Hydroxychloroquine (Plaquenil)


Hydroxychloroquine (Plaquenil) is a disease-modifying anti-rheumatic drug (DMARD). It can decrease the pain and swelling of arthritis which can prevent joint damage leading to long-term disability. Hydroxychloroquine is in a class of medications that was first used to prevent and treat malaria but today is the standard drug in lupus. It can be used in many other autoimmune diseases. It is not fully clear of its mechanism of action, but the current thought is that it interferes with communication in the immune system.

How to Take It

Hydroxychloroquine comes in an oral tablet. Adult dosing for rheumatic diseases ranges from 200 mg to 400 mg per day (typically 5 mg/kg, maximum 400 mg daily). In some cases, higher doses are used. It can be taken as a single daily dose or in 2 divided doses if taking more than one tablet. It is recommended to be taken with food as some of the gastrointestinal side effects can be alleviated with food and fats. Symptoms can start to improve in one to two months, but it may take up to six months before the full benefits of this medication are experienced.

Side Effects

Hydroxychloroquine typically is very well tolerated. The most common side effects are nausea and diarrhea, which often improve with time. Less common side effects include rash, hair changes, and muscle weakness. Rarely, hydroxychloroquine can lead to anemia in some individuals. This can happen in individuals with a condition known as G6PD deficiency or porphyria.

In rare cases, hydroxychloroquine can cause visual changes or loss of vision. Such problems are more likely to occur in individuals taking high doses for many years, in individuals 60 years or older, those with significant kidney or liver disease, and those with underlying retinal disease. At the recommended dose, the development of visual problems due to the medication is rare. It is recommended that you have an eye exam within the first year of use, then repeat every 1 to 5 years based on current guidelines.

Additional rare reports of changes in the heart rhythm have been reported with the use of hydroxychloroquine, particularly in combination with other medications. While monitoring for this risk is not typical in the office setting, it has been indicated in hospitalized and critically ill patients to evaluate for interactions with other medications.

Tell Your Rheumatology Provider

Although there are few drug interactions with hydroxychloroquine, be sure to tell your rheumatology provider about all the medications you are taking, including over-the-counter drugs and natural remedies.

Be sure to notify your other providers when taking this drug. This drug is not known to suppress your immune system but rather to alter some functions within it. Vaccines recommended for healthcare maintenance are generally acceptable. Notify your eye doctor when you are on this medication so regular visual screening tests can be performed. If you are pregnant, considering becoming pregnant, or lactating, please discuss with your rheumatology provider that you are taking this medication. Hydroxychloroquine has been shown to be safe during pregnancy and breastfeeding.

Updated February 2024 by Timothy Kaniecki, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.

This information is provided for general education only. Individuals should consult a qualified healthcare provider for professional medical advice, diagnosis, and treatment of a medical or health condition.

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