St Johns Wort and Theophylline

Supplement–drug interaction evidence from the TruthStack database.

SeverityCRITICAL
Evidence TierModerate
Interaction TypePHARMACODYNAMIC RISK
MechanismPHARMACOKINETIC
Last Reviewed2026-02-15

Summary

St. Johns Wort induces CYP1A2, reducing theophylline levels. Can cause loss of asthma/COPD control with life-threatening bronchospasm. Discuss with your prescriber or pharmacist.

API Reference

GET https://api.truthstack.co/v1/check?c1=st%20johns%20wort&c2=theophylline

Open, unauthenticated. Returns JSON. Developer documentation

Related Interactions

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What this page is and is not. TruthStack is an informational reference database that describes published pharmacological findings. It does not provide medical advice, diagnosis, or treatment recommendations. The information on this page reflects flags in our database and should not replace consultation with a qualified healthcare provider. Always discuss supplement-drug combinations with your prescriber or pharmacist.