Mifepristone adverse effects

In a double-blind, randomized, controlled trial, 896 healthy women requesting a medical abortion (57-63 days gestation, mean age 25 years) were randomized to a single oral dose of mifepristone 200 or 600 mg, both followed in 48 hours by gemeprost 1 mg vaginally (2). The complete abortion rates were similar with the lower and higher doses of mifepristone (92 versus 92%). The incidences of adverse effects were similar, with the exception of nausea at 1 week, which was less frequent in the low-dose group (3.6 versus 7.6%). 

Whatever the adverse effects of mifepristone, the risks have to be looked at realistically and compared with those of the alternatives available to a particular woman in particular circumstances. Particularly in rural areas in developing countries, the risks of surgical and non-professional abortion are high, whereas, as has been shown in a study in rural India, a regimen of mifepristone plus misoprostol can be used as effectively and safely, through family planning clinics and country hospitals, as in a European environment (2). 

The effective oral doses of mifepristone are 100-600 mg, and at any dose the bulk of recipients abort. Of 150 healthy women who received the higher dose, 131 attained a complete abortion. Three women reported bleeding for more than 2 weeks after abortion 16 women had a reduced hemoglobin concentration of under 11 g/dl, justifying iron therapy. Other adverse effects were uterine contractions and pelvic pain (n = 4), transient asthenia (n = 3), and nausea (n = 2) (5). These findings seem to be typical, even though dosage schemes have varied as little as 100 mg orally has been used successfully with similar adverse effects (SED-12,1037 6). 

Various anti-progestogenic routines for the termination of pregnancy continue to be compared. Of 354 women who were given mifepristone 200 mg in the clinic and then sent home with two tablets of misoprostol 200 micrograms to take 48 hours later, 324 (91.5%) had a successful termination (7). The most common adverse effects were pain or cramps (93%) and nausea (67%), followed by weakness (55%), headache (46%), and dizziness (44%). Overall acceptability of the regimen was high 63% of women reported that it was very satisfactory and another 23% found it satisfactory . There were no serious complications and the simplified routine, with a much reduced duration of hospital care, was considered acceptable. 

There has sometimes been reluctance to use higher doses of mifepristone, because of a supposedly greater risk of severe adverse effects. However, in a randomized comparison of a single oral dose of mifepristone (either 200 mg or 600 mg) followed 48 hours later by oral misoprostol 400 pg the two regimens produced identical results as regards the induction of abortion and the incidence of adverse effects (22). 

The antiprogesterone mifepristone, almost exclusively used as an abortifacient, has also been tried as a post-coital contraceptive (11). In one randomized comparative trial, a single dose of mifepristone 600 mg was at least as effective as the usual hormonal method (12). Women who took mifepristone had lower rates of adverse effects, particularly nausea and vomiting, but their next menstrual period was more likely to be delayed. In another randomized trial, both methods were equally effective (SEDA-16, 466). The use of an estrogen + a progestogen had a higher total incidence... 

NSAIDs (nonsteroidal antiinflammatory drugs) Isolated cases of adverse neurological side effects have been seen with naproxen or phenylbutazone given with misoprostol. Misoprostol also increases the abdominal pain and other side effects of diclofenac and indometacin (indomethacin). Paracetamol (acetaminophen) intensifies pain if given with mifepristone and sulprostone used to induce abortion. 

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