Quinidine; Quinine/Aluminum and Magnesium Antacids 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:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Taking quinidine with an antacid may make your kidneys eliminate quinidine more slowly.Taking quinine with an antacid may prevent your body from absorbing quinine.Some vitamins may contain "hidden" antacids such as some forms of magnesium.

What might happen:

Your blood level of quinidine may increase and cause toxic effects.Your blood level of quinine may decrease and it may not work as well.

What you should do about this interaction:

Let your healthcare professional (e.g. doctor or pharmacist) know that you are taking these medicines together.If you are taking quinidine and you experience a rash, headache, lightheadedness, dizziness, irregular heartbeat, fast or slow heartbeat, or ringing in the ears, contact your doctor as soon as possible. If you experience nausea, vomiting, diarrhea, stomach discomfort, or blurred vision that is continuous or bothersome, contact your healthcare professional (e.g. doctor or pharmacist). Your doctor may want to adjust the dose of your medicine.If you are taking quinine, talk to your healthcare professional about alternatives to your antacid.Your healthcare professionals may already be aware of this 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.Gerhardt RE, Knouss RF, Thyrum PT, Luchi RJ, Morris JJ Jr. Quinidine excretion in aciduria and alkaluria. Ann Intern Med 1969 Nov;71(5):927-33.
  • 2.Zinn MB. Quinidine intoxication from alkali ingestion. Tex Med 1970 Dec; 66(12):64-6.
  • 3.Gibaldi M, Grundhofer B, Levy G. Effect of antacids on pH of urine. Clin Pharmacol Ther 1974 Sep;16(3):520-5.
  • 4.Romankiewicz JA, Reidenberg M, Drayer D, Franklin JE Jr. The noninterference of aluminum hydroxide gel with quinidine sulfate absorption: an approach to control quinidine-induced diarrhea. Am Heart J 1978 Oct;96(4):518-20.
  • 5.Qualaquin (quinine sulfate) US prescribing information. Sun Pharmaceutical Industries, Inc. August, 2019.
  • 6.Hurwitz A. The effects of antacids on gastrointestinal drug absorption. II. Effect on sulfadiazine and quinine. J Pharmacol Exp Ther 1971 Dec; 179(3):485-9.

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.

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.