Hydroxychloroquine

Brand names

• Dermoplast
• Plaquenil

Usage

To prevent and treat malaria caused by specific strains of plasmodia (the parasite that causes malaria) that are chloroquine-sensitive, but when chloroquine is not available. It is also used to treat rheumatoid arthritis and lupus.

How it works

Hydroxychloroquine is poisonous to the malarial parasite. For rheumatoid arthritis and lupus, it may suppress the release of certain chemicals that cause inflammation.

Side effects

Serious

Blurred or altered vision; blood problems, including low white blood cell count (sore throat, fever); anemia (fatigue, weakness); and low platelet count (easy bleeding and bruising). Such side effects are extremely rare; call your doctor immediately if they occur.

Common

No common side effects have been reported.

Less common

Diarrhea, loss of appetite, headache, stomach cramps or pain, nausea or vomiting, itching, dizziness, fatigue, confusion, loss or bleaching of hair, skin rash. Also blue-black discoloration of the skin, the inside of the mouth, or the fingernails.

Possible interactions

Other medicaments:

Hydroxychloroquine may increase the effects of:

• aurothioglucose (Solganol), which increases risk of blood problems.
• digoxin (Lanoxin) and increase its toxic potential.
• penicillamine (Cuprimine, Depen) and increase its toxic potential.

The following medicaments may increase the effects of hydroxychloroquine:



• cimetidine (Tagamet).

The following medicaments may decrease the effects of hydroxychloroquine:



• magnesium salts and antacids.

Herbal medicines or minerals:

Caution: St. John's wort may also cause extreme reactions to the sun. Additive photosensitivity may be possible. Hay flower, mistletoe herb and white mustard seed carry German Commission E monograph indications for arthritis, but have not been studied with this medicine. Talk to your doctor before combining any herbal with hydroxychloroquine.

Alcohol:

Use sparingly to minimize stomach irritation.

Exposure to sun:

Use caution until sensitivity has been determined. Closely related medicaments of this class may cause photosensitivity.

Discontinuation:

This medicament should be stopped and prompt evaluation should be made if any of the following develop-changes in vision or hearing, seizures, unusual muscle weakness, indications of infection (fever, sore throat, etc.), abnormal bruising or bleeding.