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The influence of misoprostol (synthetic analogue of prostaglandin E1) on aspirin-induced bronchoconstriction in aspirin-sensitive asthma.

It is believed that aspirin (ASA) and other nonsteroidal anti-inflammatory drugs elicit dyspnea in ASA-sensitive asthmatics by blocking cyclooxygenase. It is unclear whether this bronchospasm is due to the shunting of arachidonic acid into the lipoxygenase pathway or to the removal of a cyclooxygenase product which prevents bronchospasm. Diminished tissue concentration of PGE may cause bronchoconstriction. PGE also modulates mast cells, decreasing the release of anaphylaxis mediators. The authors investigated the influence of a synthetic analogue of PGE1-misoprostol (Cytotec, Searle)-on post-aspirin bronchoconstriction in seven ASA-sensitive asthmatics. On the first day, the effect of a placebo was studied. On the second day, the bronchodilatory effect of misoprostol (Cytotec, Searle) alone was examined. After a few days, a predetermined threshold dose of ASA was administered. Seven days later, at least 400 micrograms of misoprostol +200 micrograms 2 h later, together with a predetermined ASA dose, were administered. In all but one patient, the protective influence of misoprostol on ASA-induced bronchoconstriction was observed. The maximum drop in FEV1 (forced expiratory volume in one second) in % after ASA in each of the patients was 40, 25, 24, 33, 47 and 54, and after ASA with misoprostol 10, 9, 4, (+8), 10, (+2) and 45, respectively. Misoprostol given together with ASA attenuated aspirin-induced bronchoconstriction, reaching statistical significance at 3 and 3.5 h. It also diminished extrapulmonary symptoms.

Adult↗

Prolonged bleeding times after aspirin ingestion in patients with aspirin idiosyncrasy.

Measurements of the bleeding time after the ingestion of small doses of aspirin in patients with aspirin idiosyncrasy demonstrate a marked prolongation compared with control patients. Confirmation of this finding offers a clue to the pathogenesis of this condition. Despite the prolonged bleeding time, gastrointestinal haemorrhage is an uncommon event in patients with aspirin idiosyncrasy.

Adult↗

Semi-micro column high-performance liquid chromatography with UV detection for quantification of aspirin and salicylic acid and its application to patients' sera administered with low-dose enteric-coated aspirin.

A simultaneous determination of aspirin (ASA) and its metabolite, salicylic acid (SA), in human serum by a semi-micro column HPLC-UV was developed. A relatively small size of serum sample (100 microL) containing ASA and SA was cleaned up by a simple solid phase extraction. A good separation of ASA and SA could be achieved within 25 min using a semi-micro ODS column with an eluent of MeOH/0.7 mm phosphoric acid solution (pH 2.5) = 50:50 (v/v). The calibration curves for ASA and SA showed good linearity (r = 0.999) with the detection limits 114 and 38 ng/mL at a signal-to-noise ratio of 3, respectively. ASA and SA in patients' sera administered with low-dose enteric-coated aspirin were determined, and the concentration ranges obtained for ASA and SA were 1.2-2.2 and 0.5-57.3 microg/mL, respectively.

Aged↗

Comparative study of policosanol, aspirin and the combination therapy policosanol-aspirin on platelet aggregation in healthy volunteers.

A randomized, double-blind, placebo-controlled study was conducted in 43 healthy volunteers to compare the effects of policosanol (20 mg day-1), aspirin (ASA) (100 mg day-1) and combination therapy (policosanol 20 mg day-1 plus ASA 100 mg day-1) on platelet aggregation. The healthy volunteers were randomly treated for 7 days. Both, platelet aggregation and coagulation time were measured at baseline and after therapy. When policosanol was administered platelet aggregation induced by ADP (37.3%), epinephrine (32.6%) and collagen (40.5%) were significantly reduced. Meanwhile, aspirin significantly reduced platelet aggregation induced by collagen (61.4%) and epinephrine (21.9%) but not ADP-induced aggregation. Combined therapy significantly inhibited aggregation induced by all the agonists reaching the highest reductions of platelet aggregation induced by collagen (71.3%) and epinephrine (57.5%). Coagulation time did not change significantly in any group. No subject withdrew from the trial. Four volunteers reported mild adverse experiences during the study: three ASA-treated cases referred headache, epigastralgia and nose bleeding, meanwhile one patient receiving combination therapy reported gum bleeding. The present results demonstrate that policosanol (20 mg day-1) is as effective as ASA (100 mg day-1). Moreover, combination therapy shows some advantages compared with the respective monotherapies.

