Mifepristone

UNDER REVIEW (September 2016)

Mechanism of Action:

Progesterone antagonist. Blocks the action of progesterone on the superficial endometrium of the uterus, hence causes its decay and shedding. As a result, the blastocyst (fertilized egg) does not get the necessary nutrition, and is unable to attach to the uterus. Partial progesterone receptor agonist – increases sensitivity of uterus to prostaglandins and dilates the cervix.

Lecture and CAL materials:

  • RU 486 ®

Gemeprost

UNDER REVIEW (September 2016)

Mechanism of Action:

Prostaglandin E1 analogue. Causes cervical dilatation by activating collagenase in cervix (cervical ripening). Also causes uterine contractions. Gemeprost acts on PGE2 receptors in myometrium. Contraction causes expulsion of uterine contents.

Lecture and CAL materials:

  • Lecture:

Misoprostol

Indications:

  • Gastric protection during therapy with NSAIDs
  • Therapeutic abortion (with the anti-progestogen agent mifepristone and usually methotrexate)
  • Can be used in induction of labour

Mechanism of Action:

Prostaglandin E (EP) receptor agonist. EP receptors are seven-transmembrane G-protein-coupled receptors.

Lecture and CAL materials: (under review)