Haemodynamic effects of combined oral nifedipine and sublingual nitroglycerin in patients with chronic stable angina.

We examined the pharmacokinetics of nifedipine after acute and sustained oral therapy and the potential haemodynamic interaction between nifedipine and sublingual nitroglycerin in nine patients with chronic stable angina. Nifedipine pharmacokinetics after a single oral dose and sustained dosing (three times daily for five days) were not significantly different. Single dose nifedipine produced a statistically significant decrease in standing and supine systolic and diastolic blood pressures when compared to placebo. A significant decrease in the supine systolic pressure was observed after sustained nifedipine therapy. Except for this change, other hypotensive effects of nifedipine after sustained therapy were not different to those of placebo, in spite of persistent plasma nifedipine concentrations after repeated dosing. There were no observable correlations between nifedipine haemodynamics and pharmacokinetics in these patients, nor were there any significant haemodynamic interactions between sublingual nitroglycerin with either acute or sustained nifedipine treatment. The transient haemodynamic effects of sublingual nitroglycerin were not potentiated by either acute or sustained nifedipine therapy.