Hydroxychloroquine can cause dangerous effects on your heart, especially if you also use certain other medicines including the antibiotic azithromycin (Z-Pak). Seek emergency medical attention if you have fast or pounding heartbeats and sudden dizziness (like you might pass out).
Taking hydroxychloroquine long-term or at high doses may cause irreversible damage to the retina of your eye that could progress to permanent vision problems.
Stop taking hydroxychloroquine and call your doctor at once if you have blurred vision, trouble focusing, distorted vision, blind spots, trouble reading, changes in your color vision, increased sensitivity to light.
Before taking this medicine
You should not use hydroxychloroquine if you are allergic to hydroxychloroquine or chloroquine.
High doses or long-term use of hydroxychloroquine may cause irreversible damage to your retina (the membrane layer inside your eye that helps produce vision). This could progress to permanent vision problems. The risk of retinal damage is higher in people with pre-existing eye problems, kidney disease, or people who also take tamoxifen.
To make sure hydroxychloroquine is safe for you, tell your doctor if you have ever had:
vision changes or damage to your retina caused by an anti-malaria medication;
heart disease, heart rhythm disorder (such as long QT syndrome);
diabetes;
a stomach disorder;
an allergy to quinine;
liver or kidney disease;
psoriasis;
alcoholism;
porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system); or
a genetic enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD) deficiency.
Tell your doctor if you are pregnant or plan to become pregnant. Malaria is more likely to cause serious illness or death in a pregnant woman. Having malaria during pregnancy may also increase the risk of miscarriage, stillbirth, premature delivery, and low birth weight.
It is not known whether hydroxychloroquine will harm an unborn baby. If you are pregnant, ask your doctor about the risks of traveling to areas where malaria is common (such as Africa, South America, and Southern Asia).
It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.
Hydroxychloroquine is not approved for treating lupus or rheumatoid arthritis in anyone younger than 18 years old.
How should I take hydroxychloroquine?
Take hydroxychloroquine exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.
Take hydroxychloroquine with a meal or a glass of milk unless your doctor tells you otherwise.
To treat lupus or arthritis, hydroxychloroquine is usually taken daily.
To prevent malaria: Hydroxychloroquine is usually taken once per week on the same day each week. Start taking the medicine 2 weeks before entering an area where malaria is common. Keep taking the medicine during your stay and for at least 4 weeks after you leave the area.
To treat malaria: Hydroxychloroquine is usually given as one high dose followed by smaller doses during the next 2 days in a row.
Use this medicine for the full prescribed length of time, even if your symptoms quickly improve.
Call your doctor as soon as possible if you have been exposed to malaria, or if you have fever or other symptoms of illness during or after a stay in an area where malaria is common.
Use protective clothing, insect repellents, and mosquito netting around your bed to further prevent mosquito bites that could cause malaria.
No medication is 100% effective in treating or preventing all types of malaria. Talk with your doctor if you have fever, vomiting, or diarrhea during your treatment.
While using hydroxychloroquine, you may need frequent medical tests and vision exams.
Store at room temperature away from moisture, heat, and light.
