Due to the potential for concomitant psychiatric illness and substance use disorders, understanding the potential interactions between psychotropics and drugs of abuse is important.

  • What are the potential drug-drug interactions between illicit drugs and medications?1-3
  • How does cigarette smoking (polycyclic aromatic hydrocarbons) affect medications?4-5
  • What are possible drug interactions in patients that consume alcohol?6
  • How do opioids and benzodiazepines interact? What is the clinical significance of the combination?7-9
  • How do drugs of abuse interact with anti-retroviral therapies?10
  • How do natural or synthetic cannabis interact with medications? 11-14


  1. Dean A. Illicit drugs and drug interactions. Australian Pharmacist. 2006;25(9):684-9. [Weblink]
  2. Power point presentation “Possible Drug Interactions for Students on Multiple Medications” by Sally Guthrie, Pharm.D, BCPP [Weblink]
  3. Lindsey WT, Stewart D, Childress D. Drug interactions between common illicit drugs and prescription therapies. Am J Drug Alcohol Abus. 7th ed. 2012;38(4):334-43. DOI: 10.3109/00952990.2011.643997. PubMed PMID: 22221229.
  4. Kroon LA. Drug interactions with smoking. Am J Health Syst Pharm. 2007;64(18):1917-21. DOI: 10.2146/ajhp060414. PubMed PMID: 17823102.
  5. Kohut SJ. Interactions between nicotine and drugs of abuse: a review of preclinical findings. Am J Drug Alcohol Abuse. 2017;43(2):155-170. [PubMed]
  6. Cousins G, Galvin R, Flood M, Kennedy M-C, Motterlini N, Henman MC, et al. Potential for alcohol and drug interactions in older adults: evidence from the Irish longitudinal study on ageing. Bmc Geriatr. 2014;14:57. DOI: 10.1186/1471-2318-14-57. PubMed PMID: 24766969; PubMed Central PMCID: PMC4008399.
  7. Jones JD, Mogali S, Comer SD. Polydrug abuse: a review of opioid and benzodiazepine combination use. Drug Alcohol Dependence. 2012;125(1-2):8-18. DOI: 10.1016/j.drugalcdep.2012.07.004. PubMed PMID: 22857878.
  8. McCance-Katz EF, Sullivan LE, Nallani S. Drug interactions of clinical importance among the opioids, methadone and buprenorphine, and other frequently prescribed medications: a review. Am J Addict. 2010;19(1):4-16. DOI: 10.1111/j.1521-0391.2009.00005.x. PubMed PMID: 20132117; PubMed Central PMCID: PMC3334287.
  9. U.S. Food and Drug Administration. FDA Drug Safety Communication: FDA urges caution about withholding opioid addiction medications from patients taking benzodiazepines or CNS depressants: careful medication management can reduce risks. 2017. [Weblink]
  10. Kumar S, Rao PSS, Earla R, Kumar A. Drug-drug interactions between anti-retroviral therapies and drugs of abuse in HIV systems. Expert Opin Drug Metab Toxicol. 2015;11(3):343-55. DOI: 10.1517/17425255.2015.996546. PubMed PMID: 25539046; PubMed Central PMCID: PMC4428551.
  11. Arellano AL, Papaseit E, Romaguera A, Torrens M, Farré M. Neuropsychiatric and General Interactions of Natural and Synthetic Cannabinoids with Drugs of Abuse and Medicines. CNSNDDT. 2017;16(5):554-566. DOI: 10.2174/1871527316666170413104516. PubMed PMID: 28412920.
  12. Kong TY, Kim J-H, Kim DK, Lee HS. Synthetic cannabinoids are substrates and inhibitors of multiple drug-metabolizing enzymes. Arch. Pharm. Res. 2018;41(7):691-710. DOI: 10.1007/s12272-018-1055-x. PubMed PMID: 30039377.
  13. Brown JD, Winterstein AG. Potential Adverse Drug Events and Drug-Drug Interactions with Medical and Consumer Cannabidiol (CBD) Use. J Clin Med. 2019 Jul;8(7):989. [PubMed]
  14. Qian Y, Gurley BJ, Markowitz JS. The Potential for Pharmacokinetic Interactions Between Cannabis Products and Conventional Medications. J Clin Psychopharmacol. 2019;39(5):462-471. [PubMed]
25 Years!