A Safety Signal of Somnambulism with the Use of Antipsychotics and Lithium: A Pharmacovigilance Disproportionality Analysis

Abstract

Background: Antipsychotics and lithium are widely used in psychiatry, particularly in schizophrenia and bipolar disorders. Recently, some cases of somnambulism or sleep-related eating disorder (SRED) have been reported in patients treated with these drugs. This study investigates the risk of reporting of somnambulism or SRED associated to the use of antipsychotics and lithium. Methods: The World Health Organization pharmacovigilance database (VigiBase), comprising more than 18 million adverse events, was queried. All somnambulism or SRED reports related to antipsychotics or lithium were identified. The association between antipsychotics or lithium and somnambulism or SRED was computed using proportional reporting ratio (PRR) and information component (IC). Outcomes Among the 5,784 cases reporting a somnambulism or SRED, 508 suspected at least one antipsychotic or lithium. Most of patients were aged 18-64 years (62·0%), and 37·0% were men. In most of cases (77·6%), antipsychotic or lithium were the only drug class involved, and 53·3% of cases suspected the quetiapine. Somnambulism was reported in 88·6% of ICSRs, and SRED in 18·1%. A significant association were found for second-generation antipsychotic (PRR 3·44, 95% CI 3·13) and lithium (PRR 2·03, [1·22; 3·37]), yet not for first-generation antipsychotics (PRR 0·99, [0·68; 1·44]). Interpretation: The present study found a significant signal of somnambulism or SRED related to second-generation antipsychotics and lithium. If case reports mentioned mostly quetiapine and olanzapine, almost all second-generation antipsychotics were associated with somnambulism or SRED. Funding Statement: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Declaration of Interests: Dr A. Gouverneur, Dr A. Ferreira, Dr C. Morival, Dr C. Pageot, and Pr M. Tournier have no conflict of interest to disclose. Pr. A. Pariente reports and acting as an independant expert towards the French Medicines Agency (Agence Nationale de Securite du Medicament et des Produits de Sante, ANSM) and the European Medicines Agency (EMA). AP coordinates the DRUGS Systematised Assessment in real-liFe EnviRonment (DRUGS-SAFER ) programme funded by the Agence Nationale de Securite du Medicament et des Produits de Sante (ANSM). This program aims at providing an integrated system allowing the concomitant monitoring of drug use and safety in France. The present study was not included in the DRUGS-SAFER programme. Ethics Approval Statement: Not required.