Time-dependent variability of chloroquine secretion into human saliva

Chloroquine has been reported to be secreted into human saliva. This is a report of a study designed to underscore the importance of the finding. It involved the administration of 600 mg chloroquine per oral to seven volunteers and 150 mg by intramuscular route to six others. Blood and simultaneous saliva samples were collected and analyzed for the drug by an HPLC method. The results showed that chloroquine reaches peak concentration at the same time in both plasma and saliva after oral administration of the drug. A good correlation was obtained between the AUC values derived from saliva and plasma level data. Saliva to plasma concentration ratios obtained after administration of the drug by both routes were high (mean > 11) and exhibited a time-dependent variability. These results suggest that an active process, among other mechanisms, may be involved in the transfer of chloroquine into human saliva. Caution should be exercised in the use of saliva for therapeutic monitoring of chloroquine.