Tadalafil as an in vitro sperm motility stimulant

Tadalafil (Cialis) is a known oral selective phosphodiesterase-5 inhibitor used widely in the management of erectile dysfunction. To assess its ability on human sperm motility in vitro, 70 asthenozoospermic semen specimens delivered by masturbation were investigated. Semen samples were divided equally into four tubes, one as a control and to the others tadalafil dissolved solution was added in vitro in three different concentrations (4.0, 1.0, 0.5 mg ml(-1) respectively). The tubes were incubated and were followed up for sperm motility per cent changes for 0.5, 1, 2, 3 h. It was found that the concentration used played an important role in the degree of sperm enhancement. Specimens treated with 4 mg ml(-1) tadalafil solution demonstrated a significant decrease in sperm motility compared with the controls. Specimens treated with 1.0 mg ml(-1) solution demonstrated significant increase in sperm progressive forward motility. Specimens treated with 0.5 mg ml(-1) solution demonstrated significant increases in sperm motility but lower than that of 1 mg ml(-1) concentration. It is concluded that in vitro use of tadalafil solution in special concentration has a significant stimulatory effect on asthenozoospermic sperm motility.