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Summary of key misoprostol-only studies

The following table summarizes a number of influential studies investigating the efficacy of misoprostol as a single agent abortifacient. Please note that the sample-sizes reported in many of these studies have been relatively small and thus the conclusions should be interpreted with caution.

Study
Gestational age
Sample size
Route
Dosing schedule and protocol
Efficacy
Comments
Jain, et al [1].
< 56 days
125
PV
800µg of moistened misoprostol was administered vaginally. The dose was repeated every 24 hours up to three doses if the abortion failed to occur. This was a randomized, double blinded, placebo-controlled trial comparing the misoprostol-only regimen to a mifepristone/misoprostol regimen.
Total: 88%
After 1 dose: 72%
After 2 doses: 86%
After 3 doses: 88%
Mifepristone/misoprostol regimen was 95.7% effective.
Tang, et al [2].
< 12 weeks
50
PO
600µg of sublingual misoprostol was administered. The dose was repeated every 3 hours for a maximum for five doses.

Total: 86%
< 7 wks: 100%
< 9 wks: 88.9%

Mean # doses was 4.1
Mean vaginal bleeding time was 15 days
Carbonell, et al [3].
42-63 days
300
PV
1000µg of moistened misoprostol was self-administered vaginally by women (at home). The dose was repeated every 24 hours for a maximum of three doses.
Total: 93% complete abortion (69% w/in 24 hrs)
Mean vaginal bleeding time was 14.7 days
Bugalho, et al [4].
< 42 days
103
PV
800µg of moistened misoprostol was administered vaginally. The dose was repeated one week later if abortion was not complete.
After 1 dose: 87.1% (71.8% w/in 24 hrs)
After 2 doses: 92%
-
Ngai et al [5].
< 9 weeks
1) 40
2) 40
1) PV
2) PV
1) 800µg of moistened misoprostol was administered vaginally. The dose was repeated on Day 3 and Day 5.
2) 800µg of dry misoprostol was administered vaginally. The dose was repeated on Day 3 and Day 5.
1) Total: 85%
2) Total: 65%
40% of women said they would prefer surgical abortion
Carbonell, et al [6].
35-63 days
720
PV
800µg of moistened misoprostol was self-administered vaginally by women (at home). The dose was repeated every 24 hours for a maximum of three doses.
Total: 89.4% 
(65.4% w/ 1 dose)
Efficacy decreased with increased gestational age
Bebbington, et al [7]. Mid-trimester 1) 65
2) 49
1) PO
2) PV
1) 200µg of misoprostol was administered orally every hour for three hours. This was followed by 400µg every four hours for up to 24 hours.
2) 400µg of misoprostol was administered vaginally every four hours for 24 hours.
1) Total: 38.5%
2) Total: 85.7%
Study only allowed 24 hrs for a complete abortion to take place
Tang, et al [8].
13-20 weeks
18
PO
400µg of sublingual misoprostol was administered. The dose was repeated every 3 hours for a maximum of 5 doses.
Total: 100%
Median induction to abortion time was 11.6 hours
Jain, et al [9].
12-22 weeks
1) 47
2) 37
PV
PV
1) 200µg of misoprostol was administered vaginally every 6 hours for up to 48 hours.
2) 200µg of misoprostol was administered vaginally every 12 hours for up to 48 hours.
1) 80.9% aborted w/in 24 hours; 87.2% w/in 48 hours
2) 86.5% aborted w/in 24 hours; 89.2% w/in 48 hours
Complete abortion rate was greater with non-viable pregnancies


Citations in this section
[1] Jain J et al, 2002.
[2] Tang O et al, 2002.
[3] Carbonell et al, 2001.
[4] Bugalho A et al, 2000.
[5] Ngai S et al, 2000.
[6] Carbonell E et al, 1999.
[7] Bebbington et al, 2002.
[8] Tang O and Ho P, 2001.
[9] Jain J, Kuo J and Mishell D, 1999.

For the full bibliographic citations of all references listed in this section, please visit our reference section.



If you have questions about medication abortion, please visit our frequently asked questions section.