Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

Information presented on common adverse reactions relies solely on data from US studies, because rates reported in non-US studies were markedly lower and are not likely generalizable to the US population. In three US clinical studies totaling 1,248 women through 70 days gestation who used mifepristone 200 mg orally followed 24-48 hours later by misoprostol 800mcg buccally, women reported adverse reactions in diaries and in interviews at the follow-up visit. These studies enrolled generally healthy women of reproductive age without contraindications to mifepristone or misoprostol use according to the Mifepristone tablets, 200 mg product label.Gestational age was assessed prior to study enrollment using the date of the woman's last menstrual period, clinical evaluation, and/or ultrasound examination.

About 85% of patients report at least one adverse reaction following administration of Mifepristone tablets, 200 mg and misoprostol, and many can be expected to report more than one such reaction. The most commonly reported adverse reactions (>15%) were nausea, weakness, fever/chills, vomiting, headache, diarrhea, and dizziness (see Table 1). The frequency of adverse reactions varies between studies and may be dependent on many factors including the patient population and gestational age.

Abdominal pain/cramping is expected in all medical abortion patients and its incidence is not reported in clinical studies. Treatment with Mifepristone tablets, 200 mg and misoprostol is designed to induce uterine bleeding and cramping to cause termination of an intrauterine pregnancy. Uterine bleeding and cramping are expected consequences of the action of Mifepristone tablets, 200 mg and misoprostol as used in the treatment procedure. Most patients can expect bleeding more heavily than they do during a heavy menstrual period [see  Warnings and Precautions ( 5.2) ]. 

Table 1 lists the adverse reactions reported in US clinical studies with incidence >15% of women.

Table 1 Adverse Reactions Reported in Women Following Administration of Mifepristone (oral) and Misoprostol (buccal) in US Clinical Studies

One study provided gestational-age stratified adverse reaction rates for women who were 57-63 and 64-70 days; there was little difference in frequency of the reported common adverse reactions by gestational age.

Information on serious adverse reactions was reported in six US and four non-US clinical studies, totaling 30,966 women through 70 days gestation who used mifepristone 200mg orally followed 24-48 hours later by misoprostol 800mcg buccally. Serious adverse reaction rates were similar between US and non-US studies, so rates from both US and non-US studies are presented. In the US studies, one studied women through 56 days gestation, four through 63 days gestation, and one through 70 days gestation, while in the non-US studies, two studied women through 63 days gestation, and two through 70 days gestation. Serious adverse reactions were reported in <0.5% of women. Information from the US and non-US studies is presented in Table 2.

Table 2 Serious Adverse Reactions Reported in Women Following Administration of Mifepristone (oral) and Misoprostol (buccal) in US and Non-US Clinical Studies