ABSTRACT
OBJECTIVE: To describe a case of clozapine-induced sialorrhea alleviated by immediate-release oxybutynin. CASE SUMMARY: A 53-year-old female with schizoaffective disorder-bipolar type was admitted to a psychiatric unit and initiated on clozapine. During titration to a dose of 300 mg daily and despite taking concomitant oral benztropine 1 mg twice daily, the patient began to experience mild sialorrhea. The sialorrhea became profuse when the clozapine dose reached 400 mg daily, and the patient was routinely seen with a saliva-soaked shirt. Additionally, she had become self-conscious and wanted to stop clozapine therapy. Immediate-release oxybutynin 5 mg daily was started, resulting in significant reduction of the sialorrhea within 24 hours. The patient was discharged on clozapine 300 mg daily, risperidone 6 mg at bedtime, immediate-release oxybutynin 5 mg twice daily, and oral benztropine 1.5 mg daily, with only mild sialorrhea. DISCUSSION: It is unknown why clozapine induces sialorrhea. One speculation is that clozapine interrupts muscarinic receptor homeostasis. Immediate-release oxybutynin is an anticholinergic agent with high affinity for salivary gland M3 receptors that may have restored muscarinic receptor imbalance in our patient. N-Desethyl-oxybutynin, an active metabolite of oxybutynin, is largely responsible for oxybutynin's anticholinergic activity. The activity of oxybutynin and its metabolite may result in dry mouth in over 80% of patients taking the immediate-release formulation, while producing dry mouth in only 40% and 7.5% of patients taking the extended-release and topical formulations, respectively. CONCLUSIONS: To our knowledge, this is the first report of immediate-release oxybutynin successfully reducing clozapine-induced sialorrhea. If oxybutynin is considered for this indication, use of the immediate-release formulation seems prudent. Additional data, including randomized controlled trials, are needed to confirm whether immediate-release oxybutynin has a significant role in the management of this stigmatizing adverse effect.
Subject(s)
Clozapine/adverse effects , Mandelic Acids/therapeutic use , Sialorrhea/drug therapy , Antipsychotic Agents/adverse effects , Antipsychotic Agents/therapeutic use , Bipolar Disorder/drug therapy , Clozapine/therapeutic use , Female , Humans , Mandelic Acids/administration & dosage , Middle Aged , Muscarinic Antagonists/administration & dosage , Muscarinic Antagonists/therapeutic use , Psychotic Disorders/drug therapy , Sialorrhea/chemically inducedABSTRACT
We conducted a retrospective study of 13 patients with parathyroid carcinoma to assess their clinical characteristics and surgical outcomes. Study parameters included patient demographics, survival, treatment response, and recurrence. We found that all patients who had undergone local tumor excision developed a recurrence, compared with only 33% of those available for follow-up after en bloc tumor resection. Based on these findings, we recommend en bloc tumor resection as the initial treatment of choice for patients diagnosed with parathyroid carcinoma.
