Naltrexone and bupropion and Promethazine and codeine interaction
Naltrexone and bupropion and Promethazine and codeine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Naltrexone and bupropion (Contrave Extended-Release) label · effective 2025-11-10
…limited to, WELLBUTRIN, WELLBUTRIN SR, WELLBUTRIN XL, APLENZIN and ZYBAN) Bulimia or anorexia nervosa, which increase the risk for seizure [see Warnings and Precautions (5.3) ] Chronic opioid or opiate agonist (e.g., methadone) or partial agonists (e.g., buprenorphine) use, or acute opiate withdrawal [see Warnings and Precautions (5.4) and Drug Interactions (7.2)…
…Administration (2.1) and Clinical Pharmacology (12.3) ] if a dose is missed, a patient should wait until the next scheduled dose to resume the regular dosing schedule 5.4 Patients Receiving Opioid Analgesics Vulnerability to Opioid Overdose: CONTRAVE should not be administered to patients receiving chronic opioids, due to the naltrexone component, which is an opioid receptor…
An attempt by a patient to overcome any naltrexone opioid blockade by administering large amounts of exogenous opioids is especially dangerous and may lead to a fatal overdose or life-threatening opioid intoxication (e.g., respiratory arrest, circulatory collapse).
In patients requiring intermittent opiate treatment, CONTRAVE therapy should be temporarily discontinued and lower doses of opioids may be needed.
From the Promethazine and codeine (Promethazine Hydrochloride and Codeine Phosphate) label · effective 2025-12-18
Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex, requiring careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine.
Avoid the use of Promethazine HCl and Codeine Phosphate Oral Solution in patients who are taking a CYP3A4 inhibitor, CYP3A4 inducer, or 2D6 inhibitor [ see Warnings and Precautions (5.9) , Drug Interactions (7.1 , 7.2 , 7.3 ) ].
The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex, requiring careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine.
Avoid the use of Promethazine HCl and Codeine Phosphate Oral Solution in patients who are taking a CYP2D6 inhibitor.
Avoid the use of Promethazine HCl and Codeine Phosphate Oral Solution in patients who are taking inhibitors of CYP2D6.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.