Plasma gamma-glutamyl transpeptidase in heroin addicts

Plasma gamma-glutamyl transpeptidase was measured in 25 heroin addicts. The purpose was to find out if the long term administration of heroin would lead to a stimulation of GGTP due to the detoxication of this drug in the endoplasmatic reticulum of the liver. In 10 patients the elevation of GGTP could be attributed to liver damage, since other liver enzymes were also increased. 15 patients had normal GGTP activities, in 4 of them accompanied by minor elevations of single other hepatic enzymes. In 11 patients the GGTP activity as weel as that of the other enzymes was normal despite heavy chronic herioin abuse. It is therefore improbable that GGTP can be used to diagnose abuse of this drug and to evaluate the progress of drug detoxication treatments and drug abstention as has been proposed in chronic alcoholism.