Supplement × Prescription·a conflict·Emerging evidence
St. John's Wort may induce CYP3A4 and reduce tolterodine exposure, lowering symptom control.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
What is happening. St. John's Wort may induce CYP3A4 and reduce tolterodine exposure, lowering symptom control.
Mechanism. CYP3A4 induction can lower concentrations of susceptible substrates.
Recommendation. Avoid starting or stopping without monitoring overactive bladder symptoms and adverse effects.
Effect on the composite score
If both St. John's Wort and Tolterodine are in the same stack, this pair applies −10 to your Stack Score (per scored conflict row).
The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.
Every claim on this page is cited. PMIDs link straight to PubMed.
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