Working draft — Scientific review: pending | Regulatory review: pending | Not for external clinical or promotional use without independent verification
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PrescriberLast reviewed: April 2026

Drug Interactions, Safety and Pharmacovigilance

Provide practical safety training.

Learning Objectives

Identify CYP2C19, CYP3A4 and UGT relevance
Identify sedative and antiepileptic interactions
Understand valproate/liver risk
Understand anticoagulant caution
Understand psychiatric risks of THC
Understand pregnancy/lactation and driving cautions
Know the adverse-event reporting process

Core Content

Both CBD and THC are pharmacologically active substances with clinically relevant interaction profiles.

They are not inert supplements. They require the same pharmacovigilance attention as any other medicine.

Key Takeaways

  • 1CBD and THC have clinically significant drug interaction profiles
  • 2CYP3A4, CYP2C19, and UGT pathways are key
  • 3Clobazam, valproate, and warfarin are high-risk combinations
  • 4All adverse reactions should be reported via Yellow Card
  • 5Internal pharmacovigilance records are essential

Knowledge Check

Q1. Which enzyme pathway is most relevant for CBD drug interactions?

Downloadable Tools

Drug interaction quick-reference

RED/AMBER/GREEN severity-coded interaction card

card

Safety-monitoring checklist

Checklist for safety monitoring at each visit

checklist

Adverse-event form

Standardised adverse event documentation form

form

Pharmacovigilance SOP one-pager

Standard operating procedure for adverse event reporting

sop

Tools are provided as templates for clinical practice. Adapt to your clinic's specific requirements.

References

  1. [1]Epidyolex SmPC. Drug interaction section.
  2. [2]Gaston TE, et al. Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia. 2017;58(9):1586-1592.
  3. [3]MHRA. Yellow Card scheme. https://yellowcard.mhra.gov.uk/
Module 7: Dosing & MonitoringModule 9: Clinical Pathways

This material is educational and non-promotional. It does not constitute medical advice, prescribing advice, or a recommendation to use any medicine. Any use of an unlicensed medicine requires patient-specific clinical justification, informed consent, monitoring, pharmacovigilance and compliance with applicable regulatory requirements.