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
CautionEmerging evidence
What is happening. Melatonin can add to tapentadol-related sedation, dizziness, falls, and respiratory depression risk.
Mechanism. Additive CNS depressant effects can worsen opioid impairment and breathing risk.
Recommendation. Avoid unsupervised use, especially during initiation, dose increases, sleep apnea, lung disease, older age, or other sedatives.
Stack Score
How it moves the number.
Effect on the composite score
If both Melatonin and Tapentadol are in the same stack, this pair applies −5 to your Stack Score (per scored caution 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- 1Dowell D et al. CDC Clinical Practice Guideline for Prescribing Opioids for Pain. MMWR. 2022.Needs sourceNo link