MAJOR — Use With Caution
DANGEROUS — additive respiratory depression
Evidence level: STRONG
Benadryl with methadone is dangerous — additive breathing suppression.
Additive CNS and respiratory depression from antihistamine sedation + full opioid agonist.
Avoid. Use non-sedating antihistamines.
Take Methadone exactly as prescribed — set alarms for scheduled doses. Diphenhydramine follows its normal schedule. Opioids slow GI transit, which can affect absorption of other medications. Take with food if nausea occurs. Never combine with alcohol.
High methadone dose, concurrent alcohol, elderly
Extreme drowsiness, respiratory depression, death
Do not take OTC sedating antihistamines on methadone.
Opioid combinations carry serious risks including respiratory depression. Talk to your pain management specialist about non-opioid alternatives: physical therapy, NSAIDs (if appropriate), nerve blocks, or non-sedating supplements like PEA (palmitoylethanolamide) or curcumin for inflammation.
Benadryl with methadone is dangerous — additive breathing suppression.
Take Methadone exactly as prescribed — set alarms for scheduled doses. Diphenhydramine follows its normal schedule. Opioids slow GI transit, which can affect absorption of other medications. Take with food if nausea occurs. Never combine with alcohol.
Extreme drowsiness, respiratory depression, death
Opioid combinations carry serious risks including respiratory depression. Talk to your pain management specialist about non-opioid alternatives: physical therapy, NSAIDs (if appropriate), nerve blocks, or non-sedating supplements like PEA (palmitoylethanolamide) or curcumin for inflammation.
Do not take OTC sedating antihistamines on methadone.
Or browse the full interaction database (121,000+ pairs).