Patients should consult their physician before taking any additional prescriptions, over-the-counter medications, nutritional supplements or herbal medications.

Kaolin (diarrhea drug) and magnesium trisilicate (antacid) may decrease absorption of both chloroquine and hydroxychloroquine. Chloroquine may interfere with antibody response to intradermal human diploid cell rabies vaccine. Cimetidine, which is used to treat duodenal ulcers, may reduce oral clearance and metabolism of chloroquine. Use of the cardiac drug digoxin with hydroxychloroquine may increase serum digoxin levels.