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What is dapsone?

Dapsone is a medicine used to prevent or treat infections, such as Pneumocystis carinii pneumonia (also called PCP). It is used for patients who do not tolerate SMX/TMP (Septra® or Bactrim®). Dapsone is also used to treat some skin diseases. It is available in the following forms; all are taken by mouth:

  • A white 25-mg tablet in individual tablet packs (called blister packs)
  • A white 100-mg tablet in blister pack
  • A 2 mg/mL liquid suspension made by the pharmacy

Possible side effects of dapsone


  • Nausea and vomiting
  • Stomach upset

Later (more than a day after treatment starts)

  • Stomach upset
  • Loss of appetite
  • Ringing in the ears
  • Blurred vision
  • Temporary changes in liver function
  • Low blood counts
  • Trouble sleeping
  • Muscle weakness
  • Tingling, pain, or numbness in the hands or feet
  • Headache
  • Feeling dizzy or nervous
  • Skin more sensitive to the sun

These are the most common side effects, but there may be others (see next page). Please report any side effects to the doctor, nurse, or pharmacist.

If you have any of the following side effects, tell your doctor right away by calling 901-595-3300. If you are outside Memphis, dial toll-free 1-866-2STJUDE (1-866-278-5833) and press 0. These symptoms could mean that you need to stop taking dapsone right away.

  • Yellowing of eyes or skin
  • Dark yellow or brown urine
  • Bluish fingernails or lips
  • Fever, chills, or sore throat
  • Blood in the urine
  • Decrease or increase in the amount of urine passed
  • Unusual bleeding or bruising
  • Rash

Special instructions for dapsone

  • To provide the best protection from PCP, you must take dapsone exactly as your doctor tells you. Taking a smaller amount or missing a dose decreases protection. Taking more medicine does not increase protection.
  • Store the dapsone tablets at room temperature. Leave the blister pack intact until ready to give a dose. The tablet must be protected from light.
  • Store the dapsone liquid in the refrigerator. Do not use after the expiration date printed on the label.
  • Shake the dapsone liquid well before you take each dose.
  • Blood will be drawn regularly to check blood counts and to check for liver function changes.
  • Some medicines may affect the way dapsone works. Always tell your doctor which medicines you are currently taking. Also tell the doctor if you start taking any new medicines while you are taking dapsone.
  • Dapsone makes your skin more sensitive to sunlight. Wear sunscreen lotion and clothing that protects your skin when outside during daylight hours.
  • Dapsone passes into breast milk. Because this medicine may cause serious harm to a nursing infant, women who are taking dapsone should not breast feed a baby.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

ATTENTION: If you speak another language, assistance services, free of charge, are available to you. Call 1-866-278-5833 (TTY: 1-901-595-1040).

ATENCIÓN: si habla español, tiene a su disposición servicios gratuitos de asistencia lingüística. Llame al 1-866-278-5833 (TTY: 1-901-595-1040).

تنبيه: إذا كنت تتحدث باللغة العربية فيمكنك الاستعانة بخدمات المساعدة اللغوية المتوفرة لك مجانا. .يرجى الاتصال بالرقم. 5833-278-866-1  (الهاتف النصي: 1040-595-901-1).