What is hydroxychloroquine?

Hydroxychloroquine (brand name Plaquenil, Plaquenil Sulfate) is a medicine used to treat rheumatoid arthritis and other inflammatory conditions such as systemic lupus erythematosus (SLE/Lupus).

Hydroxychloroquine is also an antimalarial medicine used to prevent and treat malaria and other parasitic infections. It is not used routinely now for this purpose because of resistance by the parasites.

It is not clear how hydroxychloroquine works in inflammatory conditions; however it is thought to have an action on the immune system. In rheumatoid arthritis this action helps to reduce inflammation and thus reduce pain and swelling. It also limits damage to the joints and helps to prevent disability in the long term.

Because hydroxychloroquine acts to reduce the damage to the joints, rather than just relieve the pain, it belongs to the group of medicines called disease modifying antirheumatic drugs (DMARDs).

What benefit can you expect from your treatment?

About 60% of people treated with hydroxychloroquine experience improvement in their condition.

Hydroxychloroquine does not work straight away. It may take 8 to 12 weeks for symptoms to start to improve. The full effect of treatment may take up to 26 weeks.

Other medicines may be given to improve your symptoms while waiting for hydroxychloroquine to work.

How is hydroxychloroquine taken?

Hydroxychloroquine is taken by mouth in tablet form. The usual dose is one tablet (200mg) once or twice a day. Tablets can be taken altogether, once a day.

The dose may be reduced to a maintenance dose after a few months once a response is achieved. Occasionally it may be taken every second day.

It is best taken with food as it has a slightly bitter taste.

Hydroxychloroquine is not a pain killer and it should be taken continuously to be effective. Other medicines may be required to treat the pain.

Hydroxychloroquine may be used with other arthritis medicines including:

• Other DMARDs such as methotrexate.
• Steroid medicines such as prednisolone or cortisone injections into the joint.
• Anti-inflammatory medicines (NSAIDs) such as naproxen (Naprosyn) and ibuprofen (Brufen, Nurofen).
• Simple pain medicines such as paracetamol.

There are separate information sheets for the medicines mentioned above.

How long is treatment continued?

Treatment with hydroxychloroquine may be continued indefinitely as long as it is effective and no serious side effects occur.

If you stop hydroxychloroquine treatment for more than a few weeks there is a risk that your condition may worsen. Continue with your treatment unless advised by your doctor or unless side effects develop.

Are there any side effects?

You might experience side effects with your treatment. Tell your doctor if you are concerned about possible side effects. A reduction in dose may minimise side effects so that you can continue to take this treatment. Your doctor will advise on any dose changes that are necessary.

Most common possible side effects

About 10% of patients experience stomach and bowel side effects such as nausea (feeling sick), loss of appetite or diarrhoea. As the tablets are slightly bitter, these problems can often be reduced by taking the tablets with food or milk, or they may just improve with time.

Less common or rare possible side effects

• Less common side effects include skin rashes and increased sensitivity to the sun. It is a good idea to wear sunscreen and a hat when in the sun. The medication may rarely worsen psoriasis rash.
• Very rarely hydroxychloroquine may cause temporary blurring of vision due to deposits in the front of the eye (cornea). This is fully reversible when the medicine is stopped. You should report to your doctor any visual disturbances, (blurred vision, mist or fog before the eyes or light sensitivity).
• More serious eye problems involving the retina (back of the eye) are extremely rare. These occur mainly in people taking a high dose for longer than 5 years, or in those who have liver or kidney problems. Your doctor will advise you about what eye testing is required.
• Very rare effects include thinning of the hair, ringing in the ears, bleaching of the skin and/or hair, and weakness of the leg muscles.

What precautions are necessary?

Eye testing

• When you start treatment with hydroxychloroquine your doctor will discuss your vision and may ask you to have an eye test. This eye test may be repeated during your treatment to monitor effects on your eyesight.

Use with other medicines

• Hydroxychloroquine can interact with other medicines. You should tell your doctor (including your general practitioner, rheumatologist and others) about all medicines you are taking or plan to take. This includes over the counter or herbal/naturopathic medicines. You should also mention your treatment when you see other health professionals.
• Most vaccines can be given safely. Talk with your rheumatologist before receiving any vaccines.

Use with alcohol

• There is no particular reason for you to avoid alcohol while taking hydroxychloroquine. However drinking more than 4 standard drinks on one occasion, even if infrequently, is strongly discouraged.

Use in pregnancy and breastfeeding

• If you intend becoming pregnant, or if you conceive while taking hydroxychloroquine, or if you are breastfeeding, you should discuss this with your doctor.
• Hydroxychloroquine can be used in pregnancy if the mother’s condition is serious however you should ask your doctor about the benefits and risks of taking hydroxychloroquine while you are pregnant.

How to store hydroxychloroquine

• Store hydroxychloroquine in a cool, dry place, away from direct heat and light (e.g. not in the bathroom).
• Keep all medicines out of reach of children.

Important things to remember

• While taking hydroxychloroquine you should see your rheumatologist regularly to make sure the treatment is working and to minimise any possible side effects.
• If you are concerned about any side effects you should contact your rheumatologist as soon as possible.
• While taking hydroxychloroquine you should have your eyes tested regularly to identify any possible side effects.

This information has been produced by the Australian Rheumatology Association (ARA) to help you understand the medicine that has been prescribed for you. Please read it carefully and discuss it with your doctor. The information in this sheet has been obtained from various sources and has been reviewed by the ARA. It is intended as an educational aid and does not cover all possible uses, actions, precautions, side effects, or interactions of the medicines mentioned. This information is not intended as medical advice for individual problems nor for making an individual assessment of the risks and benefits of taking a particular medicine. It can be reproduced in its entirety but cannot be altered without permission from the ARA. The NHMRC publication: How to present the evidence for consumers: preparation of consumer publications (2000) was used as a guide in developing this publication.

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