Hydrocodone and chlorpheniramine and Nevirapine interaction
Hydrocodone and chlorpheniramine and Nevirapine: 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 Hydrocodone and chlorpheniramine (Hydrocodone Polistirex and Chlorpheniramine Polistirex extended-release) label · effective 2025-06-26
In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in hydrocodone plasma concentration.
Concomitant use with CYP3A4 inhibitors (or discontinuation of CYP3A4 inducers) can result in a fatal overdose of hydrocodone.
Avoid the use of Hydrocodone Polistirex and Chlorpheniramine Polistirex in patients who are taking CYP3A4 inducers.
Similarly, discontinuation of a CYP3A4 inducer, such as rifampin, carbamazepine, and phenytoin, in Hydrocodone Polistirex and Chlorpheniramine Polistirex-treated patients may increase hydrocodone plasma concentrations and prolong opioid adverse reactions.
Concomitant use of Hydrocodone Polistirex and Chlorpheniramine Polistirex with CYP3A4 inducers or discontinuation of an CYP3A4 inhibitor could decrease hydrocodone plasma concentrations, decrease opioid efficacy or, possibly, lead to a withdrawal syndrome in a patient who had developed physical dependence to hydrocodone.
From the Nevirapine label · effective 2026-07-15
Other Agents Analgesics: Methadone ↓ Methadone Methadone levels were decreased; increased dosages may be required to prevent symptoms of opiate withdrawal.
Opiate Agonists: Fentanyl Plasma concentrations may be decreased.
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.