Anti-epileptic drugs affect fertility

Men with epilepsy often have fertility problems, which can be worsened by drugs used to prevent the seizures. If fertility problems emerge in men with treated epilepsy, semen analysis should be conducted and if abnormalities are found, alternative drug treatment should be considered. According to researchers, epilepsy is associated with reduced fertility, hormone disorders and sexual dysfunction. Their goal was to tease out the effects due to epilepsy and those due to anti-epileptic drugs. The researchers from the University of Bonn, Germany, studied 200 men with epilepsy treated with no more than one anti-epileptic drug, and compared them with 105 healthy 'control' subjects. It was found that although total testosterone levels were not significantly affected by epilepsy, free testosterone levels were higher in control subjects. Both forms of the hormone were lower in those with temporal lobe epilepsy than in those with other forms of the condition. The anti-epileptic drug carbamazepine was tied to significantly lower levels of testosterone than those seen with another anticonvulsant drug, valproate. Carbamazepine may therefore have the potential to aggravate the negative effects of temporal lobe epilepsy on testicular testosterone production. Valproate treatment appeared to have no effect on sperm cell function in those with temporal lobe epilepsy, but carbamazepine was associated with abnormal levels of hormones involved in sperm production. Epilepsy, especially temporal lobe epilepsy, adversely affects testicular endocrine function, but how much this reflects an impairment of fertility remains unclear.

Meanwhile, another group of researchers from the University of Oulu in Finland evaluated the reproductive health of 60 men with epilepsy treated with valproate, carbamazepine or oxcarbazepine, and a comparison group of 41 men. Abnormal sperms were more frequently seen in those with epilepsy. It was found that carbamazepine or partial epilepsy may affect sperm concentration, morphology, and motility. Valproate or generalized epilepsy may be associated with a high number of spermatozoa with abnormal morphology and motility, and oxcarbazepine may be associated with abnormal morphology of sperm. Valproate was also linked to reduced testicular volume, which was associated with abnormal sperm but not with serum hormone levels.These two studies give strategic direction for further research in the area of sexual function in men with epilepsy.