Parasomnias and sleep-related movement disorders induced by drugs in the adult population: a review about iatrogenic medication effects.

Parasomnias and sleep-related movement disorders (SRMD) are major causes of sleep disorders and may be drug induced. The objective of this study was to conduct a systematic review of the literature to examine the association between drug use and the occurrence of parasomnias and SRMD. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for reporting systematic reviews, we searched PubMed databases between January 2020 and June 2023. The searches retrieved 937 records, of which 174 publications were selected for full-text screening and 73 drugs were identified. The most common drug-induced parasomnias were nightmares and rapid eye movement (REM) sleep behaviour disorders and sleepwalking. In terms of drug-induced SRMD, restless legs syndrome, periodic limb movement disorders (PLMD), and sleep-related bruxism were most frequent. Medications that inhibit noradrenergic, serotonergic, or orexin transmission could induce REM sleep (e.g., nightmares). Regarding sleepwalking, dysregulation of serotoninergic neurone activity is implicated. Antipsychotics are mentioned, as well as medications involved in the gamma-aminobutyric acid (GABA) pathway. A mechanism of desensitisation-autoregulation of GABA receptors on serotoninergic neurones is a hypothesis. SRMD and PLMD could involve medications disrupting the dopamine pathway (e.g., antipsychotics or opioids). Opioids would act on mu receptors and increase dopamine release. The role of adenosine and iron is also hypothesised. Regarding bruxism, the hypotheses raised involve dysregulation of mesocortical pathway or a downregulation of nigrostriatal pathway, related to medications involving dopamine or serotonin. Parasomnias are rarely identified in drug product labels, likely due to the recent classification of their diagnoses. An analysis of pharmacovigilance data could be valuable to supplement existing literature data.