Azithromycin and Fluconazole interaction

Azithromycin and Fluconazole: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Azithromycin (Zithromax) label · effective 2026-07-24

Major

This risk which can be fatal should be considered in patients with certain cardiovascular disorders including known QT prolongation or history torsades de pointes, those with proarrhythmic conditions, and with other drugs that prolong the QT interval.

Warnings and precautionsby drug classView label on DailyMed

From the Fluconazole label · effective 2026-04-02

Major

Coadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole.

Contraindicationsby drug classView label on DailyMed
Moderate

Azithromycin An open-label, randomized, three-way crossover study in 18 healthy subjects assessed the effect of a single 1200 mg oral dose of azithromycin on the pharmacokinetics of a single 800 mg oral dose of fluconazole as well as the effects of fluconazole on the pharmacokinetics of azithromycin.

Drug interactionsnames AzithromycinView label on DailyMed
No interaction

There was no significant pharmacokinetic interaction between fluconazole and azithromycin.

Drug interactionsnames AzithromycinView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

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Not 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.