Adult↗

Increased protein glycation in diabetes mellitus is associated with decreased aspirin-mediated protein acetylation and reduced sensitivity of blood platelets to aspirin.

Reduced effectiveness of the most common antiplatelet drug, acetylsalicylic acid (ASA, aspirin), in diabetes mellitus has been associated with a lowered platelet sensitivity to ASA and related to glycemic control in diabetic patients. Our objectives were (a) to monitor the chemical background of how chronic hyperglycemia affects platelet response to ASA in diabetes and (b) to study a chemical competition between the amount of bound acetyl residues and the extent of protein glycation in blood platelets. Using whole-blood impedance aggregometry and platelet function analyzer (PFA-100) we observed a reduced platelet response to ASA in diabetic patients (14% vs. 79% for PFA-100 collagen-epinephrine occlusion time) and an association between the index of glycemic control and platelet refractoriness to ASA (r(S) = -0.378). Impaired platelet response to ASA was related to enhanced platelet protein glycation (3.6+/-0.4 in diabetes vs. 2.3+/-0.4 micromol fructosamine/microg protein in control) and reduced incorporation of acetyl residue into proteins of platelets from diabetic patients (47.4+/-2.0 in control vs. 33.1+/-0.7 micromol acetyl/microg protein in diabetic subjects). Incubation of blood platelets with increasing concentrations of glucose and ASA under in vitro conditions led to excessive modification in protein amino groups: glucose and ASA competed with each other in the course of nonenzymatic modifications, glycosylation, or acetylation, and their contributions to the occupancy of protein amino groups (R2 = 0.22 for glucose, R2 = 0.43 for ASA) were dependent upon the concentrations of glucose and ASA. Overall the effects of high glucose and high ASA on the overall occupancy of protein free amino groups are not additive. While at higher concentrations ASA overcomes the effects of hyperglycemia and retards glycation, high glucose makes acetylation less efficient, and therefore the resultant chemical modification becomes greatly reduced. In conclusion, diminished susceptibility of various platelet proteins and receptors on blood platelet membranes to acetylation and high ambient glucose might underlie the apparently differentiated sensitivity of blood platelets to ASA and determine platelet "insensitivity to aspirin" in diabetic patients.

Acetylation↗

Eptifibatide provides additional platelet inhibition in non-ST-elevation myocardial infarction patients already treated with aspirin and clopidogrel. Results of the platelet activity extinction in non-Q-wave myocardial infarction with aspirin, clopidogrel, and eptifibatide (PEACE) study.

OBJECTIVES: The present study hypothesis was that eptifibatide offered further antiplatelet efficacy above clopidogrel in non-ST-elevation myocardial infarction (NSTEMI) patients before an expeditive coronary intervention. BACKGROUND: Although thienopyridines and glycoprotein (GP) IIb/IIIa antagonists are often co-prescribed in the context of NSTEMI, the antiplatelet interaction of these agents is poorly described and the superiority of GP IIb/IIIa antagonists above thienopyridine treatment alone is not clear. METHOD: Thirty-two NSTEMI patients treated with aspirin and enoxaparin were studied using flow cytometry to define parameters of platelet activation with a panel of agonists before clopidogrel, after clopidogrel, and during an eptifibatide infusion following the clopidogrel load. RESULTS: After platelet activation with adenosine diphosphate, thrombin receptor-activating peptide, or U46-619, relative reductions in conformationally activated GP IIb/IIIa receptor expression (evaluated with PAC-1) of 48%, 43%, and 33%, respectively (all p < 0.0001), were seen with clopidogrel, but further 80%, 78%, and 72% (all p < 0.0001) reductions were seen with eptifibatide. With the same agonists, fibrinogen binding was significantly reduced after clopidogrel by 70%, 64%, and 81% (all p < 0.0001) and again further reduced with eptifibatide by 90%, 95%, and 69% (all p < 0.0001). The total number of GP IIb/IIIa receptors (measured as P2 expression) and P-selectin expression fell after clopidogrel, after ex vivo stimulation with the same agonists; however, both parameters increased slightly during the eptifibatide infusion. CONCLUSIONS: The activated GP IIb/IIIa expression and fibrinogen binding findings indicate that eptifibatide provides significant potent antiplatelet activity above aspirin and clopidogrel, suggesting additive immediate protection in the treatment of NSTEMI. The P2 and P-selectin findings suggest the possibility of a partial agonist and/or pro-inflammatory effect.

