Erythromycin and Quinine interaction
Erythromycin and Quinine: the Quinine prescribing label flags 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 Quinine (QUININE SULFATE) label · effective 2025-10-31
Fatal torsades de pointes was reported in an elderly patient who received concomitant quinine, erythromycin, and dopamine.
The use of macrolide antibiotics such as erythromycin should be avoided in patients receiving quinine sulfate.
Therefore, concomitant administration of macrolide antibiotics such as erythromycin or troleandomycin with quinine sulfate should be avoided [see WARNINGS AND PRECAUTIONS ( 5.3 )] .
In a crossover study (N=10), healthy subjects who received a single oral 500 mg dose of quinine sulfate with erythromycin (600 mg every 8 hours for four days) showed a decrease in quinine oral clearance (CL/F), an increase in half-life, and a decreased metabolite (3-hydroxyquinine) to quinine AUC ratio, as compared to when quinine was given with placebo.
Although a causal relationship between a specific drug and the arrhythmia was not established in this case, erythromycin is a CYP3A4 inhibitor and has been shown to increase quinine plasma levels when used concomitantly.
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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.