Pharmacokinetics of metoclopramide in patients with liver cirrhosis.

The pharmacokinetics of metoclopramide were investigated after intravenous and oral administration in eight patients with severe alcoholic cirrhosis and in eight healthy volunteers. As a consequence of a 50% lower clearance (0.16 +/- 0.07 vs 0.34 +/- 0.09 l h-1 kg-1, plasma drug concentrations and the half-life of metoclopramide were greater in patients following both routes of drug administration. Volume of distribution (3.1 +/- 0.8 vs 3.4 +/- 1.2 l kg-1) and absolute bioavailability (79 +/- 19 vs 84 +/- 15%) were similar in the two groups. The adverse effects of metoclopramide observed in patients with marked hepatic impairment are likely to result from increased accumulation of the drug as a result of impaired clearance. Consequently a reduction in dose of 50% is recommended in patients with severe liver cirrhosis.