Aged↗

Dynamics of COX-2 in nasal mucosa and nasal polyps from aspirin-tolerant and aspirin-intolerant patients with asthma.

BACKGROUND: Only dynamic studies can elucidate the discrepancies concerning the expression of the inducible COX-2 gene in inflammatory airway diseases. OBJECTIVES: To quantify the expression and spontaneous regulation of COX-1 and COX-2 mRNAs in nasal polyps and nasal mucosa by real-time PCR. METHODS: Nasal polyps were obtained from 16 aspirin-tolerant patients with asthma/rhinitis (ATAR) and 18 aspirin-intolerant patients with asthma/rhinitis (AIAR) undergoing nasal polypectomy. Nasal mucosa was obtained from 12 subjects undergoing nasal corrective surgery. All specimens were cut into 3 pieces. One was immediately snap-frozen in liquid nitrogen, and the remaining 2 were left at room temperature for 30 or 60 minutes before freezing. Data are presented as medians and 25th to 75th percentiles of 10 6 cDNA molecules/microg total RNA. RESULTS: Baseline COX-2 mRNA levels were significantly lower in both ATAR (0.45; 0.13-1.20; P <.05) and AIAR (0.24; 0.12-0.41; P <.001) nasal polyps than in nasal mucosa (1.35; 0.52-3.90). COX-2 mRNA expression did not change over time in nasal mucosa but increased significantly in ATAR nasal polyps ( P <.05), reaching similar levels to nasal mucosa after 60 minutes. In contrast, COX-2 mRNA showed no significant change over time in AIAR nasal polyps. COX-1 mRNA was higher in nasal polyps than in nasal mucosa, and its expression was not modified over time in any group of patients. CONCLUSION: These results suggest differential kinetics of COX-2 mRNA between nasal mucosa and nasal polyps. AIAR nasal polyps appear to have a greater abnormality of the COX-2 pathway than ATAR.

Adult↗

Effects of clopidogrel and aspirin combination versus aspirin alone on platelet aggregation and major receptor expression in patients with heart failure: the Plavix Use for Treatment Of Congestive Heart Failure (PLUTO-CHF) trial.

BACKGROUND: Persistent platelet activation may contribute to thrombotic events in patients with congestive heart failure (CHF). Chronic use of mild platelet inhibitors could therefore represent an independent avenue to improve morbidity, mortality, and quality of life in this expanding population. Although clopidogrel is widely used in patients with acute coronary syndromes and ischemic stroke, the ability of this novel ADP-receptor antagonist to inhibit platelet function in patients with CHF is unknown. We assessed antiplatelet properties of clopidogrel with aspirin (C+A) versus aspirin alone (A) in patients with CHF with heightened platelet activity. METHODS: Patients with left ventricular ejection fraction <40%, or CHF symptoms in the setting of preserved systolic function and New York Heart Association class II-IV were screened. Patients were considered to have platelet activation when 4 of the following 5 parameters were met: ADP-induced platelet aggregation >60%; collagen-induced aggregation >70%; whole blood aggregation >18 ohms; expression of GP IIb/IIIa >220 log MFI; and P-selectin cell positivity >8%. All patients were treated with 325 mg of acetylsalycilic acid (ASA) for at least 1 month. Patients receiving an antithrombotic agent other than ASA were excluded. Patients meeting clinical and laboratory criteria were randomly assigned to C+A (n=25), A (n=25) groups, or represent screen failures (n=38). Platelet studies (conventional and whole blood aggregometry, shear-induced activation, expression of 10 major receptors and formation of platelet-leukocyte microparticles) were performed at baseline and after 30 days of therapy. RESULTS: There were no deaths, hospitalizations, or serious adverse events. There were no changes in platelet parameters in the A group. In contrast, therapy with C+A resulted in a significant inhibition of platelet activity assessed by ADP-induced (P =.00001), and epinephrine-induced (P =.0016) aggregation, closure time (P =.04), expression of PECAM-1 (P =.009), GP Ib (P =.006), GP IIb/IIIa antigen (P =.0001), GP IIb/IIIa activity with PAC-1 (P =.0021), and CD151 (P =.0026) when compared with the A group. Therapy with C+A also resulted in the reduced formation of platelet-leukocyte microparticles (P =.021). Collagen-induced aggregation in plasma and in whole blood, expression of vitronectin receptor, P-selectin, CD63, CD107a, and CD107b did not differ among groups. CONCLUSIONS: Treatment with C+A for 1 month provides significantly greater inhibition of platelet activity than ASA alone in patients with CHF. Patients with CHF with heightened platelet activity represent a potential target population in which addition of clopidogrel may decrease mortality rates by reducing the incidence of thrombotic vascular events.

