THE INFLUENCE OF NIMODIPINE ON HEMODYNAMIC PARAMETERS AND PEAK AND TROUGH PLASMA-CONCENTRATIONS OF NIFEDIPINE CHRONICALLY ADMINISTERED TO ELDERLY HYPERTENSIVE PATIENTS

Possible drug interactions between the two calcium channel blockers ni modipine and nifedipine were investigated in 12 elderly patients with stable mild to moderate hypertension. Their individually adjusted nife dipine treatment had been unchanged for at least 5 weeks. There was no evidence of significant changes in nifedipine efficacy as seen from b lood pressure and heart rate after a 7-day comedication of 30 mg nimod ipine t.i.d. as compared with the findings after combined administrati on of nifedipine and placebo. Nifedipine steady-state trough and peak concentrations were not significantly altered by concomitant nimodipin e administration. On the other hand, nifedipine did not affect nimodip ine trough and peak concentrations when compared with published data. Differences in clinical chemistry or tolerance between both treatment regimens did not occur or were marginal, respectively. In conclusion, a clinically relevant drug interaction between nifedipine and nimodipi ne which might be potentially harmful for patients with hypertension w as not observed in this study.