Effects of neuroleptic phenothiazines on the activities of aminotransferases and gamma-glutamyltransferase in serum and liver.

Serum alanine aminotransferase, aspartate aminotransferase and gamma-glutamyltransferase activities were monitored in psychiatric patients receiving normal doses of phenothiazine neuroleptics over a 30-day period. The first two enzymes showed slight initial increases and a subsequent return to normal, while the third showed a slight increase. In rats, dosage levels exceeding those used in human therapy produced much larger increases in the catalytic concentrations of all three enzymes in serum (1.4, 0.7 and 0.5 above the control value, respectively), and somewhat smaller increases in the liver homogenates of these animals.