The contributions of various chloroquine salts to the biliary and urinary execretion of hepatic paracetamol conjugation metabolites in the rat.

As an approach to explain the possible in vivo interaction of paracetamol (acetaminophen) with various chloroquine salts that are often administered during malaria tropica, the effects of these salts (chloroquine sulphate, chloroquine phosphate, chloroquine hydrochloride and ferrous sulphate) were examined in male rats. The coadministration of chloroquine salts with paracetamol for 7 days showed varied effects on urinary and biliary excretion of paracetamol sulphate and paracetamol glucuronide conjugates--the major metabolites of paracetamol metabolism. These findings suggest that chloroquine sulphate and ferrous sulphate may enhance the sulphation pathway in paracetamol metabolism and influence detoxification of paracetamol in the liver and thus protect the liver. Chloroquine sulphate is therefore a better choice compared to other chloroquine salts in the treatment of malaria with paracetamol as an antipyretic and analgesic.