Before taking hydroxychloroquine,
tell your doctor and pharmacist if you are allergic to hydroxychloroquine, chloroquine, primaquine, quinine, or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription drugs, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention acetaminophen (Tylenol, others); azithromycin (Zithromax); cimetidine (Tagamet); cyclosporine (Gengraf, Neoral, Sandimmune); digoxin (Lanoxin), insulin and oral medication for diabetes; medications for seizures such as carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, Teril), phenytoin (Dilantin, Phenytek), or valproic acid (Depakene); certain medications for irregular heartbeat such as amiodarone (Pacerone); methotrexate (Trexall, Xatmep); moxifloxacin (Avelox); praziquantel (Biltricide); and tamoxifen (Nolvadex). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with hydroxychloroquine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
if you are taking antacids, take them 4 hours before or 4 hours after hydroxychloroquine. If you are taking ampicillin, take it at least 2 hours before or 2 hours after hydroxychloroquine.
tell your doctor if you have or have ever had liver disease, heart disease, a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), an irregular heartbeat, a low level of magnesium or potassium in your blood, psoriasis, porphyria or other blood disorders, G-6-PD deficiency (an inherited blood disease), dermatitis (skin inflammations), seizures, vision problems, diabetes, kidney problems, or if you drink large amounts of alcohol.
tell your doctor if you have ever had vision changes while taking hydroxychloroquine, chloroquine (Aralen), or primaquine.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking hydroxychloroquine, call your doctor.