Hydroxychloroquine is a type of medicine called a disease-modifying anti-rheumatic drug (DMARD). It works by blocking the effects of the chemicals released when your immune system attacks your body.
Hydroxychloroquine reduces swelling (inflammation), pain and stiffness of joints, and can improve or clear up some rashes.
Hydroxychloroquine is only available on prescription. It comes as tablets.
Who can take hydroxychloroquine
Most adults and children can take hydroxychloroquine.
Hydroxychloroquine is not suitable for some people. To make sure it's safe for you, tell your doctor before taking it if you:
- have ever had an allergic reaction to hydroxychloroquine or any similar medicines, such as quinolones or quinine
- have an eye problem that affects your retina or the inside of your eye (maculopathy) or any other eye problem
- are pregnant, trying to get pregnant or breastfeeding
- have liver, kidney, heart or blood problems
- have psoriasis
- have a genetic condition called glucose-6-dehydrogenase deficiency
- have a rare inherited condition called porphyria
Dosage and strength
The tablets contain 200mg or 300mg of hydroxychloroquine.
The usual dose for adults is 200mg to 400mg each day.
If your child is prescribed hydroxychloroquine, their doctor will work out their dose based on their height and weight.
Swallow the tablets whole. Take them with or just after food, or with a glass of milk.
If you take antacids for indigestion, leave a gap of at least 4 hours between taking them and hydroxychloroquine.
How long to take it for
How long you take hydroxychloroquine for depends on why you're taking it.
For some conditions, if hydroxychloroquine works for you then you may need to take it for several years, or even for the rest of your life, to control your symptoms.
If you're taking hydroxychloroquine for a skin condition, you may only need to take it 2 or 3 times a week, or only during the summer.
It may take several weeks before you notice the benefit of taking hydroxychloroquine.
Keep taking hydroxychloroquine until your doctor tells you to stop. Do not stop taking it just because you feel better. If you stop, your symptoms may get worse again.
If you forget a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time to make up for a missed dose.
If you take too much
Taking too much hydroxychloroquine can cause problems.
- you've taken more than your prescribed dose of hydroxychloroquine, even if you feel well
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the medicine packet or leaflet inside it, plus any remaining medicine, with you.
Common side effects
These common side effects of hydroxychloroquine happen in more than 1 in 100 people. There are things you can do to help cope with them:
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Some people have a serious side effect from hydroxychloroquine.
Tell your doctor or contact 111 straight away if you get:
- any eye problems, including changes in the colour of your eye or problems with your eyesight such as blurred vision, sensitivity to light or changes to the way you see colour
- muscle weakness, cramps, stiffness or spasms, or changes in how your skin feels such as tingling
- frequent infections with a high temperature, sore throat or mouth ulcers
- bruising that happens more easily than usual
- signs of low blood sugar (hypoglycaemia), such as sweating or feeling dizzy, shaky or anxious
- skin reactions such as a large area of scaly skin, pus-filled spots together with a high temperature, or your skin becoming more red than usual and being more sensitive to the sun (this may be less obvious on brown or black skin)
- irrational thoughts, feeling anxious, seeing things that are not real (hallucinations), feeling confused or feeling depressed, including thoughts of self harm even if you have never had similar problems before
Serious allergic reaction
In rare cases, hydroxychloroquine may cause a serious allergic reaction (anaphylaxis).
If you take hydroxychloroquine for a long time, your doctor will monitor you to check for any long-term side effects.
For example you may have regular full blood counts (tests to check the types and numbers of cells in your blood) and eye examinations.
Your doctor will occasionally check your muscles and tendons to make sure they are working properly.
Other side effects
These are not all the side effects of hydroxychloroquine. For a full list see the leaflet inside your medicine packet.
Hydroxychloroquine and pregnancy
You can safely take hydroxychloroquine during pregnancy.
If they're not well treated, inflammatory conditions like arthritis and lupus can affect your baby, causing premature birth and growth problems.
It's recommended that you keep taking hydroxychloroquine during pregnancy to keep you and your baby well.
If your doctor or health visitor says your baby is healthy, it's OK to take hydroxychloroquine while you're breastfeeding.
Hydroxychloroquine passes into breast milk in very small amounts. It has not been known to cause any side effects in breastfed babies.
If your baby is not feeding as well as usual, seems irritable, is not sleeping, or has an upset stomach, or if you have any other concerns about your baby, talk to your doctor, pharmacist, health visitor or midwife.
Hydroxychloroquine and fertility
There's no evidence to suggest that taking hydroxychloroquine reduces fertility in either men or women.
Speak to a pharmacist or your doctor if you're trying to get pregnant.
Cautions with other medicines
Hydroxychloroquine can affect the way some medicines work. Other medicines can also affect the way hydroxychloroquine works or increase the chance of you getting side effects.
If you take antacids, leave a gap of at least 4 hours between taking them and hydroxychloroquine.
Tell your doctor or pharmacist if you're taking any other medicines, including:
- azithromycin, erythromycin or clarithromycin, antibiotics
- amiodarone or digoxin, medicines for heart problems
- medicines for epilepsy
- medicines for diabetes, such as insulin or metformin
- cimetidine, a medicine for stomach ulcers
There's not enough information to say that herbal remedies and supplements are safe to take with hydroxychloroquine. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
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