Clinical pharmacology of lacidipine

The safety and tolerability of lacidipine was assessed in a volunteer population, and its pharmacodynamic and pharmacokinetic profiles evaluated. In normotensive subjects, single oral doses of 3-5 mg of lacidipine produced a dose-related fall in peripheral vascular resistance. This was accompanied by reflex-mediated increases in heart rate and cardiac output to maintain blood pressure. Adverse events were those typically related to the vasodilatory action of lacidipine, such as flushing and headache. A 4-mg dose of lacidipine elicited a cardiovascular response equivalent to that with 10 mg of nifedipine, given as a single oral dose. Lacidipine did not affect sinoatrial or atrioventricular conduction in the healthy subjects studied. Two specialized electrophysiologic studies in patients confirmed that lacidipine does not affect pacemaker tissue and that it exhibits relative selectivity for the vascular smooth muscle. Lacidipine is eliminated primarily by hepatic metabolism, and extensive first-pass loss occurs after oral dosing. Absolute bioavailability is less than 10%. The systemic availability of lacidipine was increased in healthy elderly subjects and in patients with impaired hepatic function, but not in patients with impaired renal function.