FPIN's Help Desk Answers
Misoprostol Dosing for First-Trimester Abortion
Am Fam Physician. 2020 Sep 1;102(5):online.
What is the most effective way to dose misoprostol (Cytotec) for evacuating the uterus of first-trimester products of conception?
Vaginal, oral, and sublingual misoprostol in single doses of 600 to 800 mcg are equally effective for promoting completed abortion in patients with an incomplete first-trimester spontaneous abortion. (Strength of Recommendation [SOR]: A, based on consistent meta-analyses of randomized controlled trials [RCTs].) When combined with mifepristone (Mifeprex), a single 800-mcg dose of vaginal or buccal misoprostol is more effective than a single 800-mcg dose of oral misoprostol for first-trimester therapeutic abortion. (SOR: A, based on a meta-analysis of RCTs.) Vaginal dosing is better tolerated than oral, buccal, or sublingual dosing. (SOR: A, based on meta-analyses of RCTs.)
INCOMPLETE SPONTANEOUS ABORTION: SINGLE-DOSE MISOPROSTOL
Two 2017 systematic reviews evaluating misoprostol in women with incomplete first-trimester spontaneous abortion found that doses of at least 600 mcg were equally effective for uterine evacuation, regardless of the route of administration. The first review evaluated all options for the medical treatment of spontaneous abortion and included five RCTs of single-dose misoprostol regimens.1 One RCT (n = 198) comparing vaginal and oral misoprostol, 800 mcg, found similar success rates for complete uterine evacuation (relative risk [RR] = 0.94; 95% CI, 0.76 to 1.16). Two RCTs (n = 464) compared different doses of oral misoprostol: 600 mcg vs. 1,200 mcg. Both doses resulted in similar rates of complete uterine evacuation (RR = 1.00; 95% CI, 0.93 to 1.07). Two additional RCTs (n = 358) compared sublingual misoprostol, 400 to 600 mcg, with oral misoprostol, 600 mcg. Oral and sublingual administration produced similar rates of complete uterine evacuation (RR = 0.99; 95% CI, 0.94 to 1.05).
The second review 2 evaluated 18 RCTs (N = 1,802), only one of which was included in the first review.
1. Kim C, Barnard S, Neilson JP, et al. Medical treatments for incomplete miscarriage. Cochrane Database Syst Rev. 2017;(1):CD007223.
2. Wu HL, Marwah S, Wang P, et al. Misoprostol for medical treatment of missed abortion: a systematic review and network meta-analysis. Sci Rep. 2017;7(1):1664.
3. Kulier R, Kapp N, Gülmezoglu AM, et al. Medical methods for first trimester abortion. Cochrane Database Syst Rev. 2011;(11):CD002855.
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