The Sound of Evolution
Mifepristone
Mechanism of action:
Mifepristone is a progesterone receptor antagonist and also has glucocorticoid receptor antagonist activity. Mifepristone binds to the progesterone receptor with high affinity but cannot activate its physiological function, thereby blocking progesterone receptor signaling and its downstream effects. Mifepristone also binds to the glucocorticoid receptor with high affinity, blocking the physiological actions of cortisol without affecting cortisol concentration.
Reference(s):
1. Fiala C et al. (2006). Review of medical abortion using mifepristone in combination with a prostaglandin analogue. Contraception.
2. Heikinheimo O et al. (2003). The pharmacokinetics of mifepristone in humans reveal insights into differential mechanisms of antiprogestin action. Contraception.
3. Chabbert-Buffet N et al. (2005). Selective progesterone receptor modulators and progesterone antagonists: mechanisms of action and clinical applications. Hum Reprod Update.