Factors that affect the induction of gamma glutamyltransferase in epileptic patients receiving anti-convulsant drugs.

Serum samples from 335 epileptic patients receiving one or more anticonvulsant drugs, phenobarbitone, primidone and phenytoin, have been analysed for biochemical liver profile (BLP) and serum drug concentration. The results show that the induction of serum gamma glutamyltransferase (GGT) is affected by the sex and age of the patient, type of anti-convulsant drug prescribed and duration of treatment. It is less affected by serum drug concentration. It is suggested that these factors must be considered when interpreting results involving serum GGT activity as the index of microsomal enzyme induction.