Carbamazepine and Voriconazole interaction
Carbamazepine and Voriconazole: 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 Voriconazole label · effective 2026-06-02
Carbamazepine (CYP450 Induction) Not Studied In Vivo or In Vitro , but Likely to Result in Significant Reduction Contraindicated Long Acting Barbiturates (e.g., phenobarbital, mephobarbital) (CYP450 Induction) Not Studied In Vivo or In Vitro , but Likely to Result in Significant Reduction Contraindicated Phenytoin (CYP450 Induction) Significantly Reduced Increase…
Concomitant use of voriconazole is contraindicated with drugs and herbal products that induce CYP2C19, CYP2C9, and/or CYP3A4 and for which significantly reduced voriconazole plasma concentrations may be associated with loss of efficacy [see Drug Interactions (7) ]: • Carbamazepine • Efavirenz Concomitant use with efavirenz dosages of 400 mg every 24 hours or…
• Concomitant use with drugs and herbal products that induce CYP2C19, CYP2C9, and/or CYP3A4 and for which significantly reduced voriconazole plasma concentrations may be associated with loss of efficacy ( 4 , 7 )
Eszopiclone (CYP3A4 Inhibition) Not Studied In Vivo or In Vitro , but Drug Plasma Exposure Likely to be Increased which may Increase the Sedative Effect of Eszopiclone Dose reduction of eszopiclone is 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,…
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.