Is it safe to take CBD (Cannabidiol) oil with lamotrigine (Lamictal)?

CBD Oil and Lamotrigine: Safety and Interaction Considerations

Caution is warranted when using CBD oil with lamotrigine due to potential drug interactions, though no direct evidence shows a significant interaction between these specific agents.

Potential Interactions

Pharmacokinetic Considerations

• No direct evidence demonstrates a significant interaction between CBD oil and lamotrigine specifically
• However, CBD is known to inhibit several cytochrome P450 enzymes (CYP3A4 and CYP2C19) that may be involved in lamotrigine metabolism 1
• Unlike some other anticonvulsants (phenytoin, carbamazepine, phenobarbital), lamotrigine does not appear to have significant interactions with cannabinoids based on available evidence 2, 3

Clinical Evidence

• The 2017 HIVMA guidelines note that lamotrigine is not recommended for HIV-associated neuropathic pain but do not specifically mention interactions with CBD 2
• Medical guidelines acknowledge that no drug interactions have been reported between lamotrigine and CBD in epileptic patients 2

Safety Considerations

CBD-Related Risks

• CBD can cause adverse effects including:
  • Transaminase elevations (liver enzyme abnormalities)
  • Sedation
  • Sleep disturbances
  • Potential for drug-drug interactions 1
• High doses of CBD (≥300 mg/day) may cause reversible liver enzyme abnormalities 2

Monitoring Recommendations

• If using both medications:
  1. Monitor for signs of increased sedation or dizziness
  2. Consider periodic liver function tests, especially with higher CBD doses
  3. Watch for changes in seizure control or mood stability if lamotrigine is being used for epilepsy or bipolar disorder

Special Populations

Cancer Patients

• The 2024 ASCO guidelines caution about CBD use with immunotherapy but do not specifically mention interactions with lamotrigine 2
• For cancer patients, quality-controlled CBD products may be considered for refractory nausea/vomiting, but doses ≥300 mg/day are not recommended due to liver enzyme concerns 2

Patients with Epilepsy

• No specific contraindication exists for using lamotrigine with CBD in epilepsy patients
• In fact, some patients may be prescribed both medications intentionally for seizure control

Practical Recommendations

1. Start with low doses of CBD if adding to established lamotrigine therapy
2. Monitor for side effects including sedation, dizziness, and cognitive changes
3. Consider periodic liver function tests when using CBD, especially at higher doses
4. Consult with the prescribing physician before adding CBD to a lamotrigine regimen
5. Be cautious with CBD products as they vary widely in quality and actual CBD/THC content 4

If discontinuation of either agent becomes necessary, remember that lamotrigine should be tapered gradually (typically over 4 weeks) to minimize withdrawal symptoms and seizure risk 5.