Quinine and Rifampin interaction
Quinine and Rifampin: 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 Quinine (QUININE SULFATE) label · effective 2025-10-31
Avoid concomitant use with rifampin.
Concomitant Use of Rifampin Treatment failures may result from the concurrent use of rifampin with quinine sulfate, due to decreased plasma concentrations of quinine, and concomitant use of these medications should be avoided [see DRUG INTERACTIONS ( 7.1 )] .
Therefore the concomitant administration of rifampin with quinine sulfate should be avoided [see WARNINGS AND PRECAUTIONS ( 5.4 )] .
In healthy subjects (N=9) who received a single oral 600 mg dose of quinine sulfate after 2 weeks of pretreatment with rifampin 600 mg/day, the mean quinine AUC and C max decreased by 85% and 55%, respectively.
Antiepileptics (AEDs) (Carbamazepine, Phenobarbital, and Phenytoin) Carbamazepine, phenobarbital, and phenytoin are CYP3A4 inducers and may decrease quinine plasma concentrations if used concurrently with quinine sulfate.
From the Rifampin label · effective 2026-05-05
Quinine Prevention or Management : Avoid concomitant use Decrease AUC by 75%-85% Telithromycin Decrease AUC by 86% Theophylline Decrease exposure by 20%-40% Effect of Other Drugs on Rifampin Concomitant antacid administration may reduce the absorption of rifampin.
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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.