Aged↗

Combination therapy with aspirin plus clopidogrel versus aspirin plus ticlopidine for prevention of subacute thrombosis after successful native coronary stenting.

We compared the combination of aspirin plus clopidrogrel (A+C) with aspirin and ticlopidine (A+T) for prevention of subacute stent thrombosis in 827 patients. At 30-day follow-up, there were trends toward increased subacute thrombosis with A+C compared with A+T (1.3% vs 0.2%, p = 0.10). These results suggest that A+C may have marginally higher subacute stent thrombosis than A+T.

Aged↗

Design of a placebo-controlled clinical trial of long-acting diltiazem and aspirin versus aspirin alone in patients receiving thrombolysis with a first acute myocardial infarction. Incomplete Infarction Trial of European Research Collaborators Evaluating Prognosis Post-Thrombolysis (diltiazem) (INTERCEPT) Research Group.

Several pharmacologic forms of adjunctive therapy, designed to enhance the efficacy of thrombolysis following acute myocardial infarction (AMI), are being explored. However, few studies have assessed the use of standard secondary prevention therapies (beta-blockers, angiotensin-converting enzyme inhibitors, magnesium, calcium antagonists, etc.) for antecedent thrombolysis. Although calcium antagonists have not been shown to alter post-AMI mortality, diltiazem has been shown to reduce recurrent nonfatal infarction and myocardial ischemia following non-Q-wave AMI. Because both non-Q-wave AMI and AMI treated with thrombolytic therapy result in early reperfusion and clinical manifestations of "incomplete infarction" (i.e., aborted transmural infarction), we hypothesize that prophylactic administration of diltiazem to AMI patients who receive thrombolysis before other therapies might decrease ischemic complications. We have initiated a multicenter, randomized, placebo-controlled, double-blind, parallel-group comparison of long-acting diltiazem 300 mg/day and aspirin 160 mg/day versus aspirin 160 mg/day alone in up to 920 patients with an uncomplicated first AMI (no heart failure or left ventricular dysfunction) within 36 to 96 hours of receiving thrombolysis. Active enrollment is under way at 46 centers in the United Kingdom, Belgium, The Netherlands, and Denmark. This trial (known as the Incomplete INfarction Trial of European Research Collaborators Evaluating Prognosis Post-Thrombolysis [diltiazem], or INTERCEPT) represents the first long-term, large-scale, prospective study of a calcium antagonist administered post-thrombolysis as adjunctive therapy to AMI patients in which the primary trial objective is to assess the effect of blinded therapy on the 6-month cumulative occurrence of a combined clinical end point (cardiac death, recurrent nonfatal AMI, and medically refractory ischemia).

Adolescent↗

Nasal provocation test (NPT) with aspirin: a sensitive and safe method to diagnose aspirin-induced asthma (AIA).

