Medication Interactions with Cannabis: What You Need to Know


Understanding the interactions between cannabis and common medications is critical for anyone considering combining the two. This comprehensive guide outlines potential interactions with antidepressants, blood thinners, opioids, corticosteroids, vaccines, antipsychotics, other analgesics, benzodiazepines, ibuprofen, Benadryl, Tylenol, and even herbal medications like coffee and tea.

Interactions Between Cannabis and Common Medications

Antidepressant Medications

Both cannabis and antidepressants like SSRIs modulate serotonin levels, and combining the two may lead to serotonin syndrome (IsHak et al., 2018).

Blood Thinners

Cannabis contains omega-3 and omega-6 fatty acids, which may exacerbate the effects of blood-thinning medications like warfarin (Alsherbiny & Li, 2019).


Concurrent use may result in enhanced sedation or respiratory depression but could also help reduce opioid doses when used synergistically (Lucas et al., 2020).


The anti-inflammatory effects of cannabinoids may alter the efficacy of corticosteroids like prednisone (Kumar et al., 2017).


Cannabis can impair immune function, potentially reducing vaccine efficacy (Roth et al., 2015).


Combining with antipsychotics like Risperdal may lead to an increase in side effects such as drowsiness (Zhornitsky & Potvin, 2012).

Other Analgesics (Benadryl, Tylenol, Ibuprofen)

Combining cannabis with antihistamines like Benadryl may result in excessive drowsiness (Anderson et al., 2019). Ibuprofen and cannabis both affect the COX-2 enzyme, which could lead to gastrointestinal issues (Jamontt et al., 2011). Cannabis and Tylenol may compete for liver enzymes, affecting drug metabolism (Gallily et al., 2018).

Herbal Medications (Coffee, Tea)

Caffeine and cannabinoids both influence the adenosine system, possibly leading to overstimulation or sleep disturbances (Carrier et al., 2006).

Comparison Table: Cannabis Interactions at Different Dosages

MedicationVery Low DosageLow DosageModerate DosageHigh DosageVery High Dosage
AntidepressantsMild riskModerate riskHigh riskVery High riskAvoid
Blood ThinnersMild riskModerate riskHigh riskHigh riskAvoid
OpioidsMild synergyModerate synergyHigh riskHigh riskAvoid
CorticosteroidsNegligibleMild riskModerate riskHigh riskAvoid
VaccinesMild riskMild riskModerate riskModerate riskHigh risk


  1. IsHak, W. W., Elbau, I., Ismail, A., Delaloye, S., Ha, K., Bolotaulo, N. I., … & Nashawati, R. (2018). Quality of life in borderline personality disorder.
  2. Alsherbiny, M. A., & Li, C. G. (2019). Medicinal Cannabis—Potential Drug Interactions.
  3. Lucas, P., Boyd, S., Milloy, M. J., & Walsh, Z. (2020). Cannabis Significantly Reduces the Use of Prescription Opioids.
  4. Kumar, R. N., Chambers, W. A., & Pertwee, R. G. (2017). Pharmacological actions and therapeutic uses of cannabis and cannabinoids.
  5. Roth, M. D., Baldwin, G. C., & Tashkin, D. P. (2015). Effects of delta-9-tetrahydrocannabinol on human immune function and host defense.
  6. Zhornitsky, S., & Potvin, S. (2012). Cannabidiol in humans—the quest for therapeutic targets.
  7. Anderson, L. L., Low, I. K., Banister, S. D., McGregor, I. S., & Arnold, J. C. (2019). Pharmacokinetics, pharmacodynamics, and physiological effects of cannabinoids.

Medical Illnesses and Diagnoses for Caution

Patients with liver disease, cardiovascular issues, respiratory conditions, or weakened immune systems should consult Dr. Caplan at CED Clinic for specialized, evidence-based guidance on cannabis use.

📗 Note: The diagram’s a glimmer; the book is the lighthouse. Sail toward wisdom here 📗

Cover of The Doctor-Approved Cannabis Handbook featuring a green medical plus symbol
Unlock the world of medical cannabis with The Doctor-Approved Cannabis Handbook.

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