Aglepristone: A review on its clinical use in animals.

Aglepristone (RU 46534) is a competitive progesterone antagonist that is indicated for the treatment of various progesterone-dependent physiological or pathologic conditions. Aglepristone has proven to be an effective means of terminating pregnancy in most species. When used to induce parturition, aglepristone was effective in all cases in the bitch, cow, and goat, with no apparent adverse effects on neonatal health or milk production. When used to schedule an elective cesarean section, aglepristone treatment was deemed safe for dams and puppies, providing that the ovulation date had been accurately assessed at the time of breeding. Irrespective of the stage of pregnancy at injection, treatment with aglepristone has no apparent negative effects on subsequent fertility. Aglepristone is also a safe and relatively effective means of treating pyometra. However, given the high level of septic risk and the likelihood of rapid deterioration, such therapy is not recommended in emergency situations. Treatment of feline fibroadenomatosis using aglepristone has given promising results, but repeat treatment may be necessary in cats previously treated with long-acting progestagens. The use of aglepristone in other progesterone-dependent diseases has yet to be fully evaluated but may prove valuable, especially in the treatment of insulin-resistant diabetes mellitus, acromegaly, and the treatment of some vaginal tumors in the bitch.