Chloroquine and Cimetidine interaction
Chloroquine and Cimetidine: the Chloroquine 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 Chloroquine (Chloroquine Phosphate) label · effective 2026-01-13
Concomitant use of cimetidine should be avoided.
Cimetidine: Cimetidine can inhibit the metabolism of chloroquine, increasing its plasma level.
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.