3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy: what the pharmacist needs to know

Purpose of Review: On 1 July 2023, the Therapeutic Goods Administration approved 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for the treatment of post-traumatic stress disorder (PTSD). Accordingly, the purpose of this review is to provide an overview of MDMA and what pharmacists should know as this treatment emerges. Sources of Information: EMBASE, MEDLINE, and CINAHL databases were searched to provide an overview narrative synthesis of the literature on MDMA, relevant to pharmacists. Key Findings: Cytochrome P450 2D6 is involved in the metabolic pathway of MDMA, an enzyme inhibited by a number of drugs used in the pharmacological management of PTSD (e.g. selective serotonin reuptake inhibitors). Co-administration of these drugs with MDMA can lead to increases in plasma MDMA concentrations. Additionally, inhibition of the serotonin transporter can inhibit the uptake of MDMA into the presynaptic terminal, dampening the effects of MDMA and potentially, limiting the effectiveness of MDMA-assisted psychotherapy. Accordingly, these drugs are typically withdrawn prior to treatment with MDMA. While selective serotonin reuptake inhibitor/serotonin noradrenaline reuptake inhibitor drugs with MDMA are unlikely to cause serotonin toxicity, monoamine oxidase inhibitors can. Other drugs, such as caffeine, alcohol, over-the-counter medicines, and complimentary/alternative medicines, can also interact with MDMA. Conclusion: With a detailed knowledge of the pharmacology of MDMA, pharmacists may play a role in MDMA-assisted psychotherapy by collecting a detailed medication history and assisting clinicians in the withdrawal of interacting medicines.