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Dapsone tablets

Dapsone will be prescribed for you by a specialist doctor.

Take the tablets every day for as long as your doctor tells you to. Your course of treatment may last several months or years.

If you get a rash, a high temperature, or develop any unexplained bruises or bleeding, please speak with your doctor straightaway.

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About dapsone

Type of medicine

An antibacterial medicine

Used for

Treatment of leprosy; treatment of dermatitis herpetiformis; prevention of pneumonia

Available as


Dapsone is an antibacterial medicine. It is prescribed for the treatment of two completely different conditions - a disease called leprosy, and a skin condition called dermatitis herpetiformis. It is also prescribed for people with a weakened immune system to protect them from pneumonia caused by an infection with germs (bacteria) called Pneumocystis jirovecii.

Leprosy is an infectious disease which is rare in the UK. Dapsone works by stopping the growth of the bacteria that are causing the infection. It is prescribed alongside one or more other medicines, as part of multidrug therapy (MDT).

Dermatitis herpetiformis is a skin condition, the main symptom of which is a very itchy rash. It is caused by intolerance to a food ingredient called gluten, which is a natural substance found in foods such as wheat, rye and barley. It is often linked to a condition called coeliac disease, which is also caused by gluten intolerance. Dermatitis herpetiformis can be effectively treated with dapsone and a gluten-free diet.

Dapsone is also prescribed to protect people who have a weakened immune system from pneumonia. Pneumonia, caused by bacteria called Pneumocystis jirovecii, is a serious lung infection which can affect people with a weakened immune system, such as people with AIDS.

Before taking dapsone

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking dapsone it is important that your doctor knows:

  • If you are pregnant, trying for a baby or breastfeeding. This is because you will need to take a supplement of folic acid if you are expecting a baby.

  • If you have a heart condition, or any problems with your lungs.

  • If you have a lack of iron in your blood (anaemia). This will need treating before you take dapsone.

  • If you know you have glucose 6-phosphate dehydrogenase deficiency. This is a genetic disorder where there is a lack of an enzyme often known as G6PD. People with this disorder have problems after eating foods such as fava beans.

  • If you have a rare inherited blood disorder called porphyria.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine. It is particularly important that you let your doctor know if you have had an allergic reaction to a sulfonamide medicine used to treat an infection.

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How to take dapsone

  • Before you start taking the tablets, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about dapsone and will provide you with a full list of the side-effects which you could experience from taking it.

  • Your doctor will tell you what dose is right for you - please take dapsone exactly as your doctor tells you to. It is usual to be prescribed one dose to take every day. There are two strengths of tablet - 50 mg and 100 mg. Each time you collect a new supply, check to make sure you get the same strength tablets as before, and ask your pharmacist for advice if you have any questions. The following doses (for adults) are intended as a guide only:

    • For leprosy: 50-100 mg daily.

    • For dermatitis herpetiformis: 25-300 mg daily.

    • For prevention of pneumonia: 100 mg daily.

  • You can take dapsone at whatever time of day you find easiest to remember, but try to take your doses at the same time of day each day, as this will help you to remember to take your doses regularly. Swallow the tablet with a drink of water. You can take the tablet either before or after meals.

  • If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, leave out the forgotten dose from the previous day and take the dose that is due as normal. Do not take two doses at the same time to make up for a missed dose.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor will want you to have some blood tests during this treatment.

  • Take the tablets regularly every day - do not stop taking dapsone unless your doctor tells you to do so. Your treatment may last for several months or years.

  • If you are taking dapsone for dermatitis herpetiformis, you will also have been given some advice about which foods to avoid as part of a gluten-free diet. It is important that you follow this dietary advice carefully.

  • Dapsone tablets can stop the oral typhoid vaccine from working. If you are due to have any vaccinations, please make sure that the person treating you knows that you are taking this medicine.

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Can dapsone cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones which can occur with dapsone. You will find a full list in the manufacturer's information leaflet supplied with your medicine. Speak with your doctor or pharmacist if any of the following continue or become troublesome.

Dapsone side-effects

What can I do if I experience this?


Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know

Feeling sick (nausea) or being sick (vomiting)

Stick to simple foods (avoid rich or spicy meals)

Increased sensitivity to sunlight

Use a sun cream that has a sun protection factor (SPF) of at least 15. Do not use sunbeds

Difficulties sleeping, skin tinglings,

feeling weak, feeling your heart is beating quickly, loss of appetite, disturbed thoughts

If any of these become troublesome, please speak with your doctor

Changes to the result of a blood test which checks how well your liver is working

Your doctor will monitor for this

Important: if you develop a skin rash or any unexplained bruising or bleeding, a high temperature (fever), a sore throat, or mouth ulcers, you should speak with a doctor straightaway. These are rare but serious side-effects that you must tell your doctor about as soon as possible.

If you experience any other symptoms which you think may be due to the tablets, please speak with your doctor or pharmacist for further advice.

How to store dapsone

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

If you buy any medicines check with a pharmacist that they are safe to take with your other medicines.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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