Impact of piroxicam β-cyclodextrin on the efficacy of the intrauterine device in a rat model

Abstract

Objective To elucidate the effect of piroxicam β-cyclodextrin (PβCD), a non-steroidal anti-inflammatory drug (NSAID), on the efficacy of the intrauterine device (IUD) in a rat model.Methods Forty nulliparous female Wistar rats were allocated to one of four groups, comprising each 10 of these animals. Group I: neither IUD nor medication; group II: IUD, but no medication; group III: IUD and PβCD; and group IV: PβCD only. In groups II and III, a string of 3/0 silk suture of 2 cm long was transcervically placed in one of the horns of the bicornuate uterus of the rat. Rats in group III were treated during the 18 days following IUD placement with 3 mg/kg/day PβCD administered via a feeding tube; group IV received PβCD for the same length of time, but had no IUD inserted. The rats were then mated. Thereafter, vaginal smears were taken and assessed daily, in the early morning, for the presence of spermatozoa. The day when spermatozoa were detected was considered to be the first day of gestation. On gestational day 19, both uterine horns of all rats were evaluated for the presence and number of embryos.Results In group II, mean embryo counts in the horn with or without IUD were 1.0 ± 0.2 and 4.5 ± 0.3, respectively (p < 0.01). The comparison of group II with group I showed that the presence of an IUD in one horn did not affect the mean embryo counts in the contralateral horn (4.5 ± 0.3 versus 5.1 ± 0.9, p > 0.05). In groups II and III, mean numbers of embryos in the horn with IUD were 1.0 ± 0.2 and 2.7 ± 0.4, respectively (p < 0.01). No difference in the mean embryo counts was observed between group I (5.1 ± 0.9) and IV (4.8 ± 0.9; p > 0.05).Conclusions The IUD had a contraceptive effect in the rat model. The IUD in one horn did not affect the number of embryos in the contralateral horn. In this model, IUDs appear to exert a local effect, i.e. counteracted by PβCD. This drug had no adverse effect on the fertility of rats without IUD in situ.