Plaquenil (Hydroxychloroquine) - An Older DMARD for Rheumatoid Arthritis

11 Facts You Should Know

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Plaquenil (hydroxychloroquine) is considered an older DMARD (disease modifying anti-rheumatic drug). Plaquenil was actually first classified as an antimalarial drug, but it is also used to treat certain rheumatic and autoimmune conditions which are unrelated to malaria. Generally, Plaquenil is a treatment option as monotherapy (used alone) for mild rheumatoid arthritis or as combination therapy with other DMARDs for moderate to severe disease.

A Bit of History

The origin of antimalarials dates back to the 1630s in Peru. The bark from the "fever tree' was found to contain the antimalarial compound, quinine. In 1820, chemists purified the quinine from the bark. Fast forward to 1951, when there was anecdotal evidence of improvement in lupus and rheumatoid arthritis by WWII Allied troops who were taking a synthetic form of quinine, called quinacrine, to prevent malaria. Over time, other derivatives of quinine were released by the FDA—chloroquine in 1952 and hydroxychloroquine in 1955.  

Plaquenil is associated with potential side effects, one of which is particularly worrisome to people who are prescribed the drug. Safe use helps to minimize undesirable side effects.

1 - Although Plaquenil is an older drug, it is still available and prescribed to some people who have rheumatoid arthritis or certain other rheumatic diseases.

Plaquenil is a DMARD which has been prescribed for years to treat rheumatoid arthritis, lupus, juvenile rheumatoid arthritis, and other autoimmune diseases.

When the first biologic DMARD received FDA-approval in 1998, and as other biologics followed in subsequent years, it appeared as though Plaquenil would become less prescribed. The drug still holds its place as a treatment option for some people, particularly in conjunction with methotrexate, or people who have systemic lupus erythematosus.

Plaquenil is also an option for those who try and fail biologic drugs, cannot tolerate biologics, or fear potential side effects linked to biologic DMARDs.

2 - Plaquenil is prescribed as a disease-modifier, in other words, to decrease pain, decrease swelling, and prevent joint damage and disability.

It is not known how Plaquenil works but researchers believe that Plaquenil interferes with communication between cells within the immune system. Ultimately, it is thought to block proinflammatory pathways.

3 - The usual starting dose of Plaquenil is 200 mg twice a day or 400 mg once a day, administered orally, in people weighing 80 kg or more.

The usual dosage works for most people who take Plaquenil, but it is possible to increase or decrease the dose based on individual needs. It's important to watch for possible side effects and toxicity. For people who weigh less than 80 kg, a lower daily dose is prescribed, up to a maximum of 5 mg/kg of body weight.

4 - Plaquenil is a slow-acting drug.

People who take Plaquenil may begin to notice improvement after one or two months.

It may take up to six months before full benefits of Plaquenil are realized.

5 - Plaquenil is generally well-tolerated, but side effects are possible.

Common side effects linked to Plaquenil include nausea and diarrhea. Taking the medication with food eases nausea for most people taking the drug. Less common side effects include skin rashes, hair thinning, and weakness. A rare side effect of Plaquenil involves visual changes or possible loss of vision—the side effect that is most worrisome for patients.

6 - The aforementioned rare side effect that affects vision (hydroxychloroquine retinopathy), if caught early, may improve after discontinuation of Plaquenil.

Since the side effect of vision loss is possible but rare, it is important  for you to tell your doctor about any vision changes that you experience. Doctors generally recommend regular eye exams while on Plaquenil, so that early changes can be caught. Once abnormalities are discovered, toxicity has already occurred. While it may be reversible if caught early, hydroxychloroquine retinopathy is not always reversible.

7 - Certain people are more susceptible than others to potential vision problems with Plaquenil.

Once again, vision changes linked to Plaquenil are rare, but certain people are at higher risk for developing the problem. High risk patients would include those who:

  • have taken high doses of Plaquenil for years (i.e., 1000 g. for over 7 years)
  • are 60 years or older
  • are obese
  • have significant liver or kidney disease
  • have pre-existing retinal, macular disease, or cataracts

8 - All individuals starting Plaquenil treatment should have a baseline opthalmologic examination within the first year.

If the initial opthalmologic examination is normal and the person is considered low risk, re-testing need not occur for five years. It is recommended that high risk patients have annual eye examinations.

9 - Certain drugs may interact with Plaquenil, affecting how it works or causing it to be less effective. Tell your doctor about every medication and supplement you are taking.

Drugs which may interact with Plaquenil include:

  • antacids
  • botulinum toxins
  • digoxin
  • kaolin
  • magnesium trisilicate
  • methotrexate
  • metoprolol
  • penicillamine

10 - If you are pregnant or considering becoming pregnant, discuss Plaquenil with your doctors.

Though Plaquenil is generally regarded as safe during pregnancy, it is recommended that effective birth control be used throughout the course of Plaquenil treatment and for up to six months after treatment is stopped.

11 - Plaquenil has been associated with additional beneficial properties in people with rheumatic disease.

In people treated with Plaquenil as a disease-modifying anti-rheumatic drug, the drug was found to have other beneficial effects. Plaquenil was found to improve lipid profiles, control glucose and reduce the risk of diabetes mellitus, and lower the risk of thrombosis in certain people who are at greater risk.

Sources:

Cannon, Michael, MD. Hydroxychloroquine (Plaquenil). American College of Rheumatology. Updated March 2015.

Radis, Charles, DO. Plaquenil: From Malaria Treatment to Managing Lupus, RA. The Rheumatologist. May 15, 2015.

Screening for Hydroxychloroquine Retinopathy. Position Statement from American College of Rheumatology. August 2016.

Wallace, Daniel, MD. Antimalarial Drugs in the Treatment of Rheumatic Disease. UpToDate. January 10, 2017.

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