Pharmacokinetic and pharmacodynamic parameters in patients treated with nitrendipine.

Nitrendipine (BAY e 5009) is a new calcium channel blocker with a marked effect on excitation-contraction coupling in different types of muscle cells. It has many similarities to the established agent, nifedipine. In the present study, nitrendipine was evaluated in a double-blind within-patient comparison. Twelve patients with essential hypertension were given nitrendipine 20 mg or 40 mg orally for three weeks following a 1-week placebo period. After a second 1-week placebo period, there was a crossover to the alternative dosage (20 or 40 mg respectively), and active therapy was again given for 3 weeks. Both doses of nitrendipine caused a significant and equal reduction of arterial pressure, which persisted for at least 24 hours. Only the highest dose caused an increase in heart rate. There were a few reports of headaches, flushing, and palpitation, particularly after the 40 mg dose. There was a significant correlation between the reduction of mean arterial pressure and the log plasma concentration (20 mg: r = -0.88, p less than 0.01; 40 mg: r = -0.94, p less than 0.001). There was a linear relationship between the area under the curve and the oral dose, indicating that liver enzyme saturation had not occurred. There was no accumulation of nitrendipine in plasma during 3 weeks of treatment.