregation by competitively interfering with the thromboxane A 2 (TxA 2 ) platelet receptor. In the present study the interaction between picotamide and TxA 2 receptors on human platelets was investigated by a direct radioligand assay method with [ 125 I]PTA-OH and [ 3 H]U46619 as labelled radioligands. The ONO11120 and U46619 inhibitory constants (K i ) for [ 125 I]PTA-OH binding were 19 ± 4 and 17 ± 3 nM, respectively. Picotamide displaced [ 125 I]PTA-OH binding with a K i of 1472 ± 321 nM. The K i for ONO 11120 and U46619 on [ 3 H]U46619 binding were 42 ± 12 and 16 ± 5 nM, respectively, whereas the K i for picotamide was 1648 ± 431 nM. These data provide evidence that picotamide can directly inhibit the TxA 2 platelet receptor.

The effect of picotamide on platelet function has been studied in vitro and ex vivo. Picotamide at micromolar concentrations inhibited platelet aggregation induced by ADP, arachidonic acid and collagen, and it also inhibited the production of thromboxane A2 (TxA2). Unlike aspirin, picotamide did not affect the synthesis of prostacyclin by blood vessels. In eight healthy subjects who took picotamide 1200 mg/d platelet aggregation and TxA2 production were inhibited. Picotamide appears to be an antiplatelet drug that reduces TxA2 synthesis without affecting cyclo-oxygenase activity.

Picotamide is a thromboxane A2 (TXA2 ) receptor antagonist and TXA2 synthase inhibitor. In clinical studies, it has been considered as a platelet aggregation inhibitor and improved renal function. In vitro studies suggested inhibition of smooth muscle contraction by picotamide, which is poorly understood. Here, we examined effects of picotamide on contractions of renal interlobar and coronary porcine arteries, induced by different vasoconstrictors. Contractions were induced in an organ bath by agonists or electric field stimulation (EFS). Picotamide inhibited EFS-induced contractions of interlobar arteries around 50% using concentrations of 100 and 300 µM. In interlobar arteries, concentration response curves for contractions induced by three different α1 -adrenoceptor agonists were shifted to the right by picotamide (2-10-fold increases in EC50 ). In coronary arteries, α1 -adrenergic contractions were inhibited without right shift (approx. 50%). Contractions induced by two different cholinergic agonists in coronary arteries were inhibited by picotamide (≥50%) withouth right shift. Inhibition of serotonin-induced contractions by picotamide showed features of a right shift, whereas contractions induced by the TXA2 analog U46619, angiotensin-II, and endothelin-1 were inhibited by picotamide in interlobar and coronary arteries without right shifts and to different degree. Picotamide inhibits a wide spectrum of vasoconstrictor-induced contractions in porcine interlobar and coronary arteries. Inhibition of vasocontraction may contribute to beneficial effects of picotamide in the cardiovascular system and kidney.

Prospective studies have shown that high plasma levels of fibrinogen are independently associated with the risk of cardiovascular complications. In patients suffering from peripheral vascular disease (PVD) fibrinogen has been shown to be an independent predictor of cardiovascular disease but its determinants have never been examined in this clinical setting.Fibrinogen levels were related to clinical and laboratory variables in 2,111 patients suffering from PVD. We also analyzed whether there was a regional distribution of risk factors.The median values of fibrinogen was 312 mg/dL. The clinical variables examined did not differentiate patients with elevated or normal fibrinogen levels. In particular, patients with ankle/arm pressure ratio0.8 did not show a higher prevalence of fibrinogen312 mg/dL. Conversely, white blood cell (WBC) count and serum cholesterol levels were significantly associated with high fibrinogen levels (p0.0001). Multiple logistic regression analysis demonstrated that areas of Italy were differently associated with high plasma fibrinogen levels (p0.03): subjects in the north and middle of Italy having significantly higher values of fibrinogen than subjects in the south of Italy (p0.01). A similar regional distribution was observed for WBC count and serum cholesterol levels.The regional distribution of risk factors raises the question as to whether the already reported large variability of cardiovascular events so in PVD may be attributed to a non homogeneous distribution of risk factors.

Picotamide is an antiplatelet drug which inhibits thromboxane A2 (TxA2) synthase and antagonizes TxA2 receptors. In the ADEP (Atherosclerotic Disease Evolution by Picotamide) trial, 2304 patients with peripheral obstructive arterial disease (POAD) were studied in a double-blind, placebo-controlled, 18-month, multicentre trial. In this study, 151 events (13.1%) occurred on placebo and 122 (10.6%) on picotamide (900 mg day-1). The relative risk reduction was 19%, (P = 0.056). This paper reports a post-hoc analysis in a subgroup of 438 diabetic patients (picotamide = 230; placebo = 208). There were 32 vascular events on placebo (15%) and 18 on picotamide (8%) (relative risk reduction: 48%; 95% CI = 26, 76; P = 0.022). The results of this retrospective analysis suggest that a prospective study to investigate events in claudicant patients with diabetes mellitus is warranted.

The goal of this paper is to provide an updated review for scientists and clinicians on the major areas in cardiovascular medicine published in the Journal. Leading topics in regenerative and personalized medicine are presented along with a critical overview of the field. New standards in large preclinical animal models of pulmonary hypertension and left bundle branch block are highlighted. Finally, clinical care in the areas of atherosclerosis, the aortic valve, platelet biology, and myocarditis is discussed as well as autonomic modulation therapies. © 2015, Springer Science+Business Media New York.

In the A.D.E.P (Atherosclerotic Disease Evolution by Picotamide) study 2,304 patients with peripheral obstructive arterial disease (POAD) were recruited for a double blind 18-month multi-centre trial comparing picotamide (300 mg t.i.d.), an antiplatelet drug which inhibits thromboxane A2 (TxA2) synthase and antagonizes TxA2 receptor, and placebo. In the study population as a whole, 151 events (13.1%) occurred on placebo and 122 (10.6%) on picotamide, with a relative risk reduction of 19%, (p = 0.056, Logrank test, intention to treat analysis). The effect of picotamide was assessed in the A.D.E.P subgroup of diabetic patients, in order to test if the drug was still effective in patients at higher risk of cardiovascular complications. Diabetic patients were 438 (230 on picotamide and 208 on placebo). Most of them were male (80%), with a mean age of 64 years (min 40, max 75). Six per cent were insulin-dependent. The main risk factors (smoking, hypertension, previous vascular surgery, ankle/arm pressure ratio, WBC count and fibrinogen) were similarly distributed in the two groups. Diabetic POAD patients on placebo suffered from a total of 33 cardiovascular events (12 major and 21 minor) (15.9%), whereas those on picotamide suffered from a total of 20 events (6 major and 14 minor) (8.7%) (relative reduction of risk: 45.2%, p = 0.022 at Logrank test, intention to treat analysis). Both major and minor events occurred more frequently in the placebo than in the picotamide group. The overall incidence of major events was 5.8% on placebo and 2.6% on picotamide (relative risk reduction of 59.8%). Death occurred in 6 patients on placebo (2.9%) and in 3 on picotamide (1.3%). Non fatal major events (stroke, myocardial infarction and amputation) were 6 on placebo and 3 on picotamide. Minor events were 10.1% on placebo and 6.1% on picotamide (relative risk reduction of 39.8%). Adverse reaction, mainly gastrointestinal, occurred in 16% of patients, regardless of the treatment. In conclusion, this analysis indicates that Picotamide significantly reduces cardiovascular events in diabetic POAD patients, suggesting its potential use in patients at high risk of atherosclerotic progression.