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mifepristone / RU486

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  • a synthetic steroid antiprogestogen used in the termination of pregnancy in the 1st 49 days of gestation
  • as not all women will miscarry with mifepristone alone, they are usually given the prostaglandin misoprostol 36-48hrs (buccal dose of 800mcg) after the dose
  • 89% of women with menstrual delay 35days or less (ie. <5wks pregnant) have a complete abortion with median time to abortion being 51hrs post-dose
  • can also be used to prepare for termination of pregnancy in the 2nd trimester, but 30% will need surgical evacuation in the 2nd trimester even with dual Rx with misoprostol
  • usual dose: 200mg
  • not recommended for women with liver or renal failure
  • ectopic pregnancy is a C/I
  • also has some action on glucocorticoid receptors thus adrenal failure is a C/I, and those on corticosteroids may need to increase their dose
  • combination with misoprostol commonly causes nausea, vomiting and diarrhoea, plus the expected vaginal bleeding of miscarriage which can sometimes warrant blood transfusion
  • it has also been shown to increase the life span of female flies and worms who have mated apparently by blocking the male's sex protein which changes metabolic pathways in the females1)
mifepristone.txt · Last modified: 2020/07/12 12:55 by gary1