Effect of some non-steroidal anti-inflammatory drugs on ouabain-induced arrhythmias in guinea-pigs.

1. Effects of some non-steroidal anti-inflammatory drugs on ouabain-induced arrhythmias in guinea-pigs were studied. 2. Ventricular premature beats, ventricular fibrillation and cardiac arrest were induced in pentobarbitone-anaesthetized guinea-pigs by a slow intravenous infusion of ouabain. 3. Aspirin and indomethacin were found to accord a significant protection to the guinea-pigs against arrhythmias whereas ketoprofen was found to be ineffective. 4. It is concluded that the protective effect of aspirin and indomethacin may be due to inhibition of synthesis and release of thromboxane A2 from the myocardium.