Chloroquine; Hydroxychloroquine/Cimetidine Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Medical warning:
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your kidneys may not be able to properly remove chloroquine or hydroxychloroquine from your blood.
What might happen:
The amount of chloroquine or hydroxychloroquine in your blood may increase and result in more side effects than expected, including an irregular heartbeat which may be life-threatening.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together, and if you have muscle weakness or symptoms of low blood sugar (shaking, sweating, hunger). Let your doctor know right away if you notice any visual changes, an irregular heartbeat or have any dizziness or fainting episodes. Your doctor may want to adjust or change your medicines.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
- 1.Aralen (chloroquine) US prescribing information. Sanofi-Aventis U.S. LLC October, 2018.
- 2.Plaquenil (hydroxychloroquine sulfate) US prescribing information. Concordia Pharmaceuticals Inc. December, 2023.
- 3.Drew BJ, Ackerman MJ, Funk M, Gibler WB, Kligfield P, Menon V, Philippides GJ, Roden DM, Zareba W. Prevention of torsade de pointes in hospital settings: a scientific statement from the American Heart Association and the American College of Cardiology Foundation. J Am Coll Cardiol 2010 Mar 2;55(9):934-47.
- 4.Ette EI, Brown-Awala EA, Essien EE. Chloroquine elimination in humans: effect of low-dose cimetidine. J Clin Pharmacol 1987 Oct;27(10):813-6.
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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.