Nifedipine-prazosin interaction in patients with essential hypertension

In an acute, double-blind, crossover study on 12 patients with essential hypertension, the interaction between nifedipine and prazosin was investigated in the supine position. The effectiveness of the combination of the two active drugs was greater than the combination of either of the drugs plus placebo. The effect of nifedipine was not modified by prazosin pretreatment; however, the effect of prazosin was partly inhibited, i.e., delayed, by nifedipine pretreatment. Therefore, giving prazosin as a first drug and nifedipine as the second drug seems to be a better approach than the reverse.