BACKGROUND: We have aimed to determine the sensitivity and specificity of a simpler technique with less risk than oral provocation to diagnose aspirin-induced asthma (AIA). METHODS: We studied a group of 20 AIA patients compared to a control group with 40 aspirin-tolerant patients (confirmed by oral provocation test): 10 asthmatic patients and 30 healthy subjects. A nasal provocation test (NPT) with lysine acetylsalicylic acid (L-ASA) was carried out. Nasal and pulmonary functions were monitored with anterior active rhinomanometry (AAR) and spirometry. An L-ASA solution (900 mg/ml L-ASA, equivalent to 500 mg/ml acetylsalicylic acid) was diluted with saline solution. We administered four increasing doses: 5, 25, 50 and 100 mg/ml acetylsalicylic acid (ASA) with saline solution control. Nasal and pulmonary functions were monitored with rhinomanometry and spirometry. The patients were controlled for nasal inspiratory peak flow and expiratory peak flow. RESULTS: The results showed high sensitivity and specificity: 80% and 92.5%, respectively, with an 84.2% positive predictive value and an 89.2% negative predictive value. The patients had no bronchial or systemic symptoms, and no decreases over 20% were recorded in the FEV1. CONCLUSION: NPT has a high sensitivity and specificity in the diagnosis of AIA. An oral provocation should be performed to confirm the result whenever the clinical situation of the patient permits it.

Adolescent↗

Oral and bronchial provocation tests with aspirin for diagnosis of aspirin-induced asthma.

In 35 asthmatic patients with acetylsalicylic acid (aspirin; ASA) intolerance (AIA) and 15 asthmatics tolerating ASA well, the authors compared the diagnostic value of the placebo-controlled oral ASA versus inhaled L-lysine (L) ASA challenges. All AIA subjects gave a history of asthmatic attacks following ingestion of ASA and in all of them the intolerance was confirmed by oral challenge test over the past 10 yrs. Doses of ASA increasing in geometric progression were used in oral tests 10-312 mg (cumulative dose 500 mg); in bronchial tests 0.18-115 mg (cumulative dose 182 mg). Either challenge was considered as positive, if forced expiratory volume in one second (FEV1) dropped at least 20% from the baseline value and/or strong extrabronchial symptoms of intolerance occurred. Urinary leukotriene E4 excretion was determined at baseline and following the challenges. In 24 out of 35 patients the oral test was positive, based on a 20% decrease in FEV1. When including extrabronchial symptoms this was positive in 31 cases. Bronchial L-ASA challenge led to > or =20% fall FEV1 in 21 out of 35 cases, and in 27 cases when including extrabronchial symptoms. No correlation was observed between ASA provocative dose causing a 20% fall in FEV1, determined by the oral route compared to the inhalation route. Urinary LTE4 increased after both challenges the rise being higher following oral as compared to inhalation provocation (p=0.0001). It is concluded that both tests had similar specificity whilst the oral test showed a tendency to higher sensitivity for the clinical diagnosis of acetylsalicylic acid intolerance. The inclusion of extrabronchial symptoms into the criteria of test positivity enhanced the diagnostic value of both procedures. In both tests the highest leukotriene E4 increases were found in the presence of extrabronchial symptoms, suggesting the participation of tissues other than the lung in aspirin induced leukotriene E4 release to urine.

Adult↗

Release of cysteinyl leukotrienes with aspirin stimulation and the effect of prostaglandin E(2) on this release from peripheral blood leucocytes in aspirin-induced asthmatic patients.

BACKGROUND: The decrease in prostaglandin E(2) (PGE(2)) release due to aspirin (ASA)-induced cyclooxygenase inhibition and the increment in cysteinyl leukotriene (Cys-LT) release secondary to the removal of the inhibitory effect of PGE(2) on Cys-LT release have been suggested in the pathogenesis of aspirin-induced asthma (AIA). OBJECTIVE: In this study, we aimed to investigate the in vitro release of Cys-LT and to determine the effect of PGE(2) on Cys-LT release from peripheral blood leucocytes of patients with AIA after stimulation by ASA. PATIENTS AND METHODS: Patients with AIA (n = 13), patients with ASA-tolerant asthma (ATA) (n = 12) and healthy volunteers as controls (n = 13) were included to the study. ASA and PGE2 at three different concentrations were applied to the peripheral blood leucocytes of the study group, and Cys-LT levels following stimulants were assessed by enzyme immunoassay method. RESULTS: There was no difference in baseline Cys-LT levels between groups (AIA 353.4 +/- 55.5 pg/mL, ATA 354.7 +/- 40.3 pg/mL, and control group 368.5 +/- 30.2 pg/mL; P > 0.05). Though not present in other groups, the Cys-LT level of 453.6 +/- 70.0 pg/mL following ASA stimulation was higher than baseline in patients with AIA (P = 0.04). When PGE(2) was added to the ASA-stimulated samples of patients with AIA, Cys-LT levels were measured as 298.7 +/- 78.6 pg/mL, 279.8 +/- 79.9 pg/mL, and 243.4 +/- 51.3 pg/mL at PGE(2) 10(-7) m, 10(-6) m and 10(-5) m concentrations, respectively. These levels were lower than the ASA-stimulated Cys-LT values (P = 0.03, P = 0.01 and P = 0.01, respectively). The inhibitory effect of different PGE(2) concentrations on Cys-LT release was also present in patients with ATA and in controls. CONCLUSION: The increase in Cys-LT levels following ASA stimulation seems to be unique to AIA, which was not present in patients with ATA and in healthy controls. The inhibitory effect of PGE(2) on stimulated Cys-LT levels is another important finding to elucidate the role of PGE(2) in the pathogenesis of AIA.

