Mifepristone for the prevention of breakthrough bleeding in new starters of depo-medroxyprogesterone acetate

Mifepristone alters expression of endometrial steroid receptors and their cofactors in new users of medroxyprogesterone acetate

“…Recently, the PR antagonist, mifepristone, was demonstrated to decrease the incidence of breakthrough bleeding in users of levonorgestrel (Norplant; Leiras Oy, Turku, Finland) (4 -6) and in users of DMPA (7). The exact mechanisms by which mifepristone reduces bleeding are not understood fully, although it was shown to block the biologic effects of progesterone by binding with high affinity to the PR (8).…”

Using phytoestrogens as aprophylaxis against irregular uterine bleeding possibly occurring while using Depot-medroxyprogesterone acetate (DMPA) as a contraceptive method

“…17 More recent evidence of short-term benefit of mefenamic acid use in already established bleeding has been published. 15 but there is no evidence in literature on its use as a prophylaxis.…”

“…Based on more recent evidence 15 for women who have a contraindication to COC use then mefenamic acid (500 mg twice or three times daily for 5 days) may be considered to attenuate a bleeding episode but there is no evidence that this approach has an effect on bleeding patterns in the longer term. A small randomised controlled trial 17 suggested that there is some evidence that a cox-2 inhibitor (valdecoxib) is effective in the treatment of uterine bleeding with DMPA, however the use of cox-2 inhibitors for this purpose is unlicensed in some countries.…”

Stimulation of epithelial repair is a likely mechanism for the action of mifepristone in reducing duration of bleeding in users of progestogen-only contraceptives

“…Importantly, treatment with EE renders the idea of a progestogen only and therefore oestrogen-free contraceptive regime futile. By contrast, short-term administration of the anti-progestogen, mifepristone, has been successful in reducing bleeding days in women using P-only contraception in a number of independent studies (Cheng et al 2000, Glasier et al 2002, Jain et al 2003, Massai et al 2004, Weisberg et al 2006. A further reduction in the bleeding days was observed upon mifepristone treatment in conjunction with oestrogen (Weisberg et al 2006).…”