An in vivo evaluation of the induction of abnormal sperm morphology by sulphamethoxypyridazine: pyrimethamine (Metakelfin).

The effects of sulphamethoxypyridazine: Pyrimethamine (Metakelfin) a combination antimalarial drug on mouse sperm head morphology were evaluated in University of Ibadan Veterinary F1 mice. Five different dose levels of 3.85:0.19; 7.7:0.38; 15.4:0.76; 23.1:1.13 and 30.8:1.54 mg kg(-1) body weight of sulphamethoxypridazine:pyrimetamine, respectively were administered to the animals by a schedule of 5 consecutive daily intraperitoneal (i.p.) injections. The sperm of the mice from the cauda epididymis were examined 5 weeks after treatment. Metakelfin induced sperm head abnormalities; however, of the 5 doses sampled; only the 7.7:0.38 mg kg(-1) dose, corresponding to 0.5x the human therapeutic dose (HTD0), gave a statistically significant (p > 0.05) increase over the negative control value of 2.53% abnormality. All the other dose level treatments did not yield statistically significant increase over the negative control value. The 15.4:0.77 mg kg(-1) dose showed 3.5% abnormality and fewer abnormalities than the preceding lower dose. The drug is probably not mutagenic as induction of sperm head abnormality was not dose dependent.