Azithromycin and Clarithromycin interaction
Azithromycin and Clarithromycin: 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 Azithromycin (Zithromax) label · effective 2026-07-24
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.
However, drug interactions have been observed with other macrolide products.
From the Clarithromycin label · effective 2026-01-01
Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp.
Clarithromycin and other macrolides are known to inhibit CYP3A.
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.