Hydroxychloroquine

Hydroxychloroquine (Plaquenil) is a disease-modifying anti-rheumatic drug (DMARD) indicated (approved for use) for the treatment of RA.

 

How does hydroxychloroquine work?

Hydroxychloroquine is an antimalarial drug. It is derived from quinine and cinchonine, which were originally taken from the bark of the cinchona tree found in Peru. Antimalarials modulate or change the way your immune system works. The exact mechanism of action for hydroxychloroquine and another antimalarial drug chloroquine in RA is not known, but we think that these drugs decrease production of a number of different chemicals that are important to the immune response.1

 

How is hydroxychloroquine taken?

For the treatment of RA, hydroxychloroquine is typically taken orally at a daily dose of 200-400 mg, although it can be taken at a higher dose. It can be taken in a single or divided dose (to control gastrointestinal [GI] side effects). It can also be taken with a glass of milk or meal to minimize nausea.1-3

 

How long does it take for hydroxychloroquine to take full effect?

With hydroxychloroquine, your symptoms may begin to improve in 1 to 2 months. However, it may take up to 6 months to a year before the drug achieves full effect. A loading dose of 1,200 mg daily, given for 6 weeks may decrease the time to clinical response.1,3

 

What should I do if I miss a dose of hydroxychloroquine?

If you miss a dose of hydroxychloroquine, take the missed dose as soon as you remember it. However, if it is close to the time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.2

 

How should I store hydroxychloroquine?

You should store hydroxychloroquine in the original container that it came in. Make sure that it is tightly sealed and kept out of reach of children. Keep the container at room temperature and away from moisture (not in your bathroom). Make sure that you discard any hydroxychloroquine that is outdated. Your pharmacist can tell you how to safely dispose of outdated or unused medication.2

 

Are there people who should not take hydroxychloroquine?

Hydroxychloroquine should not be taken if you experience vision symptoms, including reading or seeing difficulties, sensitivity to light, blurred distance vision, or light flashes or streaks, or if you are allergic to the drug or any of its components.4

 

What is the evidence that hydroxychloroquine works in RA?

The effectiveness of hydroxychloroquine in RA was demonstrated in two randomized, controlled trials, which included 240 patients. Hydroxychloroquine reduces RA symptoms, including pain, swelling, and tenderness, and improves physical functioning in most patients (up to 80%). Other results have shown that hydroxychloroquine can result in a decrease in the frequency of RA flares.1

Results from a recent study evaluating hydroxychloroquine given in combination with methotrexate and sulfasalazine (triple therapy) in patients who failed to respond adequately to monotherapy with methotrexate showed that this combination resulted in significant clinical improvement and slowing of radiographic progression comparable to etanercept (Enbrel) plus methotrexate.5

 

What are the side effects of hydroxychloroquine?

Antimalarials are generally well tolerated, with GI side effects occurring in about 10% of patients. Serious adverse effects, such as toxicity affecting the eyes, are rare, occurring in less than 2% of patients.1

The most common side effects with hydroxychloroquine include2:

  • Headache
  • Loss of appetite
  • Nausea
  • Diarrhea
  • Stomach pain
  • Vomiting
  • Skin rash
  • Dizziness

 

Contact your doctor immediately if you experience symptoms affecting your vision, including reading or seeing difficulties, sensitivity to light, blurred distance vision, or light flashes or streaks, or symptoms affecting your hearing, including ringing in the ears or difficulty hearing. Other potentially serious symptoms you should report to your doctor immediately include muscle weakness, bleeding or bruising, loss of hair or bleaching of hair, changes in mood, irregular heartbeat, drowsiness, and convulsions.2

 

Warnings and precautions with hydroxychloroquine

Before starting long-term treatment with hydroxychloroquine, a patient should be given a careful eye exam. Eye exams should be conducted annually during treatment with hydroxychloroquine.4

Rare cases of suicidal behavior have been reported in patients receiving hydroxychloroquine.4

In patients with psoriasis, treatment with hydroxychloroquine may result in a severe attack of psoriasis. When hydroxychloroquine is given to patients with porphyria (a rare blood disorder), it may result in a worsening of that condition.4

Use of hydroxychloroquine should be avoided in women who are pregnant (except where it is being used to suppress malaria, where the benefits outweigh the risks).4

Hydroxychloroquine should be used with caution in patients with liver disease, patients who are alcoholic, or when given with other drugs that are known to have liver toxicity.4

 

Is a generic of hydroxychloroquine available?

Yes.

Written by: Jonathan Simmons | Last reviewed: September 2013.
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