Adult↗

Protection against exercise-induced bronchoconstriction by montelukast in aspirin-sensitive and aspirin-tolerant patients with asthma.

BACKGROUND: Montelukast, a cysteinyl-leukotriene receptor antagonist, was reported to have a protective effect against exercise-induced bronchoconstriction (EIB). Aspirin-induced asthma (AIA) is characterized by overproduction of cysteinyl-leukotrienes. OBJECTIVE: The aim of the study was to compare the response to exercise and the effect of montelukast on EIB in AIA as compared to aspirin-tolerant asthma (ATA). METHODS: A placebo-controlled, double blind, cross-over randomized study was performed in 19 AIA and 21 ATA patients with stable asthma. A single dose of montelukast (10 mg) or placebo (PL), was given orally one hour prior to exercise challenge. FEV1 was measured before and 5, 10, 15 min after exercise and then at 15-minute intervals for 4 h. Urinary LTE4 excretion and blood eosinophil count were measured at baseline, 2 h and 4 h following exercise challenge. RESULTS: Positive bronchial response to exercise was observed in 47.5% of all patients studied. Exercise led to almost identical maximal fall in FEV1 in AIA and ATA patients (23.5% +/- 6.8% vs. 21.8% +/- 12.0%, respectively; P = 0.7). Montelukast, as compared to PL, significantly attenuated EIB in 63.2% of 19 patients with positive exercise test preceded by PL. The mean of maximum fall in FEV1 from the pre-exercise value was 10.2% +/- 13.8 after montelukast as compared to 22.5% +/- 10.2 after placebo (P < 0.001). No significant differences between protective effect of montelukast was observed in AIA as compared to ATA patients (P = 0.63, anova). Urinary LTE4 excretion showed no change following exercise, irrespective of the result of the test in all subjects. CONCLUSION: Patients with AIA and ATA react similarly to exercise challenge and obtain similar protection against EIB by montelukast.

Acetates↗

A comparison of aspirin plus tirofiban with aspirin plus heparin for unstable angina.

BACKGROUND: Activation of platelets is central to the pathophysiology of unstable angina. We studied whether inhibition of the final common pathway for platelet aggregation with tirofiban, a nonpeptide glycoprotein IIb/IIIa receptor antagonist, would improve clinical outcome in this condition. METHODS: In a double-blind study, we randomly assigned 3232 patients who were already receiving aspirin to additional treatment with intravenous tirofiban for 48 hours. The primary end point was a composite of death, myocardial infarction, or refractory ischemia at 48 hours. RESULTS: The incidence of the composite end point was 32 percent lower at 48 hours in the group that received tirofiban (3.8 percent, vs. 5.6 percent with heparin; risk ratio, 0.67; 95 percent confidence interval, 0.48 to 0.92; P=0.01). Percutaneous revascularization was performed in 1.9 percent of the patients during the first 48 hours. At 30 days, the frequency of the composite end point (with the addition of readmission for unstable angina) was similar in the two groups (15.9 percent in the tirofiban group vs. 17.1 percent in the heparin group, P=0.34). There was a trend toward a reduction in the rate of death or myocardial infarction with tirofiban (a rate of 5.8 percent, as compared with 7.1 percent in the heparin group; risk ratio, 0.80; 95 percent confidence interval, 0.61 to 1.05; P=0.11), and mortality was 2.3 percent, as compared with 3.6 percent in the heparin group (P=0.02). Major bleeding occurred in 0.4 percent of the patients in both groups. Reversible thrombocytopenia occurred more frequently with tirofiban than with heparin (1.1 percent vs. 0.4 percent, P=0.04). CONCLUSIONS: Tirofiban was generally well tolerated and, as compared with heparin, reduced ischemic events during the 48-hour infusion period, during which revascularization procedures were not performed. The incidence of refractory ischemia and myocardial infarction was not reduced at 30 days, but mortality was lower among the patients given tirofiban. Platelet inhibition with aspirin plus tirofiban may have a role in the management of unstable angina.

