Ketoconazole and Salmeterol interaction
Ketoconazole and Salmeterol: 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 Salmeterol (SEREVENT DISKUS) label · effective 2022-10-10
• Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended.
In a drug interaction trial in 20 healthy subjects, coadministration of inhaled salmeterol (50 mcg twice daily) and oral ketoconazole (400 mg once daily) for 7 days resulted in greater systemic exposure to salmeterol (AUC increased 16-fold and C max increased 1.4-fold).
Although there was no statistical effect on the mean QTc, coadministration of salmeterol and ketoconazole was associated with more frequent increases in QTc duration compared with salmeterol and placebo administration.
Drug Interactions with Strong Cytochrome P450 3A4 Inhibitors The use of strong cytochrome P450 3A4 (CYP3A4) inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with SEREVENT DISKUS is not recommended because increased cardiovascular adverse effects may occur [see Drug…
The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with SEREVENT DISKUS is not recommended because increased cardiovascular adverse effects may occur.
From the Ketoconazole label · effective 2026-07-07
Respiratory Drugs salmeterol Urological Drugs fesoterodine, sildenafil, solifenacin, tadalafil, tolterodine, vardenafil Vardenafil: A single dose of 5 mg of vardenafil should not be exceeded when coadministered with ketoconazole.
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.