Papaverine as a replacement for pentoxifylline to select thawed testicular or epididymal spermatozoa before ICSI

Pentoxifylline has been used to improve sperm motility in Assisted Reproductive Technology mainly by initiating sperm motility in immotile spermatozoa samples obtained surgically. Indeed, as Intracytoplasmic Sperm Injection leads to very poor results when using immotile gametes, pentoxifylline gives better results by easing the selection of viable sperm mobilized after incubation. In 2011, the French Haute Autorité de santé decided that pentoxifylline used for in vivo purpose proposed Insufficient Medical Service and pentoxifylline was thus withdrawn from the French materia medica. We here assessed the efficacy on spermatozoa motility and the safety of papaverine, another phosphodiesterase inhibitor, for the replacement of pentoxifylline.

Sixteen frozen-thawed epididymal or testicular samples displaying no or very poor spontaneous motility (≤5% total motility) were subjected to both pentoxifylline (3.6mM) and papaverine (93μM). A duplicate Mouse Embryo Assay and an In Vitro Fertilization Mouse Assay in duplo were used to discard any toxic effect of papaverine.

Papaverine gave better results than pentoxifylline (mean total motility: 27% vs 23%, P<0.05). No Effect Level were observed in the two different Mouse Embryo Assays performed.

Papaverine is a useful tool to replace pentoxifylline in ICSI programs to select viable spermatozoa in frozen-thawed sperm samples displaying no or very poor motility.