[Increase in liver circulation with nifedipine].

The hepatic hemodynamic effect of 20 mg sublingual nifedipine was evaluated in 15 patients (13 men, 2 women) during heart catheterization. The liver blood flow was measured 10 min after administration of nifedipine by continuous thermodilution (Baim coronary sinus flow analyzer). Nifedipine was associated with a decrease in systolic blood pressure (from 156 +/- 14 to 138 +/-13 mmHg), an increase in heart rate (from 73 +/- 13 to 81 +/- 8.6 beats/min), and increase in cardiac output (from 6.0 +/- 1.6 to 6.5 +/- 1.3 l/min). In 2/15 patients no significant change was derived. The liver blood flow increased in 13/15 patients from 218 +/- 171.7 to 336.7 +/- 247.7 ml/min (22%-194%, P less than 0.01). The study demonstrates that the vasodilation of nifedipine involves the hepatic circulation. If the hepatic clearance of drugs is high and flow dependent, nifedipine-induced increase of hepatic blood flow may impair drug clearance.