Glycopyrrolate for treatment of clozapine-induced sialorrhea in adults

PURPOSE: Four cases in which glycopyrrolate was used to treat clozapine-induced sialorrhea (CIS) are reported. SUMMARY: Glycopyrrolate is an antimuscarinic agent that can be used preoperatively to inhibit drooling and excessive secretions of the respiratory tract. The outcomes of four patients who received glycopyrrolate for the treatment of CIS are described. The Thomas-Stonell and Greenberg Drooling Severity and Frequency Scale (DSFS) was used retrospectively to rate patients' drooling. Glycopyrrolate was effective in alleviating CIS in cases 1-3. Two patients (cases 1 and 4) exhibited severe drooling, which caused their clothing, hands, and objects to consistently become wet. One patient (case 1) responded well to glycopyrrolate and was restarted on the medication when CIS returned after discontinuation of the drug. While another patient (case 3) displayed a similar response to therapy for CIS as the patient described in case 1, this patient did not experience the psychosocial complications as did the patient in case 1, possibly due to the use of glycopyrrolate as the initial treatment of choice. The patient in case 2 experienced moderate but frequent drooling. Thioridazine's high anticholinergic potential may have contributed to this patient's lower baseline DSFS score compared with the scores of the other three patients, or it could have augmented initial symptom improvement. CIS continued in the patient described in case 4 despite treatment with glycopyrrolate, with only mild improvement in the severity and frequency of drooling. CONCLUSION: Glycopyrrolate was effective in alleviating symptoms in three of four patients with CIS. In a fourth patient, the degree of improvement was unknown due to documentation discrepancies; however, mild improvement was noted initially.