Daily Dose Q&A

2026-02-09

CBD may inhibit the cytochrome P450 enzyme CYP2C19. Does that pose an issue for patients who take CBD with clopidogrel (Plavix)?

Yes. Clopidogrel requires hepatic CYP2C19 metabolism to convert to its active metabolite. In vitro data demonstrate that CBD (at concentrations achieved with CBD doses of 300-1,500 mg/day in humans) may significantly inhibit CYP2C19 activity. Therefore, co-administration may reduce clopidogrel's antiplatelet efficacy and increase the risk of cardiovascular events, especially in individuals with recent coronary stent placement. Clinicians should consider monitoring for signs of reduced clopidogrel activity, such as recurrent angina, thrombosis, or stent occlusion or consider alternative antiplatelet agents which are not dependent on CYP2C19 for bioactivation.

Brown, J. D., & Winterstein, A. G. (2019). Potential adverse drug events and drug-drug interactions with medical and consumer cannabidiol (CBD) use. Journal of Clinical Medicine, 8(7), 989. https://doi.org/10.3390/jcm8070989 Greger, J., Bates, V., Mechtler, L., & Gengo, F. (2020). A review of cannabis and interactions with anticoagulant and antiplatelet agents. Journal of Clinical Pharmacology, 60(4), 432-438. https://doi.org/10.1002/jcph.1557 Jiang, R., Yamaori, S., Takeda, S., Yamamoto, I., & Watanabe, K. (2013). Cannabidiol is a potent inhibitor of the catalytic activity of cytochrome P450 2C19. Drug Metabolism and Pharmacokinetics, 28(4), 332-338. https://doi.org/10.2133/dmpk.DMPK-12-RG-129

2026-02-06

Does cannabis impact the health of the placenta?

Cannabis use during pregnancy may negatively impact the health of the placenta, as cannabinoids may alter uterine/placental blood flow. There's an increase in placental resistance and a reduction placental circulation.

El Marroun, H., Tiemeier, H., Steegers, E. A., et al. (2010). A prospective study on intrauterine cannabis exposure and fetal blood flow. Early Human Development, 86(4), 231-236. https://doi.org/10.1016/j.earlhumdev.2010.03.001. and Tortoriello, G., Morris, C. V., Alpar, A., et al. (2014). Miswiring the brain: _9-tetrahydrocannabinol disrupts cortical development by inducing an SCG10/stathmin-2 degradation pathway. EMBO Journal, 33(7), 668-685. https://doi.org/10.1002/embj.201386035

2026-02-05

What are the typical signs and symptoms of pediatric intoxication?

"Symptoms are usually nonspecific and include manifestations such as central nervous system depression (lethargy, coma), confusion, agitation, and ataxia. Nausea and vomiting, conjunctival hyperemia, mydriasis, tremors, speech difficulties, and behavioral disturbances are common. In episodes of severe intoxication, bradycardia, hypotension, convulsions, and respiratory depression have been reported, and may require orotracheal intubation." (Fradera) Although respiratory depression is not typical in adults, it may be present in pediatric patients.

Fradera, A. S., Campos, L. S., Profumo, A. D., et al. (2024). Accidental cannabis intoxication with an unexpected outcome. Emergencia Pediatricas, 3(2), 91-93.

2026-02-04

At what age is the human brain fully developed?

"The frontal lobes, the area of the brain responsible for 'executive functions' such as planning, working memory, and impulse control, are among the last areas of the brain to mature. They may not be fully developed until about age 25 years old. So, although many U.S. states have legalized recreational cannabis use for adults aged 21 years and older, it is important to note that the human brain is not fully developed, and individuals in their 20's may not realize the potentially significant long-term consequences of consuming cannabis.

Johnson, S. B., Blum, R. W., & Giedd, J. N. (2009). Adolescent maturity and the brain: The promise and pitfalls of neuroscience research in adolescent health policy. Journal of Adolescent Health, 45(3), 216-221.

2026-02-03

Is the endocannabinoid system present and active during fetal development?

The endocannabinoid system (ECS) plays a significant role in fetal development. Cannabinoid receptors and the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), appear around gestational week 19 in humans and are thought to influence early behavioral and neurodevelopmental processes. Evidence from animal studies demonstrates that CB1 receptors are functional during fetal development and contribute to the formation, growth, migration, and wiring of neuronal networks. Studies indicate that prenatal THC exposure can disrupt the maturation of dopamine, opioid, glutamate, and GABAergic neurotransmitter systems within brain regions involved with reward and motivation.

Jansson, L. M., et al. (2018). Perinatal marijuana use and the developing brain. JAMA, 320(6), 545-546. https://doi.org/10.1001/jama.2018.8401 Malach, M., Kovalchuk, I., & Kovalchuk, O. (2022). Medical cannabis in pediatric oncology: Friend or foe? Pharmaceuticals, 15(3), 359. https://doi.org/10.3390/ph15030359