Effects of nifedipine on the venodilatory response to nitroglycerin

The venodilatory effect of nifedipine 10 mg orally and the venodilatory effect of nitroglycerin 0.8 mg spray after pretreatment with nifedipine were assessed in 15 healthy men aged 22 to 41 years. Compared to placebo, nifedipine caused arteriolar dilation but did not venodilate (control VV[30] 3.67 +/- 0.24 [mean +/- standard error of the mean], after nifedipine VV[30] 3.41 +/- 0.22 cc/100 cc arm). The venodilatory effect of nitroglycerin was not altered by pretreatment with nifedipine. VV[30] increased by 0.72 +/- 0.14 cc/100 cc arm after nitroglycerin in subjects pretreated with placebo compared to 0.70 +/- 0.09 cc/100 cc arm in subjects pretreated with nifedipine. These results suggest that, at a dose of 10 mg, nifedipine does not venodilate and the venodilatory effect of nitroglycerin is not altered by pretreatment with nifedipine.