Melarsoprol Injectable: Dosing and Precautions

Therapeutic action

Trypanocide (arsenical derivative).

Indications

Meningoencephalitic stage of African trypanosomiasis due to T. b. gambiense and T. b. rhodesiense.

Forms and strengths, route of administration

Due to high toxicity and numerous adverse effects, patients must be treated in hospital under close medical supervision.

• 180 mg in 5 ml ampoule (36 mg/ml), 3.6% solution in propylene glycol, for slow IV injection.
• Do not administer by IM or SC injection.

Dose and duration

• Child and adult: 2.2 mg/kg, maximum 5 ml, once daily for 10 days.

Contra-indications, adverse effects, precautions

• May cause reactive encephalopathy with repeated or prolonged seizures, coma, and mental disorders, usually between the fifth and eighth day of treatment but sometimes later.
• May cause arsenical reactions such as headache, fever, tachycardia, hypertension, jaw pain, and neurological disorders with hyperreflexia.
• May also cause gastrointestinal disturbances, skin reactions, peripheral neuropathy, haematological disorders including haemolytic anaemia in G6PD deficiency and agranulocytosis, hepatic or renal impairment, myocardial damage, and severe local reactions if extravasation occurs.
• As propylene glycol can dissolve plastic, syringes should be prepared just before injections.
• Pregnancy: contraindicated.
• Oral prednisolone is frequently associated during the course of treatment.
• For the meningoencephalitic stage of gambiense trypanosomiasis, the treatment of choice is nifurtimox plus eflornithine (NECT).