Effect of rebamipide on gastric bleeding and ulcerogenic responses induced by aspirin plus clopidogrel under stimulation of acid secretion in rats.

BACKGROUND AND AIM: We examined the prophylactic effect of rebamipide on gastric bleeding induced by the perfusion of aspirin (acetylsalicylic acid [ASA]) plus clopidogrel under the stimulation of acid secretion in rats. METHODS: Under urethane anesthesia, acid secretion was stimulated by the i.v. infusion of histamine (8 mg/kg/h), and the stomach was perfused with 25 mmol/L ASA at a rate of 0.4 mL/min. Gastric bleeding was evaluated as the concentration of hemoglobin in the perfusate. Clopidogrel (30 mg/kg) was given p.o. 24 h before the perfusion. Rebamipide (3-30 mg/kg) or other antiulcer drugs were given i.d. before the ASA perfusion. RESULTS: Slight gastric bleeding or damage was observed with the perfusion of ASA under the stimulation of acid secretion, whereas these responses were significantly increased in the presence of clopidogrel. Both omeprazole and famotidine inhibited acid secretion and prevented these responses to ASA plus clopidogrel. Rebamipide had no effect on acid secretion, but dose-dependently prevented gastric bleeding in response to ASA plus clopidogrel, with the degree of inhibition being almost equivalent to that of the antisecretory drugs, and the same effects were obtained with the gastroprotective drugs, irsogladine and teprenone. These agents also reduced the severity of gastric lesions, although the effects were less than those of the antisecretory drugs. CONCLUSIONS: These results suggest that the antiplatelet drug, clopidogrel, increases gastric bleeding induced by ASA under the stimulation of acid secretion, and the gastroprotective drug, rebamipide, is effective in preventing the gastric bleeding induced under such conditions, similar to antisecretory drugs.

Comparative effects of the anti-platelet drugs, clopidogrel, ticlopidine, and cilostazol on aspirin-induced gastric bleeding and damage in rats.

AIMS: The present study compared the effects of frequently used anti-platelet drugs, such as clopidogrel, ticlopidine, and cilostazol, on the gastric bleeding and ulcerogenic responses induced by intraluminal perfusion with 25 mM aspirin acidified with 25 mM HCl (acidified ASA) in rats. MAIN METHODS: The stomach was perfused with acidified ASA at a rate of 0.4 ml/min for 60 min under urethane anesthesia, and gastric bleeding was measured as the concentration of hemoglobin in the luminal perfusate, which was collected every 15 min. Clopidogrel (10-100mg/kg), ticlopidine (10-300 mg/kg), or cilostazol (3-30 mg/kg) was given p.o. 24h or 90 min before the perfusion of acidified ASA, respectively. KEY FINDINGS: Perfusion of the stomach with acidified ASA alone led to slight bleeding and lesions in the stomach. The pretreatment with clopidogrel, even though it did not cause bleeding or damage by itself, dose-dependently increased the gastric bleeding and ulcerogenic responses induced by acidified ASA. Ticlopidine also aggravated the severity of damage by increasing gastric bleeding, and the effects of ticlopidine at 300 mg/kg were equivalent to those of clopidogrel at 100mg/kg. In contrast, cilostazol dose-dependently decreased gastric bleeding and damage in response to acidified ASA. SIGNIFICANCE: These results demonstrated that clopidogrel and ticlopidine, P2Y12 receptor inhibitors, increased gastric bleeding and ulcerogenic responses to acidified ASA, to the same extent, while cilostazol, a phosphodiesterase III inhibitor, suppressed these responses. Therefore, cilostazol may be safely used in dual anti-platelet therapy combined with ASA, without increasing the risk of gastric bleeding.

Animal models of gastric bleeding induced by dual antiplatelet therapy using aspirin and clopidogrel--prophylactic effect of antiulcer drugs.

We set up two models of gastric bleeding in rats using low-dose aspirin (ASA) and the antiplatelet drug clopidogrel, a P2Y12 receptor antagonist, and examined the effect of antiulcer drugs on gastric bleeding and ulcerogenic responses under such conditions. Under urethane anesthesia, two catheters were inserted into the rat stomach, one from the esophagus and another through the pylorus via an incision in the duodenum. In the first model, the stomach was perfused with 25 mM ASA dissolved in 50 mM HCl using an infusion pump, and gastric bleeding was measured as the hemoglobin concentration in perfusate collected every 15 min. In the second model, the stomach was perfused with ASA under stimulation of acid secretion by a continuous i.v. infusion of histamine (8 mg/kg/hr). Clopidogrel (30 mg/kg) was given p.o. 24 h before the ASA perfusion, while antiulcer drugs were given i.d. or i.v. 30 min before. Perfusion of the stomach with acidified ASA or ASA under histamine-stimulated acid secretion caused minimal bleeding in the stomach with few lesions. The ulcerogenic and bleeding responses to ASA under these conditions were markedly aggravated by pretreatment with clopidogrel, which by itself provoked neither bleeding nor damage. Antiulcer drugs, such as prostaglandin E2, irsogladine, rebamipide and teprenone, reduced the severity of gastric bleeding and damage in response to ASA plus clopidogrel in the presence of both exogenous and endogenous acid. In contrast, antisecretory drugs such as a proton pump inhibitor and histamine H2 receptor antagonists markedly suppressed the gastric bleeding and lesion responses to ASA plus clopidogrel under histamine-stimulated acid secretion, but had no effect on the responses to acidified ASA plus clopidogrel. These results suggest that clopidogrel increases gastric bleeding induced by ASA and that antiulcer drugs are useful for preventing gastric bleeding caused by the dual antiplatelet therapy.