Misoprostol side effects: what 9,682 FDA adverse event reports show
Drug class
Prostaglandin E1 Analog
Who reports
9,682 reports · 69% serious · 741 with death outcome · 85% female
Used for
Misoprostol is indicated for reducing the risk of NSAID (nonsteroidal anti-inflammatory drugs, including aspirin)–induced gastric ulcers in patients at high risk of complications from gastric ulcer, e.g., the elderly and patients with concomitant debilitating disease, as well as patients at high risk of developing gastric ulceration, such as patients with a history of ulcer.
What it is
DESCRIPTION Misoprostol oral tablets contain either 100 mcg or 200 mcg of misoprostol, a synthetic prostaglandin E1 analog. Misoprostol contains approximately equal amounts of the two diastereomers presented below with their enantiomers indicated by (±): Misoprostol is a water-soluble, viscous liquid.
Boxed warning
MISOPROSTOL ADMINISTRATION TO WOMEN WHO ARE PREGNANT CAN CAUSE BIRTH DEFECTS, ABORTION, PREMATURE BIRTH OR UTERINE RUPTURE. UTERINE RUPTURE HAS BEEN REPORTED WHEN MISOPROSTOL TABLETS WERE ADMINISTERED IN PREGNANT WOMEN TO INDUCE LABOR OR TO INDUCE ABORTION.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,011 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Uterine tachysystole | 104 | 5,697.2 3,945.2–8,227.3ROR 5,759.1 · χ² 159,987 / p <1e-300 | 1,206.2 EB05 1,023.9 · IC025 +7.2 3/3 methods agree | Not in label — unassessed | serious n=102 · 92% consumer | no trial data cached |
| Abortion induced incomplete | 23 | 4,094.9 2,038.2–8,227.0ROR 4,104.6 · χ² 30,886 / p <1e-300 | 645.4 EB05 452.9 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=22 | no trial data cached |
| Post abortion infection | 15 | 3,560.8 1,558.6–8,134.7ROR 3,566.3 · χ² 18,705 / p <1e-300 | 492.6 EB05 316.9 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious n=13 | no trial data cached |
| Abortion incomplete | 1,159 | 3,517.3 3,209.7–3,854.3ROR 3,995.5 · χ² 1,538,383 / p <1e-300 | 1,300.9 EB05 1,239.2 · IC025 +9.6 3/3 methods agree | Not in label — unassessed | serious n=293 · 98% clinician | no trial data cached |
| Induced abortion failed | 73 | 2,689.0 1,905.9–3,793.7ROR 2,709.4 · χ² 85,659 / p <1e-300 | 905.9 EB05 744.5 · IC025 +6.6 3/3 methods agree | Not in label — unassessed | serious n=68 · 95% clinician | no trial data cached |
| Foetal exposure during delivery | 207 | 943.0 801.7–1,109.2ROR 963.5 · χ² 134,486 / p <1e-300 | 616.9 EB05 549.6 · IC025 +7.8 3/3 methods agree | Reporting / coding artifact | serious n=206 · ♀ 37% (drug 85%) · 93% consumer | no trial data cached |
| Foetal methotrexate syndrome | 20 | 821.7 490.8–1,375.7ROR 823.4 · χ² 11,255 / p <1e-300 | 378.3 EB05 258.6 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | no trial data cached |
| Birth trauma | 16 | 697.6 396.9–1,226.2ROR 698.8 · χ² 7,873 / p <1e-300 | 322.9 EB05 210.7 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Endometritis | 157 | 669.5 560.3–800.1ROR 680.5 · χ² 79,288 / p <1e-300 | 480.0 EB05 420.2 · IC025 +7.3 3/3 methods agree | Not in label — unassessed | serious n=106 · 98% clinician | no trial data cached |
| Traumatic delivery | 12 | 657.4 344.3–1,255.1ROR 658.2 · χ² 5,522 / p <1e-300 | 279.3 EB05 170.3 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Precipitate labour | 15 | 628.4 353.5–1,117.1ROR 629.3 · χ² 6,783 / p <1e-300 | 300.0 EB05 193.0 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Post abortion haemorrhage | 30 | 567.2 379.4–847.9ROR 569.0 · χ² 12,955 / p <1e-300 | 348.6 EB05 255.9 · IC025 +5.1 3/3 methods agree | Labeled (related wording) related wording | serious n=30 · 90% clinician | no trial data cached |
| Truncus arteriosus persistent | 41 | 554.4 393.4–781.2ROR 556.7 · χ² 17,545 / p <1e-300 | 365.2 EB05 280.6 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=41 · 92% clinician | no trial data cached |
| Retained products of conception | 40 | 521.1 369.0–735.8ROR 523.2 · χ² 16,277 / p <1e-300 | 349.0 EB05 267.3 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=34 | no trial data cached |
