Tsetse and trypanosomiasis

Are there drugs to cure Sleeping Sickness and Nagana?

Nagana
Trypanocidal drugs for use in cattle are limited to the salts of three compounds:-

• Isometamidium chloride (Samorin® /Trypamidium®, Mérial; Veridium®, Sanofi).

• Homidium bromide (Ethidium®, Laprovet) and homidium chloride (Novidium®, Mérial) and;

• Diminazene aceturate (Berenil®, Hoechst; Veriben®, Sanofi; and various other generic formulations),

Diminazene aceturate is the most widely used chemotherapeutic drug. It has virtually no prophylactic activity (Leach and Roberts, 1981).

The homidium salts are used mainly for chemotherapy, but they do have some prophylactic activity.

Isometamidium chloride is mainly used as a chemoprophylactic drug, but it too has some chemotherapeutic activity.

Sleeping sickness
While there are no drugs suitable for preventing sleeping sickness, there are drugs that can be used to treat it.

Pentamidine isothionate and suramin are the drugs of choice to treat the early haemolymphatic stage of West and East African trypanosomiasis, respectively.

Melarsoprol is the drug of choice for late-stage disease where there is central nervous system involvement.

Recently, eflornithine has been licensed for use to treat late-stage Sleeping Sickness. Eflornithine provides an alternative drug for the treatment of gambiense Sleeping Sickness, the form of sleeping sickness that occurs in West and Central Africa. For the rhodesiense form that occurs in East and southern Africa, there is no alternative treatment.

References
Leach, T.M. & Roberts, C.J. (1981). Present status of chemotherapy and chemoprophylaxis of animal trypanosomiasis in the eastern hemisphere. Pharmacology & Therapeutics 13, 91 – 147.