DAPSONE (Systemic)

Some commonly used brand names are:

In Canada?

• Avlosulfon

Generic name product may be available in the U.S.

Another commonly used name is DDS.

Category

• Antibacterial, antileprosy agent
• Antifungal, systemic
• Antiprotozoal
• Dermatitis herpetiformis suppressant

Description

Dapsone (DAP-sone), a sulfone, belongs to thefamily of medicines called anti-infectives.

Dapsone is used to treat leprosy (Hansen's disease) and to help controldermatitis herpetiformis, a skin problem. When it is used to treat leprosy,dapsone may be given with one or more other medicines. Dapsone may also beused for other conditions as determined by your doctor.

Dapsone is available only with your doctor's prescription, in the followingdosage form:

Oral
• Tablets (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For dapsone, the followingshould be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to dapsone or sulfonamides. Also tell your health care professionalif you are allergic to any other substances, such as foods, preservatives,or dyes.

Pregnancy?Studies have not been done in humans or animals.However, reports on the use of dapsone in humans have not shown that thismedicine causes birth defects or other problems.

Breast-feeding?Dapsone passes into the breast milk. Dapsone maycause blood problems in nursing babies with glucose-6-phosphate dehydrogenase(G6PD) deficiency. Breast-feeding may need to be stopped because of the risksto the baby.

Children?Although there is no specific information comparinguse of dapsone in children with use in other age groups, this medicine isnot expected to cause different side effects or problems in children thanit does in adults.

Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults or if they cause different side effectsor problems in older people. There is no specific information comparing useof dapsone in the elderly with use in other age groups.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingdapsone, it is especially important that your health care professional knowsif you are taking any of the following:

• Acetohydroxamic acid (e.g., Lithostat) or
• Antidiabetics, oral (diabetes medicine you take by mouth) or
• Furazolidone (e.g., Furoxone) or
• Methyldopa (e.g., Aldomet) or
• Nitrofurantoin (e.g., Furadantin) or
• Primaquine or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Quinine (e.g., Quinamm) or
• Sulfonamides (sulfa medicine) or
• Vitamin K (e.g., AquaMEPHYTON, Synkayvite)?Use of dapsone withthese medicines may increase the chance of side effects affecting the blood

• Dideoxyinosine (e.g., ddI, Videx)?Use of dideoxyinosine withdapsone may decrease the effectiveness of dapsone

Other medical problems?The presence of other medicalproblems may affect the use of dapsone. Make sure you tell your doctor ifyou have any other medical problems, especially:

• Anemia (severe) or
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency or
• Methemoglobin reductase deficiency?There is an increased riskof severe blood disorders and a decrease in red blood cell survival

• Liver disease?Dapsone may on rare occasion cause liver damage

Proper Use of This Medicine

For patientstaking dapsone for leprosy:

• To help clear up your leprosy completely or to keep it from comingback, it is very important that you keep taking thismedicine for the full time of treatment, even if you begin to feelbetter after a few weeks or months. You may have to take it every day foras long as 3 years or more, or for life. If you stop taking this medicinetoo soon, your symptoms may return.
• This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses.Also, it is best to take each dose at the same time every day. If youneed help in planning the best time to take your medicine, check with yourhealth care professional.

For patients taking dapsone for dermatitis herpetiformis:

• Your doctor may want you to follow a gluten-free diet. If you haveany questions about this, check with your doctor.

Dosing?The dose of dapsone will be different for differentpatients. Follow your doctor's orders or the directionson the label. The following information includes only the average dosesof dapsone. If your dose is different, do not changeit unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine.Also, the number of doses you take each day, the timeallowed between doses, and the length of time you take the medicine dependon the medical problem for which you are taking dapsone.

• For oral dosage form (tablets):
  • For Hansen's disease (leprosy):
    • Adults and teenagers?50 to 100 milligrams (mg) once a day;or 1.4 mg per kilogram (kg) (0.6 mg per pound) of body weight once a day.Dapsone should be taken with other medicines to treat Hansen's disease.
    • Children?Dose is based on body weight. The usual dose is 1.4mg per kg (0.6 mg per pound) of body weight once a day. Dapsone should betaken with other medicines to treat Hansen's disease.
  • For dermatitis herpetiformis:
    • Adults and teenagers?50 mg once a day to start. Your doctorwill increase your dose, up to 300 mg once a day, until your symptoms arecontrolled. Then your dose will be decreased to the lowest dose that willstill control your symptoms.
    • Children?Dose is based on body weight. The usual dose is 2mg per kg (0.9 mg per pound) of body weight once a day to start. Your doctorwill increase your dose until your symptoms are controlled. Then your dosewill be decreased to the lowest dose that will still control your symptoms.

Missed dose?You may skip a missed dose if it does not makeyour symptoms come back or get worse. If your symptoms do come back or getworse, take the missed dose as soon as possible. Then go back to your regulardosing schedule.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

It isvery important that your doctor check your progress at regular visits.

If your symptoms do not improve within 2 to 3 months (for leprosy), orwithin a few days (for dermatitis herpetiformis), or if they become worse,check with your doctor.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects.Although not all of these side effects may occur, if they do occur they mayneed medical attention.

Check with your doctor immediately if any ofthe following side effects occur:

More common

Back, leg, or stomach pains; bluishfingernails, lips, or skin; difficult breathing; fever; loss of appetite; pale skin; skin rash; unusual tiredness or weakness

Rare

Itching, dryness, redness, scaling, or peeling of the skin, orloss of hair; mood or other mental changes; numbness, tingling, pain, burning, or weakness in hands or feet; sore throat; unusual bleedingor bruising; yellow eyes or skin

Other side effects may occurthat usually do not need medical attention. These side effects may go awayduring treatment as your body adjusts to the medicine. However, check withyour doctor if any of the following side effects continue or are bothersome:

Rare

Headache; loss of appetite; nausea or vomiting; nervousness; trouble in sleeping

Other side effects not listed above may also occur in some patients. Ifyou notice any other effects, check with your doctor.

Additional Information

Once a medicine has been approvedfor marketing for a certain use, experience may show that it is also usefulfor other medical problems. Although these uses are not specifically includedin product labeling, dapsone is used in certain patients with the followingmedical conditions:

• Actinomycotic mycetoma
• Granuloma annulare
• Malaria (prevention of)
• Pemphigoid
• Pneumocystis carinii pneumonia
• Pyoderma gangrenosum
• Relapsing polychondritis
• Subcorneal pustular dermatosis
• Systemic lupus erythematosus

For patients taking this medicine for Pneumocystis cariniipneumonia (PCP):

• To help clear up PCP completely or to keep it from coming back, it is very important that you keep taking this medicine forthe full time of treatment.
• If you miss a dose of this medicine, take it as soon as possible.This will help keep a constant amount of medicine in the blood. However, ifit is almost time for your next dose, skip the missed dose and go back toyour regular dosing schedule. Do not double doses.
• If your symptoms do not improve within 1 week, or if they becomeworse, check with your doctor.

Other than the above information, there is no additional information relatingto proper use, precautions, or side effects for these uses.