Dapsone
Description
Oral dapsone is sometimes used for rheumatologic skin diseases. It is most commonly used to treat some forms of cutaneous lupus erythematosus (including bullous lupus), vasculitis, and conditions due to increased neutrophils (neutrophilic dermatoses). Dapsone is a sulfone that decreases inflammation in the skin, particularly when neutrophils (a type of white blood cell) cause the inflammation.
Fast Facts
- Oral dapsone is used to treat cutaneous LE and vasculitis.
- A baseline G6PD enzyme test is obtained to make sure the dapsone can be properly metabolized.
- Complete blood count and liver function tests should be carefully monitored to allow adjustment of dose of medication if abnormalities develop.
Uses
Dapsone is used to treat cutaneous lupus erythematosus (LE), bullous LE, some forms of vasculitis, neutrophilic dermatoses and other autoimmune skin diseases.
How it works
Dapsone inhibits neutrophil movement and ability to initiate inflammation.
Dosing
The dose of this medicine differs for different patients and different conditions. Follow your doctor’s orders or the directions on the label. Doses range from 25 to over 200 mg/day and are normally started at lower doses and titrated up as needed and tolerated. Safety in pregnancy is not known. Do not take dapsone without first talking to your doctor if you are pregnant or could become pregnant during treatment. Dapsone passes into breast milk and may affect a nursing baby. Do not take dapsone without first talking to your doctor if you are nursing a baby. Care should be taken if you are anemic, and you should alert your doctor if you have significant lung or heart disease.
Time to effect
Once the effective dapsone dose is reached, it is effective within days. However, it may take time to reach the effective dose as the medication is started at a low dose and increased slowly over time to avoid side effects.
Side effects
It is normal to have a small decrease in your red blood cells (i.e. develop anemia) with treatment. Minor, infrequent side effects include nausea, vomiting, loss of appetite, ringing in the ears, or headache. Notify your doctor if you have persistent dizziness, blurred vision, blue discoloration of lips and fingertips, unusually fast heartbeat, shortness of breath/unusually fast breathing, chest pain, mental/mood changes, muscle weakness, numbness or tingling, or difficulty urinating. Very serious low blood counts or liver disease can occur, and that is why frequent blood tests are obtained at the beginning and then periodically during ongoing therapy. Seek immediate medical attention if you develop a fever, chills, easy bruising/bleeding, unusual fatigue, pale skin, yellowing eyes/skin, dark urine, or stomach/abdominal pain. Dapsone can cause a rash that is usually not serious. You should see your doctor if you get a rash to rule out a more serious skin reaction. There are some hypersensitivity reactions with a rash, fever, and liver changes that require stopping the dapsone.
Points to remember
It is important to have baseline blood testing before taking dapsone. You should take the dapsone as directed and have regular blood tests. You should notify your doctor if you get persistent symptoms listed above or develop a rash. If you are pregnant or are considering having a child, discuss this with your doctor before starting this medication.
Drug interactions
Avoid Coumadin or zidovudine if possible. There can be interactions with amprenavir, atazanavir, rifabutin, rifapentine, or Saquinavir.
Information to discuss with your primary care physician and other specialists
Be sure to notify your other physicians that you are taking this drug. Women taking this medication should discuss appropriate forms of birth control with their primary care physicians or gynecologists.
For more information
The Rheumatologic Dermatology Society (RDS) has compiled this list to give you a starting point for additional information. The RDS does not endorse or maintain these Web sites, and is not responsible for any information or claims provided on them. It is always best to talk with your dermatologist for more information and before making any decisions about your care.