| Vascular resistance systemic increased | 10 | 521.1 261.1–1,039.9ROR 521.6 · χ² 3,765 / p <1e-300 | 233.1 EB05 135.3 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Anaphylactoid syndrome of pregnancy | 16 | 427.3 249.9–730.6ROR 428.0 · χ² 5,321 / p <1e-300 | 250.0 EB05 163.2 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Foetal heart rate decreased | 100 | 411.6 332.6–509.4ROR 415.9 · χ² 34,005 / p <1e-300 | 323.9 EB05 274.0 · IC025 +6.7 3/3 methods agree | Lab value / disease marker | serious n=100 · ♀ 44% (drug 85%) · 93% consumer | no trial data cached |
| Abnormal labour | 19 | 372.4 228.9–606.0ROR 373.1 · χ² 5,681 / p <1e-300 | 240.7 EB05 162.8 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Uterine cervical laceration | 11 | 297.5 158.4–558.8ROR 297.8 · χ² 2,599 / p <1e-300 | 180.2 EB05 107.3 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=11 | no trial data cached |
| Uterine atony | 31 | 297.0 204.1–432.2ROR 297.9 · χ² 7,771 / p <1e-300 | 224.8 EB05 165.9 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=30 | no trial data cached |
| Labour pain | 11 | 293.8 156.5–551.6ROR 294.1 · χ² 2,570 / p <1e-300 | 178.8 EB05 106.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Perineal injury | 18 | 291.3 178.1–476.5ROR 291.9 · χ² 4,331 / p <1e-300 | 201.8 EB05 135.1 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Uterine hyperstimulation | 11 | 264.1 141.2–493.9ROR 264.4 · χ² 2,337 / p <1e-300 | 167.4 EB05 99.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Amniocentesis abnormal | 17 | 259.4 156.9–429.0ROR 259.9 · χ² 3,675 / p <1e-300 | 183.9 EB05 121.6 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Foetal heart rate disorder | 19 | 243.1 151.3–390.5ROR 243.5 · χ² 3,898 / p <1e-300 | 179.3 EB05 121.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Neonatal respiratory arrest | 14 | 224.9 129.7–389.9ROR 225.2 · χ² 2,624 / p <1e-300 | 159.7 EB05 101.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Kidney duplex | 22 | 221.7 143.0–343.8ROR 222.2 · χ² 4,181 / p <1e-300 | 171.3 EB05 119.3 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=22 | no trial data cached |
| Congenital multiplex arthrogryposis | 18 | 206.8 127.5–335.3ROR 207.1 · χ² 3,175 / p <1e-300 | 157.4 EB05 105.4 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Retained placenta or membranes | 25 | 197.8 131.4–297.9ROR 198.3 · χ² 4,302 / p <1e-300 | 159.3 EB05 113.5 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=25 | no trial data cached |
| Uterine hypertonus | 22 | 189.5 122.6–293.0ROR 190.0 · χ² 3,618 / p <1e-300 | 151.5 EB05 105.5 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=21 | no trial data cached |
| Uterine rupture | 112 | 183.9 151.8–222.8ROR 186.1 · χ² 18,594 / p <1e-300 | 164.7 EB05 140.7 · IC025 +6.3 3/3 methods agree | Labeled — boxed warning exact term | serious n=113 | no trial data cached |
| Adactyly | 12 | 176.8 98.2–318.5ROR 177.0 · χ² 1,778 / p <1e-300 | 130.1 EB05 79.3 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Infantile haemangioma | 12 | 173.2 96.2–311.9ROR 173.4 · χ² 1,745 / p <1e-300 | 128.2 EB05 78.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Abnormal palmar/plantar creases | 14 | 162.6 94.4–279.8ROR 162.8 · χ² 1,941 / p <1e-300 | 125.7 EB05 79.6 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Meconium in amniotic fluid | 23 | 153.1 100.3–233.6ROR 153.4 · χ² 3,102 / p <1e-300 | 128.0 EB05 89.8 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=23 · 90% clinician | no trial data cached |
| Micrognathia | 33 | 151.6 106.6–215.7ROR 152.1 · χ² 4,471 / p <1e-300 | 131.1 EB05 97.7 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=33 · ♀ 33% (drug 85%) | no trial data cached |
| Bloody discharge | 73 | 146.7 115.8–185.8ROR 147.8 · χ² 9,751 / p <1e-300 | 132.7 EB05 109.0 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=73 · 95% clinician | no trial data cached |
