Psychopharmacology
March 7, 2022
Aryan Sarparast, Kelan Thomas, Benjamin Malcolm et al.
85 citations
As MDMA and psilocybin progress through FDA drug development, this systematic review compiles existing research on psychiatric drug-drug interactions with these substances. It identifies which medications may alter the effects or safety of MDMA- and psilocybin-assisted therapy, providing a resource for clinicians and researchers. The review suggests that certain psychiatric drugs, such as SSRIs and other serotonergic agents, can diminish or alter the subjective and physiological responses to MDMA and psilocybin, while others may increase risks. The authors indicate that careful medication management is necessary during psychedelic-assisted therapy to optimize outcomes and minimize adverse events.
Journal of Psychoactive Drugs
May 8, 2017
Kelan Thomas, Benjamin Malcolm, Dan Lastra
77 citations
A review of seven clinical trials found that psilocybin-assisted therapy reduced symptoms of anxiety, depression, and substance use, with large effect sizes for improved depression and anxiety. Reductions in alcohol or tobacco use and increased abstinence rates in addiction were less clear due to open-label designs without statistical analysis. The therapy appears promising, but more robust trials are needed for FDA approval.
Scientific Reports
March 16, 2021
Isaac Cohen, Tigran Makunts, Ruben Abagyan et al.
30 citations
Using FDA drug safety surveillance data, nearly one thousand reports of MDMA use were analyzed to evaluate risks of death when MDMA is taken alone or with other medications. Several drug classes—including MDMA metabolites or analogs, anesthetics, muscle relaxants, amphetamines and stimulants, benzodiazepines, ethanol, and opioids—along with the antidepressants bupropion, sertraline, venlafaxine, and citalopram, and the antipsychotic olanzapine, showed increased odds ratios for reported risk of death. The authors call for future clinical trials to assess whether these drug–drug interactions pose actual harm in controlled medical settings.
Journal of Psychopharmacology
September 12, 2025
Stephan Tap, Kelan Thomas, Tomáš Páleníček et al.
5 citations
Classic psychedelics like psilocybin are being studied for psychiatric disorders. Current protocols typically require patients to stop antidepressants (ADs) for at least two weeks before psychedelic use to avoid serotonin syndrome and preserve efficacy, but discontinuation can worsen depression and increase suicidal ideation. This scoping review of 18 studies found that using ADs alongside classic psychedelics is generally safe and tolerable, with no increased risk of serotonin syndrome, especially with psilocybin. Some studies showed significant improvements in depression and other symptoms. Although some evidence suggests a potential reduction in acute subjective psychedelic effects, this was not consistent. The authors conclude that maintaining ADs may improve patient access and avoid discontinuation risks.
Current topics in behavioral neurosciences
July 24, 2024
Kelan Thomas
3 citations
As psychedelics are studied for more medical uses, understanding their adverse effects and interactions with other drugs is increasingly important. This chapter reviews the known toxicology and drug-drug interactions of classic psychedelics, including LSD, psilocybin, DMT, 5-MeO-DMT, mescaline, 2C-B, Bromo-DragonFLY, and 25X-NBOMe.
Journal of the American College of Clinical Pharmacy
October 1, 2023
Kelan Thomas
Pharmacists will increasingly field questions about psychedelic medicines as FDA approval of MDMA for PTSD and psilocybin for major depressive disorder is expected in 2024 and 2025, respectively. Psychedelics differ from other mental health treatments by requiring only a few doses with psychological support, spaced months apart, which may yield enduring symptom improvements. Policymakers have proposed various regulatory frameworks for public access beyond FDA approval, including religious use protected by the Religious Freedom Restoration Act and state-level systems in Oregon and Colorado. Pharmacists must educate themselves on pharmacological mechanisms, adverse effects (e.g., transient anxiety, elevated heart rate, rare serotonin toxicity, valvular heart disease risk with microdosing), and drug–drug interactions. Professional guidelines and a dramatic increase in psychedelic research publications support this emerging field.
Journal of forensic sciences
September 1, 2015
Paul J Perry, Kristian Fredriksen, Stephanie Chew et al.
A single 120 mg dose of dextromethorphan, the maximum recommended daily dose, does not impair driving performance or increase failures on a standardized field sobriety test compared to a 400 mg dose of guaifenesin. Forty healthy adults completed a crossover trial using a driving simulator and field sobriety tests one hour after taking the drug. Doses higher than 120 mg are needed to affect driving behavior. Dextromethorphan is commonly abused by adolescents for its dissociative effects, but at the maximum therapeutic dose it does not appear to compromise driving ability.