Low-dose lisinopril in normotensive men with idiopathic oligospermia and infertility: a 5-year randomized, controlled, crossover pilot study.

The outcomes of drug treatment for male infertility remain conjectural, with controversial study results. Our pilot study employed a randomized, placebo-controlled, crossover methodology with intention-to-treat analysis. Thirty-three men with idiopathic oligospermia were randomized to start either daily oral lisinopril 2.5 mg (n = 17) or daily oral placebo (n = 16). Lisinopril was found to cause a normalization of seminal parameters in 53.6% of the participants. Although the mean ejaculate volume was unchanged (P ≥ 0.093), the total sperm cell count and the percentage of motile sperm cells increased (P ≤ 0.03 and P < 0.001, respectively), whereas the percentage of sperm cells with abnormal morphology decreased (P ≤ 0.04). The pregnancy rate was 48.5%, and there was no serious adverse drug event. It is concluded, albeit cautiously, that prolonged treatment with 2.5 mg/day of oral lisinopril may be well tolerated in normotensive men with idiopathic oligospermia, may improve sperm quantity and quality, and may enhance fertility in approximately half of those treated.