Abstract
The administration of nifedipine by the sublingual rather than the oral route has been suggested to provide a more rapid onset of effect. We compared the safety and efficacy of s1 nifedipine to s1 nitroglycerin in patients who developed anginal chest pain during diagnostic exercise stress testing. Consecutive patients undergoing diagnostic Bruce treadmill exercise who had not had a recent myocardial infarction or undergone coronary bypass graft surgery and who were not taking nitrates, beta-blockers, digoxin, or calcium antagonists were eligible. Seventy-eight patients meeting the inclusion/exclusion criteria consented to participate. Of these 78, 13 developed chest pain necessitating exercise cessation and were randomized to either nitroglycerin or nifedipine. Nitroglycerin was initially given to seven patients and nifedipine to six patients. Complete pain relief was observed in five of seven (71 percent) nitroglycerin patients at two minutes postdose. At four minutes postdose, the remaining two nitroglycerin patients were essentially pain-free. At two minutes postdose, no patient receiving nifedipine had complete pain resolution, and only one patient (17 percent) had partial (> 50 percent) pain relief. At four minutes postdose, four of the nifedipine patients were crossed over to nitroglycerin. At two minutes after the nitroglycerin dose, all four patients had total pain relief. The remaining two nifedipine patients had partial relief and were not crossed over to nitroglycerin. Subjective side effects and changes in heart rate and blood pressure were not significantly different between nitroglycerin and nifedipine. A 10 mg dose of s1 nifedipine is not as effective as a 0.4 mg dose of s1 nitroglycerin in terminating acute exercise-induced anginal attacks within four minutes of administration, and therefore, nitroglycerin remains the drug of choice.