Elvitegravir, cobicistat, emtricitabine, and tenofovir and Promethazine and codeine interaction
Elvitegravir, cobicistat, emtricitabine, and tenofovir 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 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 CYP3A4 inhibitor or CYP3A4 inducer.
Avoid the use of Promethazine HCl and Codeine Phosphate Oral Solution in patients who are taking a CYP2D6 inhibitor.
From the Elvitegravir, cobicistat, emtricitabine, and tenofovir (Genvoya) label · effective 2025-02-03
…Lipid-modifying Agents: lomitapide, lovastatin, simvastatin Phosphodiesterase-5 (PDE-5) Inhibitor: sildenafil when administered as REVATIO ® for the treatment of pulmonary arterial hypertension Sedative/hypnotics: triazolam, orally administered midazolam Coadministration of GENVOYA is contraindicated with drugs that: Are highly dependent on CYP3A for clearance and for which…
Sedative/hypnotic: midazolam (oral) triazolam ↑ midazolam ↑ triazolam Coadministration with triazolam or orally administered midazolam is contraindicated due to potential for serious and/or life-threatening reactions such as prolonged or increased sedation or respiratory depression.
Dosage reduction for midazolam should be considered, especially if more than a single dose of midazolam is administered. buspirone zolpidem With other sedative/hypnotics, dose reduction may be necessary and clinical monitoring is recommended.
Other benzodiazepines: e.g., parenterally administered midazolam clorazepate diazepam estazolam flurazepam ↑ sedatives/hypnotics Triazolam and orally administered midazolam are extensively metabolized by CYP3A.
Narcotic Analgesics: buprenorphine/ naloxone ↑ buprenorphine ↑ norbuprenorphine ↓ naloxone No dosage adjustment of buprenorphine/naloxone is required upon coadministration with GENVOYA.
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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.