Hydroxychloroquine is a treatment for malaria but has been shown to be a useful treatment in RA as well. It is one of the mildest RA drugs, which means it has less likelihood of side effects but is also less powerful, so normally given in combination with other drugs.  


Hydroxychloroquine is a treatment for malaria but has been shown to have an effect on the messaging system between cells by interrupting the inflammatory response. It is this mechanism that is beneficial in both RA and juvenile idiopathic arthritis (JIA).  

Hydroxychloroquine has been available since the 1970s and is used widely for the treatment of lupus (SLE) but is also an established drug for the treatment of mild RA. It is commonly used in combination with one or two other disease modifying anti-rheumatic drugs (DMARDs), particularly methotrexate.  


  • Hydroxychloroquine was first developed as the drug ‘chloroquine’ to treat malaria  
  • Chloroquine was modified to hydroxychloroquine to significantly reduce the possible side effects that were causing eye problems  

How does it work?  

  • Hydroxychloroquine is available as a 200mg and 300mg tablet  
  • The action of hydroxychloroquine is not fully understood and it is a cumulative effect over several weeks before any benefit is seen  
  • Blood tests for hydroxychloroquine are checked before treatment starts and then as frequently as the specialist advises, usually at clinic visits. When it is prescribed alongside other DMARDs the frequency of blood tests may be more regular, depending on the recommendations for the other DMARD(s)  

Most commonly reported side effects  

As with any medication, hydroxychloroquine has a number of possible side effects, although it is important to remember that these are only potential side effects and they may not occur at all. Side effects may include:  

  • Loss of appetite, anorexia  
  • Headache  
  • Skin reactions – rash, itching, photosensitivity (increased sensitivity to sunlight)  
  • Visual changes – blurring*  
  • Abdominal pain, cramps, nausea  
  • Diarrhoea, vomiting  
  • Blood disorders  
  • Risk of episodes of low blood sugar levels in patients with diabetes  

* The Royal College of Ophthalmologists has reviewed screening for visual side effects to hydroxychloroquine and these are very rare. Vision should be checked prior to the start of treatment and corrective spectacles prescribed if required. During treatment any visual symptoms need to be checked annually. Referral to an ophthalmologist is required if any changes are detected.  

Please note: over-dosage is very dangerous, particularly in small children.  

More information on side effects can be found in the patient information leaflet for hydroxychloroquine that comes with your medicine.  

Remember to report any concerns about possible side effects to your doctor, your pharmacist or nurse.  

Hydroxychloroquine with other medicines  

There are some significant potential drug interactions between hydroxychloroquine and some other medications (particularly treatments used for other health conditions) and these risks can be minor or major. It is therefore particularly important that a full and complete medical history is given to the prescribing doctor.  

Remember to take care when using any other medications or complementary therapies (even if bought ‘over the counter’ for colds or flu and, importantly, any antacids for indigestion). Remember to check with a doctor, nurse or pharmacist that they are safe to take with hydroxychloroquine and any other medication taken.  

Hydroxychloroquine during pregnancy and breast-feeding  

For those who are already taking hydroxychloroquine and wishing to start a family, it is advisable to speak to your consultant about continuing with Hydroxychloroquine.  

Hydroxychloroquine must be stopped during the weeks or months of breastfeeding as it is transferred in breast milk.  

Hydroxychloroquine and alcohol  

As hydroxychloroquine is frequently prescribed alongside other DMARDs it is really important that any advice that relates to another DMARD must be acknowledged and used to guide you when taking Hydroxychloroquine. This is particularly the case when you are taking Hydroxychloroquine with methotrexate and sulfasalazine.  

For those over 18 years there is no reason to avoid moderate alcohol consumption whilst on hydroxychloroquine (though advice on alcohol intake will depend on the advice for any other drugs being taken as stated above). Please see our separate articles on other RA medications.  

Hydroxychloroquine and immunisation/vaccination  

Live vaccines (measles, mumps, rubella (MMR), chickenpox, oral polio (NOT injectable polio), BCG, oral typhoid and yellow fever) cannot be given to anyone already taking hydroxychloroquine. If hydroxychloroquine has not yet been started it is important to seek advice on how long a gap to leave after having a live vaccine. 

  • The annual flu vaccination and ‘pneumovax’ protection against pneumonia is permitted  
  • If possible have ‘pneumovax’ protection before starting hydroxychloroquine  

Flu vaccine is now available in two forms, an injection for adults and a nasal spray for children. The injection is not a live vaccine and therefore suitable for adults taking hydroxychloroquine and is recommended. The nasal spray is a live vaccine and not suitable for adults taking hydroxychloroquine. It is important to discuss having a flu vaccination with your GP.  

Vaccination of close family members can help to protect someone with a lowered immune system. 

 Hints and tips  

Hydroxychloroquine can make skin more sensitive to sunlight. The following tips can help with this:  

  • Remember to use sunscreen before going into the sun, as well as a t-shirt and hat  
  • Re-apply sunscreen as frequently as recommended 

Medicines in rheumatoid arthritis

We believe it is essential that people living with RA understand why certain medicines are used, when they are used and how they work to manage the condition.