RU486: Mechanism of Action
RU486, or mifepristone, functions primarily as a progesterone receptor antagonist, inhibiting the effects of progesterone, a hormone essential for sustaining pregnancy. While it does not induce a significant biological response to progesterone, it exhibits weak anti-glucocorticoid and anti-androgenic properties. RU486 facilitates the opening of the cervix, triggers decidual degeneration, and promotes the release of uterine prostaglandins, which are crucial for uterine contractions. This medication enhances uterine receptivity to prostaglandins, ultimately leading to the expulsion of the fetus.
Dosage: RU486
The recommended dosage for mifepristone is 200 mg, taken orally. This should be followed by the administration of misoprostol, typically 800 mcg (four 200 mcg pills), 1–3 days later. Together, these medications effectively induce abortion by promoting uterine contractions and facilitating the expulsion of the pregnancy.
Contraindications: RU486
RU486 is contraindicated in several conditions, including:
- Presence of an intrauterine device (IUD)
- Ectopic pregnancy
- Breastfeeding
- Excessive alcohol consumption
- Blood coagulation disorders
- Adrenal insufficiency
- Inherited porphyrias
- Asthma
- Renal or hepatic failure
- Sickle cell anemia
- Hypertension or heart disease
It is crucial to seek a healthcare provider's approval before using this medication to avoid potential harmful effects.
Side Effects: RU486
While RU486 is effective in terminating pregnancies, it may also produce side effects. Common symptoms include vaginal bleeding and abdominal pain, which can usually be managed with NSAID pain relievers. Other potential side effects include:
- Diarrhea
- Uterine infections (bacterial or viral)
- Hot flashes
- Fever
- Gastroesophageal reflux
- Swelling of the face and larynx
- Rash
- Uterine rupture (rare)
Side effects can vary significantly among individuals due to differing immune responses and tolerances to the medication. Some women may experience unusual or heavy vaginal bleeding after taking RU486, with spotting potentially lasting beyond eight days and, in some case