| Congenital megaureter | 12 | 142.4 79.4–255.4ROR 142.6 · χ² 1,450 / p <1e-300 | 110.6 EB05 67.4 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Clinodactyly | 17 | 141.3 86.5–230.8ROR 141.6 · χ² 2,092 / p <1e-300 | 115.7 EB05 76.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| External auditory canal atresia | 10 | 140.6 74.1–266.4ROR 140.7 · χ² 1,172 / p 3e-257 | 105.9 EB05 61.5 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Haemorrhage | 1,260 | 26.4 25.1–27.8ROR 30.2 · χ² 30,561 / p <1e-300 | 26.1 EB05 24.9 · IC025 +4.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 11.1 · 92% clinician | no trial data cached |
| Abortion incomplete | 1,159 | 3,517.3 3,209.7–3,854.3ROR 3,995.5 · χ² 1,538,383 / p <1e-300 | 1,300.9 EB05 1,239.2 · IC025 +9.6 3/3 methods agree | Not in label — unassessed | serious n=293 · 98% clinician | no trial data cached |
| Off label use (used outside approved label) | 916 | 2.3 2.2–2.4ROR 2.4 · χ² 690 / p 2e-152 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 3.0 | no trial data cached |
| Foetal exposure during pregnancy | 632 | 17.0 15.7–18.3ROR 18.1 · χ² 9,447 / p <1e-300 | 16.8 EB05 15.8 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 14.3 · ♀ 49% (drug 85%) | no trial data cached |
| Pain | 540 | 1.9 1.8–2.1ROR 2.0 · χ² 237 / p 1e-53 | 1.9 EB05 1.8 · IC025 +0.8 | Labeled — boxed warning exact term | serious PRR 1.7 | no trial data cached |
| Anaemia (low red blood cells) | 511 | 5.8 5.3–6.3ROR 6.1 · χ² 2,044 / p <1e-300 | 5.8 EB05 5.4 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.3 · 92% clinician | no trial data cached |
| Pregnancy | 449 | 49.2 44.9–53.9ROR 51.5 · χ² 20,679 / p <1e-300 | 48.0 EB05 44.4 · IC025 +5.4 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 5.6 · 98% clinician | no trial data cached |
| Nausea | 445 | 1.2 1.1–1.3ROR 1.2 · χ² 18 / p 9e-6 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.5 | no trial data cached |
| Drug ineffective (drug did not work) | 436 | 0.7 0.7–0.8ROR 0.7 · χ² 52 / p 3e-13 | 0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.4 | no trial data cached |
| Vomiting | 426 | 2.0 1.8–2.2ROR 2.0 · χ² 207 / p 4e-47 | 2.0 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 1.9 | no trial data cached |
| Maternal exposure during pregnancy | 410 | 10.1 9.2–11.1ROR 10.5 · χ² 3,355 / p <1e-300 | 10.0 EB05 9.2 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 9.3 | no trial data cached |
| Pyrexia (fever) | 406 | 2.5 2.3–2.8ROR 2.6 · χ² 384 / p 8e-86 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.2 | no trial data cached |
| Dizziness | 396 | 1.7 1.6–1.9ROR 1.8 · χ² 122 / p 1e-28 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.7 | no trial data cached |
| Muscle spasms | 352 | 4.2 3.8–4.6ROR 4.3 · χ² 848 / p 1e-186 | 4.1 EB05 3.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | no trial data cached |
| Abdominal pain | 348 | 3.2 2.9–3.6ROR 3.3 · χ² 544 / p 1e-120 | 3.2 EB05 3.0 · IC025 +1.5 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 2.6 | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Uterine tachysystole — n=104, PRR 5,697.2
- Abortion induced incomplete — n=23, PRR 4,094.9
- Abortion incomplete — n=1,159, PRR 3,517.3
- Induced abortion failed — n=73, PRR 2,689.0
- Foetal methotrexate syndrome — n=20, PRR 821.7
- Endometritis — n=157, PRR 669.5
- Truncus arteriosus persistent — n=41, PRR 554.4
- Retained products of conception — n=40, PRR 521.1
- Uterine atony — n=31, PRR 297.0
- Kidney duplex — n=22, PRR 221.7
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Misoprostol?
In FDA FAERS, the most frequently co-reported reaction terms for Misoprostol are haemorrhage, abortion incomplete, pain, anaemia, pregnancy, nausea. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Misoprostol have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: MISOPROSTOL ADMINISTRATION TO WOMEN WHO ARE PREGNANT CAN CAUSE BIRTH DEFECTS, ABORTION, PREMATURE BIRTH OR UTERINE RUPTURE. UTERINE RUPTURE HAS BEEN REPORTED WHEN MISOPROSTOL TABLETS WERE ADMINISTERED IN PREGNANT WOMEN TO INDUCE LABOR OR TO INDUCE ABORTION.
Do FAERS signals prove that Misoprostol causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 14f73ae3-7d8d-4d10-b668-8bd5adf8032c, effective 20201221; matched on
openfda.generic_name.exact:"MISOPROSTOL") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,051 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.