The antihypertensive effect of beta-blockers may be augmented by nifedipine's reduction of peripheral vascular resistance. The concomitant administration of nifedipine with beta-adrenergic blocking drugs warrants caution and careful monitoring of the blood pressure and pulmonary signs and symptoms of congestive failure. (See Warnings.)
Long acting nitrates: Nifedipine may be safely co-administered with nitrates, but there have been no controlled studies to evaluate the antianginal effectiveness of this combination.
Antihypertensives: Nifedipine may potentiate the effects of hypotensive agents.
Concomitant use of nifedipine together with short acting nitrates, digitalis glycosides, furosemide and anticoagulants has shown no interaction or unusual toxic effects.
It has been reported that concurrent administration of cimetidine and nifedipine results in an almost doubling of peak nifedipine plasma, level. Patients receiving the two drugs concomitantly should be watched carefully for the possible exacerbation of effects of nifedipine, e.g. hypotension. Adjustment of the nifedipine may be necessary.