Ribonucleotide reductase, an iron requiring enzyme necessary in the production of deoxyribonucleotides required for replication in cell division and proliferation is induced during the S phase of the cell cycle. We have compared the trypanocidal properties of four antibiotics that show bactericidal activities by destabilizing ribosome-mRNA complex to inhibit protein synthesis. Tetracycline and oxytetracycline that have iron chelating properties extended the lifespan of trypanosome infected rats from 6 and 5 days of control to 15 and 12 days respectively while chloramphenicol and streptomycin that have no iron chelating properties could not extend the lifespan of infected rats. We confirm our earlier report that iron chelation plays a prominent role in the tetracycline management of African trypanosomosis.