African Trypanosomiasis Medication

Updated: Apr 11, 2016
  • Author: Randy O Odero, MB, ChB; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Medication

Medication Summary

The type of drug treatment used depends on the type and stage of African trypanosomiasis (sleeping sickness)—that is, whether it is East African or West African and whether it is stage 1 (early/hemolymphatic) or stage 2 (late/neurologic).

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Anthelmintics

Class Summary

Biochemical pathways in the parasite are sufficiently different from those in the human host to allow selective interference by chemotherapeutic agents in relatively small doses.

Suramin

Suramin is an antiparasitic agent given intravenously (IV) in early-stage African trypanosomiasis and onchocerciasis. It is a polysulfonated naphthylamine derivative of urea. Suramin is trypanocidal and works by inhibiting parasitic enzymes and growth factors. It is highly bound to serum proteins and thus crosses the blood-brain barrier poorly. Serum levels are approximately 100 µg/mL. Suramin is more effective and less toxic than pentamidine. The drug is excreted in the urine at a slow rate.

Melarsoprol

Melarsoprol is a CDC anti-infective agent. It is a trivalent arsenical agent used in the late (neurologic) stage of African trypanosomiasis. It is trypanocidal, inhibiting parasitic glycolysis. Melarsoprol is water-insoluble and has a half-life of 35 hours. Serum levels are in the range of 2-5 µg/mL, but CSF levels are 50-fold lower. Melarsoprol is primarily excreted by the kidneys. Clinical improvement is usually observed within 4 days after starting the drug. Parasitemia is cleared in as many as 90-95% of cases. However, the drug can be toxic and even fatal in 4-6% of cases.

Studies have demonstrated the effectiveness of 10-day melarsoprol treatments for late-stage African trypanosomiasis. In addition, melarsoprol resistance has become a concern in the Congo and Uganda; as many as 30% of cases do not respond to the drug.

Eflornithine (Vaniqa)

Eflornithine is recommended for treatment of patients with West African trypanosomiasis, especially in the late (neurologic) stage. It is a selective and irreversible inhibitor of ornithine decarboxylase, which is a critical enzyme for DNA and RNA synthesis. It is used for patients in whom melarsoprol fails and is generally better tolerated and less toxic than arsenic drugs. The initial response time is 1-2 weeks. Eflornithine is available via the World Health Organization.

Pentamidine isethionate (Pentam)

Pentamidine isethionate is an antiprotozoal agent typically used for early (stage 1) African trypanosomiasis, as well as for Pneumocystis carinii pneumonia and leishmaniasis. It works by inhibiting dihydrofolate reductase enzyme, thereby interfering with parasite aerobic glycolysis.

Because of poor gastrointestinal absorption, pentamidine is administered IV or intramuscularly and is strongly bound to tissues, including the spleen, liver, and kidneys. Clinical improvement is usually noted within 24 hours of injection, and a cure rate exceeding 90% has been reported. Pentamidine does not penetrate the blood-brain barrier effectively and thus does not treat central nervous system infection.

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