Liver size and indices of drug metabolism in epileptics.

1 The relationship between liver size and in vivo (antipyrine kinetics) and in vitro (cytochrome P-450) drug metabolism was investigated in twenty-one epileptics on long-term anticonvulsant therapy and in controls. 2 The epileptics exhibited significant enlargement of the liver and enhancement of drug metabolism compared to the controls. 3 Liver size correlated to antipyrine kinetics only in controls. Concentration of cytochrome P-450 in liver biopsy specimens correlated with liver size neither in controls nor in epileptics. 4 The total hepatic cytochrome P-450, estimated on the basis of liver weight and cytochrome P-450 concentration of biopsy samples, correlated linearly with antipyrine kinetics, except in patients with the most severely disturbed liver architecture. 5 Measurement of liver size is essential when comparing in vivo and in vitro drug metabolism, but the changes in liver histology are also of great importance.