From the databaseWhat the row says.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
Scope
Supplement × Prescription
Last verified
June 4, 2026
ConflictModerate evidence
What is happening. St. John's Wort can induce CYP3A4 and may reduce roflumilast exposure, potentially decreasing COPD exacerbation prevention.
Mechanism. CYP3A4 induction can lower roflumilast and active metabolite exposure.
Recommendation. Avoid St. John's Wort unless the prescriber specifically approves and monitors clinical response.
Stack Score
How it moves the number.
Effect on the composite score
If both Roflumilast and St. John's Wort 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.
SourcesSources, by evidence tier.
Every claim on this page is cited. PMIDs link straight to PubMed.
Reference material
1- 1U.S. National Library of Medicine. Roflumilast Tablets US Prescribing Information. 2026.Needs sourceNo link