⚠️ Mechanism
St Johns Wort is a moderate inducer of CYP2C19, which increases metabolism of CYP2C19 substrates, potentially reducing their plasma concentrations and therapeutic efficacy.
📋 Effect
Reduced plasma levels of propranolol (beta-blockers), potentially leading to therapeutic failure.
💊 Management
Monitor for reduced efficacy of propranolol. Dose adjustment may be necessary. Consider alternative supplement or consult healthcare provider.
Plain Language Summary
This combination can be moderately risky because St. John's Wort may cause your body to process beta blockers faster than usual. This can lead to lower levels of the medication in your system, potentially making it less effective.
Source
Flockhart CYP450 Table (drug-interactions.medicine.iu.edu)
Supporting Research
The effect of Hypericum perforatum on postmenopausal symptoms and depression: A randomized controlled trial
Hypericum extract LI 160 and fluoxetine in mild to moderate depression: a randomized, placebo-controlled multi-center study in outpatients
[Hypericum perforatum extract in treatment of mild to moderate depression. Clinical and pharmacological aspects]
Hypericum perforatum versus fluoxetine in the treatment of mild to moderate depression
Efficacy of continuation treatment with hypericum perforatum in depression
Predicting stable treatment response in patients with major depression treated with hypericum extract WS 5570/5572
Adverse Event Profile: St Johns Wort
Medical Disclaimer: This interaction record is for informational and educational purposes only and does not constitute medical advice. Drug-supplement interactions can be dangerous. Always consult your healthcare provider or pharmacist before combining any supplement with prescription medications. Do not stop or change any medication without professional guidance.