Use of Prescribed Psychotropic Medications in an Opioid Substitution Therapy Cohort.

Objective: Comorbid mental illness is extremely common in individuals receiving opioid substitution therapy. The use of common psychiatric medications is complex in this cohort with increased risks of drug–drug interaction, overdose, and diversion or abuse of prescribed medication. We have therefore investigated rates of co-prescribing and psychiatric comorbidity in a cohort of individuals receiving therapeutic methadone or buprenorphine. Methods: Comprehensive electronic medical records were accessed for a cohort of individuals (n = 698) receiving opioid substitution therapy at a single center in London, United Kingdom. The following was collected for each individual: demographic data, current prescribed medications (including opioid substitution therapy agents), duration of prescription, indication for each prescription, and psychiatric diagnoses. Results: A total of 610 individuals were included in the final analysis. High rates of psychotropic co-prescribing were observed, with 36.7% of individuals receiving a psychotropic medication in addition to their opioid substitution drug, including 35.4% receiving an antidepressant, 9.2% an antipsychotic, 8.6% a benzodiazepine, and 4.5% a gabapentinoid, rates that are far in excess of the local population prescription frequency; 75.5% of antipsychotic prescriptions and 47.7% of benzodiazepine prescriptions were for an unlicensed indication. Conclusions: This highlights the need for evidence-based treatment of comorbid mental illness for individuals receiving opioid substitution therapy. [ABSTRACT FROM AUTHOR]