Hydroxychloroquine (Plaquenil, Plaquenil Sulfate)


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 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?

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.

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.

What is the dosage?

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.

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.

Most common possible side effects

  • This list includes the more common side effects of hydroxychloroquine they are usually mild and short lived:
    • Vision changes
    • Nausea/vomiting
    • Diarrhoea
    • Anorexia
    • Abdominal cramps
    • Itch
    • Headache

Less common or rare possible side effects

  • Contact your doctor if you suspect one of these less common side effects
    • Thinning of the hair, 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.
    • Hydroxychloroquine may rarely cause increased skin pigmentation.
    • Hydroxychloroquine may very rarely cause temporary blurring of vision due to deposits in the front of the eye (cornea). In its early form it is usually 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 possible side effects

  • Contact your doctor if you notice any of the following:
    • Ringing in the ears
    • Bleaching of the skin and/or hair
    • Abnormal weakness of the leg muscles
    • Changes in the way your heart beats

What precautions are necessary?

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.

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.

More information is available on Vaccinations in Rhematology and COVID-19 vaccination.

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.

More detailed information is available here.

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

  • You should see your nominated doctor regularly to make sure the treatment is working and check for possible side effects.
  • You may need regular blood tests as suggested by your rheumatologist.
  • It is important to tell your rheumatologist if you have a new serious illness such as a serious infection, cancer or heart failure.
  • If you are worried about any side effects, you should contact your rheumatologist as soon as possible.
  • If you stop hydroxychloroquine for any reason, you must contact your doctor.
  • If you plan to become pregnant, you must discuss the timing with your nominated doctor/rheumatologist.

This Information Sheet has been prepared using materials obtained from various sources which have been reviewed by the Australian Rheumatology Association (ARA). It contains general information only and does not contain a complete or definitive statement of all possible uses, actions, precautions, side effects or interactions of the medicines referenced. This information is not intended as medical advice for individual conditions nor for making an individual assessment of the risks and benefits of taking a particular medicine. Decisions regarding the assessment and treatment of patients are the sole responsibility of the treating medical professional, exercising their own clinical judgment and taking into account all of the circumstances and the medical history of the individual patient. ARA has used all reasonable endeavours to ensure the information on which this Information Sheet is based is accurate and up to date. However, the ARA accepts no responsibility or liability for the accuracy, currency, reliability and/or completeness of the information contained in this Information Sheet.  To the maximum extent permitted by law, the ARA expressly disclaims any liability for any injury, loss, harm or damage arising from or in connection with use of and reliance on the information contained in this Information Sheet. This information sheet is copyright and may be reproduced in its entirety but may not be altered without prior written permission from the ARA.

Last reviewed May 2024.