Dapsone: Uses, Function, Precautions and Side Effects

It is a tablet that is taken for several varied dermatological conditions. The dose varies between 50 and 200 mg a day, taken at once.

The duration of treatment will depend on progress and can vary from months to several years.

Regular monitoring by your doctor is essential when starting to use this medication due to possible serious side effects. Dapsone can be taken with or without food, but it should be taken each day simultaneously.

How does dapsone work?

Dapsone works on inflammatory cells, particularly neutrophils (a type of white blood cell), and reduces skin inflammation.

This medicine can be available under many brand names and in different forms. Any specific brand of this drug may not be available on all documents or approved for all conditions discussed here.

Also, some forms of this drug cannot be used for all conditions discussed here.

For what do you use it?

Most commonly, dapsone is prescribed by dermatologists to treat dermatitis herpetiformis.


It can also be prescribed for:

  • IgA linear disease (bullous dermatosis of childhood).
  • Leprosy.
  • Systemic lupus erythematosus.
  • Autoimmune bulimic diseases.
  • Pyoderma gangrenous.
  • Sweet’s syndrome (acute febrile neutrophilic dermatosis).
  • Behcet’s syndrome.

Precautions when taking dapsone

  • Do not take dapsone if you have had allergic reactions to sulfur-based medications, such as sulfapyridine, sulfonamide, or sulfones.
  • Tell your doctor if you have any pre-existing lung, heart, or blood disorders.
  • Do not give your medicine to anyone else.
  • Dapsone is not safe during pregnancy. However, there have been several cases of dapsone use in pregnant women without adverse effects.
  • Don’t breastfeed when taking dapsone.

Do not take the following medications with dapsone unless this has explicitly been discussed with your doctor:

  • Trimethoprim.
  • Probenecid.
  • Pirimetamina.
  • Rifampicin.
  • Sulfonamides.
  • Hydroxychloroquine.

What monitoring is required?

Several initial blood tests will be done to ensure there are no underlying problems.

These include a complete blood count to check liver and kidney function and the enzyme glucose-6-phosphate dehydrogenase levels.

If these tests are all satisfactory, regular blood tests (initially weekly, then biweekly, and tapering to every 3 to 4 months when stable) will be needed to make sure you are doing well on the drug.

Side effects

The most common side effects are stomach pain, nausea, and loss of appetite.

Hemolytic anemia: Dapsone affects red blood cells and can cause them to break down. In most cases, this is only noticeable in blood tests, but occasionally it can lead to increased tiredness and fatigue.

Methemoglobinemia: Since dapsone affects the red blood cells in our body, it can reduce their ability to carry oxygen.

It can make you feel out of breath (especially if you already have lung or heart problems), and the reduced oxygen can make your tongue look blue.

Tell your doctor if you are experiencing any of these side effects.

There are two severe side effects to be aware of:

Agranulocytosis: This is caused by a sudden drop in the cells that fight infection and usually occurs 3 to 12 weeks after starting treatment.

This could lead to severe infections. Tell your doctor if you develop a fever or flu-like symptoms while taking dapsone. Stopping the drug can reverse it and should be done as soon as possible.

Hypersensitivity syndrome: It is a combination of signs and symptoms that includes fever, skin rash, and liver abnormalities. It occurs 3 to 6 weeks after starting treatment.

Notify your doctor immediately if you develop these signs. Some deaths have been reported from agranulocytosis and hypersensitivity syndrome.

Nerve damage: The most common form of nerve damage is weakness in the muscles of the legs. The sensation can sometimes be affected. In rare cases, changes in eyes and mental status have been reported.

Tell your doctor if you have any unusual signs or symptoms while taking dapsone. Knowing the possible side effects is vital to understanding what reactions to expect and when to seek medical attention.

Read the product information sheet with dapsone and discuss any questions with your doctor.