Reproductive toxic effects of Topamax ingestion in female Sprague-Dawley rats.

PURPOSE: The objectives of this study is to investigate the toxic effects of Topamax (100 mg/kg/body weight) on the reproductive system after administration to female Sprague-Dawley rats weighing 250-300 g for two time periods 4 and 12 weeks.

METHODS: Twenty adult female rats were divided into two groups and exposed to Topiramate diet at a concentration of 100 mg/kg/body weight for two periods of time. First group containing 10 rats received treatment for 4 weeks and a second group of 10 rats received the same dose of treatment for a period of 12 weeks and compared with twenty non-exposed female rats received vehicle treatment. Female rats were allowed mating with males after 10 days prior to the last administration dose. Animals were autopsied under light anesthesia after mating and several parameters were determined including: number of pregnant rats, body and reproductive organ weight, number of implantation sites, viable fetuses, and resorption sites. Assessment of pregnancies in females was measured and the significance of these results was calculated using student's 't' and Chi-square tests.

RESULTS: The effect of Topamax exposure on fertility was assessed in terms of pregnant rats number, implantation sites, viable fetuses, and resorption sites. Exposure to Topamax for 4 weeks did not have much effect on fertility. Significant decrease in the relative ovarian weights and embryo weights in rats exposed to Topamax were observed. Exposure to Topamax for a 12 weeks resulted in a reduction in the percentage of pregnancies and in the number of implantation sites, when compared with controls in both treatment periods. Rats receiving 12 weeks treatment showed an increase in ovarian weights and a decrease in viable fetuses number. These results indicate that long-term exposure of female rats to Topamax causes adverse effects on the reproductive system and fertility.

CONCLUSION: The results of the current study suggest that ingestion of Topamax by adult female rats causes adverse effects on fertility and reproduction.