About dapsone

Leprosy is an infectious disease which is rare in the UK. Dapsone works by stopping the growth of the bacteria that cause the infection. You will have been prescribed dapsone alongside one or more other medicines to treat leprosy.

Dermatitis herpetiformis is a skin condition which is associated with coeliac disease. It is caused by intolerance to a food ingredient called gluten. It can be effectively treated with medication plus a gluten-free diet. Dapsone is the usual medicine used to treat it.

Dapsone can also be used for some other conditions not covered by this medicine leaflet. If you have been prescribed dapsone for any other reason (such as to protect you from pneumonia if you have a weakened immune system), you should ask your doctor if you have any questions about your treatment.

Before taking dapsone

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

• If you are pregnant, trying for a baby or breast-feeding. This is because you will need to take supplements of folic acid if you are expecting a baby.
• If you have any problems with your heart or lungs.
• If you have anaemia (a lack of iron in your blood). This will need treating before you take dapsone.
• If you know you have glucose 6-phosphate dehydrogenase (G6PD) deficiency. This is a genetic disorder which causes problems after eating foods such as fava beans.
• If you have porphyria (this is a rare inherited blood disorder).
• If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine. It is particularly important that your doctor knows if you have ever had an allergic reaction to a sulphonamide medicine used to treat an infection.

How to take dapsone

• Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about dapsone, and a full list of side-effects which you may experience from taking it.
• Take dapsone exactly as your doctor has told you - your dose will also be on the label of the pack to remind you. Take the tablets once daily with a drink of water. There are two strengths of tablet (50 mg and 100 mg), so each time you collect a new prescription, check to make sure you get the same strength as before. If you are unsure, ask your pharmacist to check for you.
• You may take dapsone at whatever time of day you find easiest to remember, but try to take your doses at the same time each day. This will help you to avoid missing any doses. You can take the tablets before, during or after your meals.
• If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, skip the missed dose. Do not take two doses together to make up for a forgotten 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 to do some blood tests during this treatment.
• Take this medicine regularly every day - do not stop taking it unless your doctor tells you to do so. Your treatment may last 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 may stop the oral typhoid vaccine from working. If you are having any vaccinations, make sure the person treating you knows that you are taking this medicine.
• If you buy any medicines, check with a pharmacist that they are safe to take with dapsone.

Can dapsone cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Important: your doctor will have discussed with you the possibility of unwanted side-effects that you must let your doctor know about. Contact your doctor straightaway if you experience any of the following:

• a skin rash,
• a high temperature,
• a sore throat, or mouth ulcers,
• any unexplained bruising or bleeding.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

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