We tested the antimicrobial drug Oxytetracycline-HCl against the infections of the protozoan parasite Trypanosoma brucei
which causes the disease African Trypanosomosis. Oxytetracycline-HCl was used to treat rats infected with the disease at early and late stages of infections. Prophylactic administration was also carried out. The results showed that prophylactic treatment only did not inhibit the proliferation of the parasite but with continued administration kept parasitaemia low. Both prophylactic and early stage treatment of the infection extended the lifespan of the animals. Oxytetracycline-HCl was ineffective for the treatment of the late stage of infection. Oxytetracycline with its iron chelating property could be a useful inhibitor of ribonucleotide reductase, a cell cycle regulated enzyme that in turn regulates cell proliferation. Our experiment suggests that oxytetracycline-HCl could be a good management therapy for the African trypanosomosis if administered at the early stage of infection.