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MELARSOPROL (Systemic)*†

Some commonly used brand names are:

  • Arsobal

Other commonly used names are Mel B and Melarsen Oxide-BAL .

*† Not commercially available in the U.S. and Canada.


  • Antiprotozoal, systemic


Melarsoprol (mel-AR-so-prol) is used to treat African sleeping sickness, a disease caused by parasites.

Melarsoprol is to be administered only in the hospital by or under the immediate supervision of your doctor. It is available in the following dosage form:

  • Parenteral
  • Injection (France)

Before Receiving This Medicine

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

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to melarsoprol. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies on effects in pregnancy have not been done in either humans or animals.

Breast-feeding—It is not known whether melarsoprol passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are receiving this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Although there is no specific information comparing use of melarsoprol in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of melarsoprol in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other medical problems—The presence of other medical problems may affect the use of melarsoprol. Make sure you tell your doctor if you have any other medical problems, especially:

  • Fever—Melarsoprol may increase the chance of side effects in patients with fever
  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency—Melarsoprol may increase the chance of side effects affecting the blood in patients with G6PD deficiency
  • Leprosy—Melarsoprol may cause the appearance of tender nodules or lumps on the legs (usually below the knees) in patients with leprosy

Proper Use of This Medicine

To help clear up your infection completely, it is important that you receive melarsoprol for the full time of treatment and on a regular schedule. It is also necessary for you to stay in the hospital while receiving this medicine so your doctor can check on your condition.

Dosing—The dose of melarsoprol will be different for different patients. The following information includes only the average doses of melarsoprol.

The dose you receive each day, the time allowed between doses, and the length of time you receive the medicine depend on the severity of the medical problem for which you are receiving melarsoprol .

  • For injection dosage form:
    • For African sleeping sickness:
      • Adults—Dose is based on body weight and must be determined by your doctor. The medicine is injected into a vein. The dose is given once a day for three days. Treatment can be repeated three or four times with an interval of one week in between courses of treatment.
      • Children—Dose is based on body weight and must be determined by your doctor. The medicine is injected into a vein. The dose is given once a day. Treatment is repeated at intervals of one to five days, for a total of nine to ten doses.

Precautions While Using This Medicine

Melarsoprol may cause stomach upset. To minimize this problem, you should not eat before receiving this medicine and should remain without food for at least 5 hours after treatment. Also, you should receive this medicine lying down and should remain in bed even after treatment.

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 may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

Chills; confusion; convulsions (seizures); fever; general feeling of illness or discomfort; headache; loss of consciousness; numbness, tingling, pain, or weakness of hands or feet; pain or swelling at injection site; restlessness; slurring of speech; stiffness of body; sweating; tremors

Less common

Cloudy urine; fever with or without chills; increased blood pressure; irregular heartbeat; red, thickened, or scaly skin; skin rash or itching; yellow eyes or skin


Black, tarry stools; blood in urine or stools; changes in skin color of face; fainting; fast or irregular breathing; pinpoint red spots on skin; puffiness or swelling of the eyelids or around the eyes; shortness of breath; sores, ulcers, or white spots on lips or in mouth; sore throat; swollen and/or painful glands; tightness in chest; trouble in breathing; unusual bleeding or bruising; unusual tiredness or weakness; wheezing

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

More common

Abdominal or stomach pain; diarrhea; joint pain; nausea; vomiting

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

Developed: 12/20/1994

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.