6 mins read

Overview: Dapsone is used to treat leprosy and dermatitis herpetiformis (a rash due to gluten sensitivity). Dapsone is an antibiotic that stops the growth of certain bacteria and also helps block immune cells from causing damage. Common side effects include hemolysis (breakdown of red blood cells), nausea or vomiting, stomach pain, dizziness, blurred vision, and ringing in the ears. Serious side effects may include blood disorders, skin reactions, liver inflammation, and nerve problems.

Uses

What is dapsone used for?

Dapsone is commonly used for the following conditions.

  • Dermatitis herpetiformis, a bumpy, itchy rash caused by gluten sensitivity
  • Leprosy, an infection that causes severe skin and nerve damage in the limbs and other areas on your body

Dapsone may also be used for other conditions as determined by your healthcare provider.

How does dapsone work (mechanism of action)?

Dapsone is an antibiotic that can stop the growth of certain bacteria, such as those that cause leprosy. It works by stopping the bacteria from making a chemical they need to grow and multiply. 

How dapsone works to treat dermatitis herpetiformis is not fully understood, but it is thought to block certain immune cells from entering and causing damage at the site of rash.

How is dapsone supplied (dosage forms)?

Brands and other names

  • Avlosulfon

Dosage forms and strengths

  • 25 mg oral tablets
  • 100 mg oral tablets

Dapsone is also available in a topical form. See Dapsone topical for more information.

How should I store dapsone?

Dapsone should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect from light.

Side Effects

What are the most common side effects of dapsone?

The most common side effects of dapsone are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Hemolysis, which is a breakdown of red blood cells (see below)
  • Nausea or vomiting
  • Stomach pain
  • Dizziness
  • Blurred vision
  • Ringing in the ears

There may be other side effects of dapsone that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of dapsone?

While less common, the most serious side effects of dapsone are described below, along with what to do if they happen.

Severe Allergic Reactions. Dapsone may cause allergic reactions, which can be serious. Stop taking dapsone and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Hemolysis and Other Blood Disorders. Dapsone can cause blood disorders, such as agranulocytosis, aplastic anemia, hemolytic anemia, low platelet levels (thrombocytopenia), and low white blood cell levels (leukopenia). Stop taking dapsone and get help right away if you have any of the following symptoms of blood disorders.

  • Fever
  • Shortness of breath
  • Pale or yellowish skin
  • Easy bruising or bleeding
  • Frequent infection
  • Unusual weakness or tiredness
  • Dizziness, lightheadedness, or feeling like you are about to pass out
  • Headache
  • Fast or abnormal heartbeat

Serious Skin Reactions. Dapsone can cause serious skin reactions, including exfoliative dermatitis and toxic epidermal necrolysis (TEN). These skin reactions can be serious or lead to death. If you develop a rash, stop dapsone and call your healthcare provider right away. Get emergency help if you have any of the following symptoms.

  • Painful red or purple skin that looks burned and peels off
  • Flat red rash or blisters on your skin, mouth, nose, and genitals
  • Red, painful, watery eyes

Liver Inflammation (Hepatitis). Dapsone can cause liver inflammation, also known as hepatitis. Keep all appointments to have your blood work checked. Call your healthcare right away if you have any of the following symptoms of liver inflammation.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Nerve Problems. Nerves are the fibers that carry sensations from your body to the brain. Damage to these nerves, called peripheral neuropathy, can happen in people who are taking dapsone. Stop taking dapsone and contact your healthcare provider right away if you develop pain, burning, tingling, numbness, or weakness in your arms, hands, legs, or feet.

Warnings & Precautions

Who should not use dapsone?

Allergies to Ingredients. People who are allergic to any of the following should not take dapsone.

  • Dapsone
  • Avlosulfon
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific dapsone products they stock.

What should I know about dapsone before using it?

Do not take dapsone unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share dapsone with other people, even if they have the same condition as you. It may harm them.

Keep dapsone out of the reach of children.

Attend all appointments for bloodwork before and during your treatment with dapsone.

If you are taking dapsone to treat leprosy, your healthcare provider may prescribe other medicines to take with dapsone. This is to minimize the risk of leprosy becoming resistant to treatment. Take your medicines as instructed for the full duration.

Certain reactions can happen in people being treated for leprosy. These are known as reactional states. Symptoms may include swelling or inflammation of the skin and nerves, redness, fever, tenderness, and weakness. These reactions are not caused by dapsone. Tell your healthcare provider if you are taking dapsone for leprosy and notice any of these symptoms. Severe reactions may require treatment or hospitalization.

What should I tell my healthcare provider before using dapsone?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if dapsone is right for you.

In particular, make sure that you discuss any of the following.

Blood Disorders. Tell your healthcare provider if you have any blood disorders, including a genetic condition called glucose-6-phosphate dehydrogenase (G6PD) deficiency, anemia, or methemoglobin reductase deficiency. These conditions may increase your risk of developing certain side effects with dapsone.

Other Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Liver problems
  • Heart problems
  • An infection

Other Medicines and Supplements. Dapsone may interact with other medicines and supplements. Before taking dapsone, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how dapsone could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take dapsone while you are pregnant or trying to get pregnant.

Breastfeeding. Dapsone passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop dapsone.

Interactions

Does dapsone interact with foods or drinks?

There are no known interactions between dapsone and foods or drinks.

It is unknown if drinking alcohol will affect dapsone.

Does dapsone interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking dapsone.

  • Rifampin (Rifadin), which is a medicine commonly used to treat an infection called tuberculosis
  • Pyrimethamine, which is a medicine used to treat certain parasitic infections
  • Trimethoprim, which is an antibiotic used to treat certain infections
  • Methotrexate (Trexall and others), which is a medicine commonly used for rheumatoid arthritis or certain types of cancer
  • A folic acid antagonist or antifolate, which is a medicine commonly used to treat certain cancers or infections

This may not be a complete list of medicines that can interact with dapsone. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much dapsone?

If you or someone else has used too much dapsone, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of dapsone?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.