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Generic name: dapsone [ DAP-sone ]
Dosage form: oral tablet (100 mg; 25 mg)
Drug class: Leprostatics

Medically reviewed by on Nov 9, 2022. Written by Cerner Multum.

What is dapsone?

Dapsone is an anti-infective medicine that fights bacteria.

Dapsone is used to treat dermatitis herpetiformis (a skin condition) and leprosy.

Dapsone may also be used for purposes not listed in this medication guide.

Dapsone side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Dapsone may cause serious side effects. Call your doctor at once if you have:

  • worsening or no improvement in your symptoms;

  • jaundice (yellowing of the skin or eyes);

  • numbness or tingling in your hands or feet;

  • unusual thoughts or behavior;

  • new or worsening cough, fever, trouble breathing;

  • swelling, rapid weight gain, little or no urinating;

  • signs of abnormal blood cell counts--sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing, pale skin, easy bruising, purple or red pinpoint spots under your skin;

  • pancreas problems--severe pain in your upper stomach spreading to your back, nausea and vomiting, fast heart rate;

  • an autoimmune disorder--joint pain or swelling with fever, headaches, confusion, chest pain, shortness of breath, and butterfly-shaped skin rash on your cheeks and nose that worsens in sunlight; or

  • severe skin reaction--fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common side effects of dapsone may include:

  • stomach pain, nausea, vomiting;

  • headache;

  • dizziness or spinning sensation;

  • blurred vision, ringing in your ears; or

  • sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use dapsone if you are allergic to it.

To make sure dapsone is safe for you, tell your doctor if you have:

  • a genetic enzyme deficiency called glucose-6-phosphate dehydrogenase (G6PD) deficiency;

  • methemoglobin reductase deficiency (hemoglobin M);

  • liver disease;

  • heart disease; or

  • lung disease.

FDA pregnancy category C. It is not known whether dapsone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Dapsone can pass into breast milk and may harm a nursing baby. You should not breast-feed while using dapsone.

How should I take dapsone?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Dapsone may be only part of a complete program of treatment that may also include a special diet. Follow the diet plan created for you by your doctor or nutrition counselor. Get familiar with the list of foods you must avoid to help control your condition.

Your doctor will need to check your progress while you are using dapsone.

Store at room temperature away from moisture, heat, and light.

Dapsone dosing information

Usual Adult Dose for Leprosy -- Lepromatous:

50 to 100 mg orally once a day for 2-5 years.

Usual Adult Dose for Leprosy -- Tuberculoid:

100 mg orally once a day for 6 months. Rifampin is additionally recommended to reduce the incidence of dapsone resistance. If the disease relapses, this regimen should be repeated.

Usual Adult Dose for Dermatitis Herpetiformis:

50 mg orally once a day continued on a life-long basis. Dosage may be advanced to 300 mg/day. Dosage reduction to a minimum maintenance level as soon as possible is recommended.

Usual Adult Dose for Pneumocystis Pneumonia:

100 mg orally once a day for 14 to 21 days. Used in combination with trimethoprim.

Usual Adult Dose for Pneumocystis Pneumonia Prophylaxis:

100 mg orally twice a week. Therapy should be continued on a life-long basis. The addition of pyrimethamine appears to significantly increase the activity of dapsone for PCP prophylaxis.

Usual Adult Dose for Toxoplasmosis -- Prophylaxis:

100 mg orally twice a week continued on a life-long basis.

Usual Pediatric Dose for Leprosy:

1 to 2 mg/kg (up to 100 mg) orally once a day.

Usual Pediatric Dose for Pneumocystis Pneumonia Prophylaxis:

> 1 month:
2 mg/kg/day (up to 100 mg) orally once a day.

Alternate dosing:
> 1 month:
4 mg/kg orally once weekly. Maximum dose = 200 mg.

Usual Pediatric Dose for Toxoplasmosis -- Prophylaxis:

> 1 month:

2 mg/kg/day (or 15 mg/m2) orally once a day. Maximum dose = 25 mg. Dapsone should be administered as part of combination therapy for prophylaxis of toxoplasmosis.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may vomiting, feeling restless or excited, and a pale or blue-colored appearance.

What should I avoid while taking dapsone?

Avoid exposure to sunlight or tanning beds. Dapsone can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What other drugs will affect dapsone?

Other drugs may interact with dapsone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.