⚠️

Carbamazepine + St. Johns Wort

MAJOR — Use With Caution

DANGEROUS — unpredictable additive enzyme induction

Evidence level: MODERATE

What this interaction means

Combining two potent enzyme inducers creates unpredictable drug interactions that could affect seizure control.

How it works (mechanism)

Both are CYP3A4 inducers. Additive enzyme induction may cause unpredictable effects on carbamazepine and other drug metabolism.

Practical advice

Avoid combining. St. Johns Wort should not be used with antiepileptic drugs.

Timing

Take Carbamazepine at exact consistent times — seizure control depends on stable blood levels. St. Johns Wort can be taken at a separate meal. Some botanicals (evening primrose, borage) may lower seizure threshold. St. John's Wort can dramatically reduce antiepileptic levels via CYP enzyme induction.

Risk factors

Epilepsy, concurrent medications affected by CYP induction

Symptoms to watch for

Seizure breakthrough, unpredictable drug levels

What to tell your doctor

Do not use St. Johns Wort with antiepileptics.

Safer alternatives

Antiepileptic drug levels are sensitive to enzyme inducers and inhibitors. Discuss any changes with your neurologist before adding new substances. Safer supplement options: magnesium, omega-3s, and B vitamins are generally well-tolerated alongside seizure medications.

Frequently asked questions

Can I take Carbamazepine and St. Johns Wort together?

Combining two potent enzyme inducers creates unpredictable drug interactions that could affect seizure control.

When should I take Carbamazepine vs St. Johns Wort?

Take Carbamazepine at exact consistent times — seizure control depends on stable blood levels. St. Johns Wort can be taken at a separate meal. Some botanicals (evening primrose, borage) may lower seizure threshold. St. John's Wort can dramatically reduce antiepileptic levels via CYP enzyme induction.

What symptoms should I watch for if I combine Carbamazepine and St. Johns Wort?

Seizure breakthrough, unpredictable drug levels

Are there safer alternatives to combining Carbamazepine with St. Johns Wort?

Antiepileptic drug levels are sensitive to enzyme inducers and inhibitors. Discuss any changes with your neurologist before adding new substances. Safer supplement options: magnesium, omega-3s, and B vitamins are generally well-tolerated alongside seizure medications.

What should I tell my doctor about taking Carbamazepine and St. Johns Wort?

Do not use St. Johns Wort with antiepileptics.

Explore more interactions

Or browse the full interaction database (121,000+ pairs).