Clonidine Improves Exercise Tolerance in Angina Pectoris And the effects are sustained with chronic administration

In a randomised double-blind crossover study, 12 patients with chronic effort angina of ~ 6 months' duration who had ~ 5 anginal episodes/week received, after a 2-week placebo washout period, clonidine 200~g bid for 3 weeks followed by 400~g bid for the next 3 weeks (n = 5) or matching placebo for 6 weeks. During the next week patients were tapered off medication and after a 2-week placebo washout period, were crossed over to alternate treatment.

One and 2 hours after clonidine 200~g. resting and exercise rate-pressure product decreased significantly (p < 0.05). One hour after clonidine administration, exercise duration increased from 345 to 403 seconds and decreased to 392 seconds after 2 hours. After 3 and 6 weeks of clonidine treatment rate-pressure product at rest and during exercise decreased significantly. Exercise duration increased after 3 weeks of both clonidine and placebo treatment. After 6 weeks, exercise duration decreased with placebo while the increase persisted with clonidine. In those patients receiving clonidine during the first phase of the trial, exercise duration remained elevated during the 3-week crossover period. Thus, the acute effects of clonidine in patients with angina pectoris are sustained with chronic administration.

Thomas MG, Quiroz AC, Rice JC, Sander GE, Giles TO. Journal of Cardiovascular Pharmacology 8 (Suppl. 3): S69·S75, 1986

16 INPHARMA® 7 Feb 1987 0156-2703/87/0207-0016/0$01.00/0 © ADIS Press