What is hydroxychloroquine?

Hydroxychloroquine is a prescription drug. It comes as an oral tablet.

Hydroxychloroquine is available as the brand-name drug Plaquenil. It’s also available in a generic version. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Hydroxychloroquine may be used as part of a combination (Azithromycin) therapy. That means you may need to take it with other drugs.

Hydroxychloroquine belongs to the family of medicines called “antimalarials” (AMs), which are also classified as disease-modifying anti-rheumatic drugs, or DMARDs. These drugs were initially used to prevent and treat malaria but are no longer used for those purposes; more effective drugs have since been developed. Today’s AMs are hydroxychloroquine, chloroquine, and quinacrine. (Quinacrine is no longer marketed in the U.S.; it can be dispensed by a compounding pharmacy, although insurance companies may not pay for it.)

The antimalarial quinine was first used to treat cutaneous lupus in 1834. Subsequent reports in 1928 and 1938 showed good results with another quinine-like drug in the treatment of both discoid and subacute cutaneous lupus. In 1941, discoid lupus patients were treated successfully with Atabrine, a compound developed in Germany in the 1920s. In the mid-1940s, both hydroxychloroquine (HCQ) and chloroquine (CQ) had been synthesized. In 1955 HCQ was shown to be effective for both systemic lupus and rheumatoid arthritis. (Wallace DJ, Hahn BH, eds. Dubois’ Lupus Erythematosus. 1997:1117.)

Why it’s used

Hydroxychloroquine is used to prevent or treat malaria caused by mosquito bites. The United States Center for Disease Control provides updated guidelines and travel recommendations for the prevention and treatment of malaria in different parts of the world. Discuss the most recent information with your doctor before traveling to areas where malaria occurs.

This medication is also used to treat certain auto-immune diseases (lupus, rheumatoid arthritis). It belongs to a class of medications known as disease-modifying antirheumatic drugs (DMARDs). It can reduce skin problems in lupus and prevent swelling/pain in arthritis.

Precautions

Before taking hydroxychloroquine, tell your doctor or pharmacist if you are allergic to it, or chloroquine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: a certain enzyme problem (glucose-6-phosphate dehydrogenase deficiency-G6PD), vision/eye problems, hearing problems, kidney disease, liver disease, regular alcohol use/abuse, skin problems (such as psoriasis), a certain blood disorder (porphyria), seizures.

If you have diabetes, this product may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of low blood sugar (see Side Effects section). Your doctor may need to adjust your diabetes medication, exercise program, or diet.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you dizzier. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). Alcohol can also increase your risk of liver problems while you are taking this drug.

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Benefits

Research into the wide-ranging effects of hydroxychloroquine has revealed many important benefits in the treatment of lupus; it must be noted that these benefits may be less effective in people who smoke (Arthritis Care & Research 2010; 62:393–400). Benefits include:

  • The decrease in the number of disease flares.
  • The decrease in damage from the disease over time.
  • Ability to delay the absorption of ultraviolet light.
  • Reduction in the number of antigen-presenting cells in the skin.

A systematic review published in Annals of Rheumatic Diseases in January 2009 looked at data on the clinical efficacy and side effects of AMs in systemic lupus, from randomized controlled clinical trials and observational studies, in 95 articles published between 1982 and 2007. The authors found:

  • Strong evidence, especially with HCQ, of decreased lupus activity during pregnancy without harm to the fetus.
  • Strong evidence of prevention of disease flares.
  • Strong evidence of increased long-term survival.
  • Moderate evidence of protection against irreversible organ damage, thrombosis (blood clot formation), and bone mass loss.

Overdose

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canadian residents can call a provincial poison control center. Symptoms of overdose may include fast/irregular heartbeat, fainting, slow/shallow breathing, seizures.

Notes

Do not share this medication with others.

Lab and/or medical tests (such as eye exams, reflex tests, liver function, EKG, complete blood counts) should be done if you are taking hydroxychloroquine for a long time. Keep all medical and lab appointments. Consult your doctor for more details.

When traveling in an area at risk for malaria, use protective clothing, insect repellent, and bed nets. Remain indoors or in well-screened areas when possible. If you are taking this medication to prevent or treat malaria, use it for your current travel or condition only. Do not use it later to prevent or treat another infection unless your doctor tells you to.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at a regular time. Do not double the dose to catch up.

Storage

Store at room temperature away from moisture and light. Do not store in the bathroom. Keep all medications away from children and pets.