Carbamazepine and Lenacapavir interaction
Carbamazepine and Lenacapavir: 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 Lenacapavir (Sunlenca) label · effective 2026-08-27
Concomitant administration of SUNLENCA with carbamazepine or phenytoin is contraindicated.
Concomitant administration of SUNLENCA with strong CYP3A inducers is contraindicated due to decreased lenacapavir plasma concentrations, which may result in the loss of therapeutic effect and development of resistance to SUNLENCA [see Drug Interactions (7.1) ] .
Concomitant administration of SUNLENCA is contraindicated with strong CYP3A inducers.
Concomitant administration of SUNLENCA with strong CYP3A inducers during SUNLENCA treatment is contraindicated [see Contraindications (4) ] .
Concomitant administration of SUNLENCA with moderate CYP3A inducers during SUNLENCA treatment is not recommended.
From the Carbamazepine (EQUETRO) label · effective 2025-08-19
It may be necessary to reduce the EQUETRO dose if used concomitantly with inhibitors of CYP3A4 and/or epoxide hydrolase.
Cytochrome (CYP) 3A4 inhibitors, epoxide hydrolase inhibitors, CYP3A4 inducers, drugs metabolized by CYP1A2 or CYP3A4 (oral contraceptives, delavirdine, nefazodone), phenytoin, CNS depressants, lithium, chloroquine, mefloquine ( 7.1 , 7.2 , 7.3 )
The following drugs are CYP3A4 inhibitors: Acetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole ) , cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, nefazodone, niacinamide,…
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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.