Drug Interaction Between CBD Oil and Ketorolac
There is a theoretical but low-probability risk of drug interaction between CBD oil and ketorolac, primarily through CBD's inhibition of cytochrome P450 enzymes, though ketorolac itself does not rely on these enzymes for metabolism and shows no evidence of inducing or inhibiting hepatic enzymes. 1, 2
Mechanism of Potential Interaction
CBD inhibits several cytochrome P450 enzymes (specifically CYP3A4, UGT1A9, UGT2B7, CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2C19), which creates theoretical potential for drug-drug interactions through altered metabolism 1. However, ketorolac is highly protein-bound (99.2%) and shows no evidence of inducing or inhibiting hepatic enzymes capable of metabolizing itself or other drugs 2. Ketorolac is largely metabolized in the liver through hydroxylation and conjugation, with 92% excreted renally 2.
Clinical Significance Assessment
The 2024 ASCO guideline on cannabis and cannabinoids reports a generally low probability of clinically relevant drug interactions with cannabis/cannabinoids for most medications 1. The guideline specifically identifies only three high-risk interactions:
- Very high risk: Warfarin
- High risk: Buprenorphine and tacrolimus
Ketorolac is not mentioned among high-risk interactions 1.
Additive Side Effect Considerations
While direct pharmacokinetic interaction is unlikely, consider these overlapping effects:
Gastrointestinal effects: Both CBD and ketorolac can cause GI symptoms. Ketorolac carries significant risk for serious GI ulceration and bleeding 2. CBD commonly causes GI discomfort 1.
Hepatotoxicity: CBD presents dose-dependent hepatotoxicity risk, with nearly 6-fold increased liver enzyme elevation at doses >300 mg/day 1. Monitor liver enzymes if using CBD concurrently with ketorolac, particularly since ketorolac should be discontinued if abnormal liver tests persist or worsen 2.
CNS effects: CBD can cause dizziness, drowsiness, and sedation 1, which may be additive with any CNS effects from pain or ketorolac use.
Clinical Recommendations
You can use CBD oil and ketorolac together with appropriate monitoring, but:
- Monitor for enhanced GI side effects (nausea, dyspepsia, abdominal pain) given both agents affect the GI tract
- Check baseline and periodic liver enzymes if CBD dose exceeds 300 mg/day 1
- Start CBD at low doses and titrate slowly to minimize adverse effects 1
- Avoid high-fat meals with CBD as this significantly increases cannabinoid absorption and may exacerbate side effects 1
- Limit ketorolac duration to the shortest effective course (typically ≤5 days) as per standard NSAID safety practices
Important Caveat
The paucity of clinical data on cannabis/cannabinoid drug interactions remains a significant concern, and clinicians often cannot provide scientifically supported answers about potential interactions 1. The lack of standardization in CBD products further complicates risk assessment, as effects cannot be extrapolated between different preparations 1.