Calcium antagonist treatment and cardiovascular responses to a cold pressor test at high altitude

Objective: We assessed the effects of the calcium antagonist felodipine on blood pressure, heart rate, oxygen saturation and cardiovascular responses to a cold presser test at an altitude of 5200 m. Sixteen healthy climbers participated. A double-blind, placebo-controlled, randomized, crossover design was used. Placebo or felodipine were taken for 2 days and the treatment was changed after 3 days washout. Results. During felodipine treatment there were no significant changes in blood pressure (125/89 vs 127/86 mmHg), heart rate (82 vs 81 beats . min(-1)) or oxygen saturation (86% vs 86%). Moreover, there were no changes in the cardiovascular responses to the cold presser test. Conclusion: Felodipine is well tolerated at high altitude. It does not induce hypotension in normotensive men and does not affect cardiovascular reactivity to cold stress.