Aged↗

Effects of nitric oxide-releasing aspirin versus aspirin on restenosis in hypercholesterolemic mice.

Restenosis is due to neointimal hyperplasia, which occurs in the coronary artery after percutaneous transluminal coronary angioplasty (PTCA). During restenosis, an impairment of nitric oxide (NO)-dependent pathways may occur. Concomitant hypercholesterolemia may exacerbate restenosis in patients undergoing PTCA. Here, we show that a NO-releasing aspirin derivative (NCX-4016) reduces the degree of restenosis after balloon angioplasty in low-density lipoprotein receptor-deficient mice and this effect is associated with reduced vascular smooth muscle cell (VSMC) proliferation and macrophage deposition at the site of injury. Drugs were administered following both therapeutic or preventive protocols. We demonstrate that NCX-4016 is effective both in prevention and treatment of restenosis in the presence of hypercholesterolemia. These data indicate that impairment of NO-dependent mechanisms may be involved in the development of restenosis in hypercholesterolemic mice. Although experimental models of restenosis may not reflect restenosis in humans in all details, we suggest that a NO-releasing aspirin derivative could be an effective drug in reducing restenosis following PTCA, especially in the presence of hypercholesterolemia and/or gastrointestinal damage.

Animals↗

Salicylate pre-treatment attenuates intensity of bronchial and nasal symptoms precipitated by aspirin in aspirin-intolerant patients.

Aspirin (ASA) and other non-steroidal anti-inflammatory drugs, which are cyclooxygenase (COX) inhibitors, precipitate asthmatic attacks in ASA-intolerant patients, while sodium salicylate, hardly active on COX by itself, is well tolerated by these patients. However, salicylate moiety appears to interfere with aspirin inhibitory action on platelets and vascular COX. Such interaction, if present at the level of respiratory tract, may be of interest to pathogenesis of ASA-induced asthma. We performed a double-blind, placebo-controlled, randomized cross-over study on the effect of choline magnesium trisalicylate (CMT, trilisate) pre-treatment on ASA-induced adverse reactions in nine patients. Pulmonary function tests, nasal symptoms score, PNIF and serum salicylate levels were monitored following challenges with threshold doses of ASA. Trilisate administered at a dose of 3000 mg daily for 3 days, offered a moderate protection against ASA-induced symptoms; it diminished the severity and/or delayed the appearance of FEV1 fall. Maximal decreases in FEV1 as well as reaction intensity indexes were significantly lower (P less than 0.02 and P less than 0.002, respectively) after trilisate pre-treatment as compared to placebo. Trilisate also attenuated nasal symptoms in three out of five patients. Although the precise mechanism of the protective action of trilisate is unknown, our data support the possibility of interaction between salicylate and ASA on cyclo-oxygenase locus in the respiratory tract in ASA-intolerant patients.

Adult↗

Minimization of gastric damage with enteric-coated aspirin granules compared to buffered aspirin.

This study involved a randomized parallel groups comparison of the effects of aspirin formulated as enteric-coated granules (25 subjects) or as buffered tablets (26 subjects) with that of a lactose placebo (5 subjects), on the gastric and duodenal mucosa, as determined by endoscopic examination 2 h after a fasting single 975-mg dose. A grading scale of 0 (no damage) to 4 (severe damage) was used. The granule formulation produced a statistically significant (p less than 0.05) lower severity (mean 0.40 +/- 0.58 vs. 3.00 +/- 0.94) and incidence (36% of subjects vs. 100%) of gastric lesions than the buffered aspirin formulation. None of the lesions produced by the granule formulation or the placebo was considered clinically significant by the blinded endoscopist, whereas 17 subjects on the buffered formulation (65%) had clinically meaningful stomach damage. The incidence of duodenal lesions was minimal and comparable for the two formulations.

Adolescent↗