CHLORPROMAZINE TO TREAT ADULT SOMATIC COUGH SYNDROME

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Chlorpromazine is a centrally acting dopamine antagonist used for psychogenic singultus. Somatic cough syndrome is associated with an underlying psychiatric disorder and improves with behavioral or pharmacologic therapy. Diagnostic criteria include cough for >6 months with disruption of daily life and associated anxiety. CASE PRESENTATION: A 46 year old female presented with worsening dyspnea secondary to heavy coughing spells. Chest radiograph was unremarkable. CT angiogram showed atelectasis and possible pneumonia. She was treated with ceftriaxone and azithromycin for CAP, however cough did not improve. The patient developed stridor and hypoxic and hypercarbic respiratory failure requiring endotracheal intubation. Laryngoscopy did not demonstrate inflammation or edema. She remained intubated and sedated for two days. After extubation, the cough returned. Physical examination was benign. The patient’s breathing was unlabored and she was able to speak in full sentences. No cough was present while asleep. Repeat imaging was unremarkable. She received ipratropium-albuterol nebs every 6 hours and albuterol PRN. Benzonatate, guaifenesin, codeine, and nebulized lidocaine were tried, but the cough persisted. The decision was made to use chlorpromazine 25 mg PO every 8 hours. Patient’s cough resolved completely after the second dose. Psychiatry consultation attributed the patient’s cough to generalized anxiety disorder. She was started on duloxetine 60 mg daily with recommendation to titrate off the chlorpromazine with improvement of cough. Six months later, our patient re-presented similarly – intractable cough with respiratory failure requiring endotracheal intubation. Given our previous evidence of the efficacy of chlorpromazine in resolution of her cough, patient was extubated on day 2 with initiation of 25 mg chlorpromazine q8h. Once again, her cough resolved after the second dose. DISCUSSION: Singultus and cough have similar mechanisms. They activate neural reflex arcs including the vagus and phrenic nerves leading to spasmodic contraction of the diaphragm. This action is mediated in part by dopaminergic activity. Multiple neuromodulatory agents have been studied, with improvement of refractory singultus. Pregabalin with speech therapy has been evaluated in an RCT for refractory cough with better outcomes over therapy alone. Also, a case study demonstrated resolution of refractory cough with risperidone plus therapy. This suggests that decreased neurotransmitter activity is beneficial in treatment of refractory cough. Chlorpromazine’s dopamine antagonism results in decreased reflex activation, likely leading to improvement of singultus and cough. CONCLUSIONS: Neuromodulation should be further studied for treatment of somatic cough syndrome. Reference #1: Irwin RS et al. Habit Cough, Tic Cough, and Psychogenic Cough in Adult and Pediatric Populations. CHEST. 2006; 129(1):174-179. doi.org/10.1378/chest.129.1_suppl.174S Reference #2: Steger M et al. Systemic review: the pathogenesis and pharmacological treatment of hiccups. Aliment Pharmacol Ther. 2015; 42(9):1037-1050. doi:10.1111/apt.13374 Reference #3: Vertigan AE et al. Pregabalin and Speech Pathology Combination Therapy for Refractory Chronic Cough. CHEST. 2016; 149(3):639-648. doi.org/10.1378/chest.15-1271 DISCLOSURES: No relevant relationships by Michael Bonk, source=Web Response No relevant relationships by Firth Bowden, source=Web Response No relevant relationships by Kia Ghiassi, source=Web Response No relevant relationships by Ananya Nanduri, source=Web Response