Salivary flow-rate and composition in schizophrenic patients on clozapine: subjective reports and laboratory data.

The extent of hypersalivation was evaluated in a group of 25 schizophrenic patients on clozapine. A high prevalence of the complaint was detected by a questionnaire; up to 80% of the patients complained of hypersalivation at night. Salivary flow-rate and composition was examined in 17 patients who agreed to participate and in a matched group of healthy controls. No significant differences were detected in composition or flow-rates of resting and stimulated saliva. The salivary flow-rates in the schizophrenic patients on clozapine did not correlate with the subjective complaint of hypersalivation. Because the severity and prevalence of the complaint was higher at night, a possibility of an altered circadian rhythm of salivation might be suggested in these patients.