Paracetamol and conventional antimalarial drugs induced hepatotoxicity and its protection by methionine in rats.

Hepatotoxicity, induced in rats, by treatment with high doses of paracetamol and chloroquine was confirmed by estimating blood transaminase levels. Hepatoprotective effect was determined by administering combination of methionine (10% of paracetamol/chloroquine, p.o.) and hepatotoxic drugs quinine. The results were confirmed by histopathological examination of liver. Paracetamol (7 g/kg) and chloroquine (970 mg/kg) administration increased significantly the transaminase levels. Methionine alone did not produced any change. Hepatonecrosis induced by paracetamol, chloroquine alone and their combinations and its protection with methionine was revealed by histopathological study whereas the combination of paracetamol and methionine showed no significant histopathological difference when compared to the normal liver section. The results reveal that, methionine significantly prevented the rise in transaminases levels produced by hepatotoxic doses of paracetamol and chloroquine. But, to prevent occasional cases of paracetamol overdosage, it is not advisable to give methionine concurrently with paracetamol to patients who are taking paracetamol therapeutically.