Opioid toxicity due to CNS depressant polypharmacy: A case report

• Main Authors: Christine Lee (Author), Annabelle Wanson, MD, FRCPC (Author), Sarah Frangou, BSc, MD (Author), David Chong, BSc, MSc, BMBS (Author), Katelyn Halpape, BSP, ACPR, PharmD, BCPP (Author)
• Format: Book
• Published: American Association of Psychiatric Pharmacists, 2021-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 2168-9709; 10.9740/mhc.2021.03.070
• Keywords: central nervous system depression; cns; methadone; drug interactions; opioid use disorder; concurrent disorder; Neurosciences. Biological psychiatry. Neuropsychiatry; RC321-571; Pharmacy and materia medica; RS1-441
• Source: Mental Health Clinician, Vol 11, Iss 2, Pp 70-74 (2021)

The interaction between methadone and central nervous system depressants can cause serious adverse effects, including profound sedation, respiratory depression, coma, and death. This poses a challenge in the treatment of patients with concurrent psychiatric and substance use disorders as the combined use is often unavoidable. We report a case of a patient with opioid use disorder, mood disorder unspecified, chronic pain, and chronic obstructive pulmonary disease who experienced 2 serious episodes of CNS and respiratory depression due to polypharmacy-induced opioid toxicity. Careful consideration of pharmacokinetics, pharmacodynamics, and patient-specific factors was imperative to identify the suspected contributing medications: methadone, lorazepam, divalproex, gabapentin, and cyclobenzaprine. Cognitive and system factors that contributed to these adverse events and strategies to mitigate risk of recurrence were also identified.