Drug · FAERS side-effect profile with label screen
Ampicillin side effects: what 8,234 FDA adverse event reports show
Drug class
Not stated in label
Who reports
8,234 reports · 87% serious · 1,308 with death outcome · 57% female
openFDA FAERS counts, all years, deduplication not applied
Used for
To reduce the development of drug-resistant bacteria and maintain the effectiveness of ampicillin capsules, ampicillin for oral suspension and other antibacterial drugs, ampicillin capsules and ampicillin for oral suspension should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.
FDA label, Indications and Usage
What it is
DESCRIPTION Ampicillin trihydrate is a semisynthetic penicillin derived from the basic penicillin nucleus, 6- aminopenicillanic acid. Ampicillin is designated chemically as (2S, 5 R , 6 R )-6-[( R )-2-Amino-2-phenylacetamido]-3,3- dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0] heptane-2- carboxylic acid.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Likely indication confounding 3Not in label — unassessed 37
What the badges mean
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- 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. 1,050 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Normal labour | 122 | 18,027.9 10,858.7–29,930.2ROR 18,299.0 · χ² 266,762 / p <1e-300 | 1,634.4 EB05 1,405.1 · IC025 +7.5 3/3 methods agree | Not in label — unassessed | serious n=122 · ♀ 100% (drug 57%) | no trial data cached |
| Neonatal candida infection | 18 | 1,808.7 987.2–3,313.8ROR 1,812.7 · χ² 17,871 / p <1e-300 | 495.4 EB05 331.5 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Umbilical erythema | 14 | 764.5 420.5–1,390.1ROR 765.8 · χ² 7,610 / p <1e-300 | 325.4 EB05 206.0 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Meningitis candida | 13 | 604.8 330.2–1,107.6ROR 605.7 · χ² 5,838 / p <1e-300 | 284.0 EB05 176.6 · IC025 +3.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=13 | no trial data cached |
| Delivery | 126 | 599.5 494.2–727.2ROR 608.8 · χ² 60,298 / p <1e-300 | 450.9 EB05 388.6 · IC025 +7.1 3/3 methods agree | Not in label — unassessed | serious n=126 · ♀ 100% (drug 57%) | no trial data cached |
| Acquired factor v deficiency | 13 | 336.7 188.8–600.4ROR 337.2 · χ² 3,546 / p <1e-300 | 207.1 EB05 128.8 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Congenital cystic lung | 13 | 305.2 171.7–542.5ROR 305.7 · χ² 3,249 / p <1e-300 | 194.8 EB05 121.1 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Congenital multiplex arthrogryposis | 19 | 258.0 161.0–413.5ROR 258.6 · χ² 4,181 / p <1e-300 | 189.7 EB05 128.4 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Encephalitis brain stem | 13 | 213.4 121.2–375.9ROR 213.8 · χ² 2,341 / p <1e-300 | 153.1 EB05 95.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Kidney duplex | 18 | 209.3 129.5–338.4ROR 209.8 · χ² 3,255 / p <1e-300 | 160.7 EB05 107.5 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Intraventricular haemorrhage neonatal | 37 | 208.9 149.5–291.9ROR 209.8 · χ² 6,876 / p <1e-300 | 175.6 EB05 133.0 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=37 · 100% clinician | no trial data cached |
| Therapeutic product cross-reactivity | 61 | 184.2 142.1–238.6ROR 185.5 · χ² 10,185 / p <1e-300 | 163.0 EB05 131.5 · IC025 +5.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=61 · ♀ 90% (drug 57%) · 100% clinician | no trial data cached |
| Sepsis neonatal | 50 | 168.8 126.9–224.6ROR 169.8 · χ² 7,660 / p <1e-300 | 149.3 EB05 117.7 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=50 · 100% clinician | no trial data cached |
| Conductive deafness | 18 | 150.2 93.4–241.6ROR 150.6 · χ² 2,379 / p <1e-300 | 123.5 EB05 82.7 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Amniotic cavity infection | 40 | 149.3 108.6–205.3ROR 150.0 · χ² 5,423 / p <1e-300 | 132.2 EB05 101.3 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 100% (drug 57%) | no trial data cached |
| Thymus disorder | 10 | 139.6 73.9–263.7ROR 139.7 · χ² 1,175 / p 7e-258 | 106.1 EB05 61.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Vitamin k deficiency | 20 | 134.7 85.9–211.1ROR 135.0 · χ² 2,394 / p <1e-300 | 114.2 EB05 78.1 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | no trial data cached |
| Neonatal respiratory failure | 24 | 126.1 83.8–189.9ROR 126.5 · χ² 2,719 / p <1e-300 | 109.9 EB05 77.7 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=24 · 91% clinician | no trial data cached |
| Monocytosis | 28 | 120.6 82.6–176.2ROR 121.1 · χ² 3,057 / p <1e-300 | 106.9 EB05 77.7 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 100% (drug 57%) · 100% clinician | no trial data cached |
| Necrotising enterocolitis neonatal | 17 | 112.4 69.2–182.6ROR 112.6 · χ² 1,691 / p <1e-300 | 96.3 EB05 63.7 · IC025 +3.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=17 | no trial data cached |
| Listeriosis | 45 | 108.5 80.6–146.1ROR 109.1 · χ² 4,492 / p <1e-300 | 99.7 EB05 77.6 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=45 · 100% clinician | no trial data cached |
| Thrombocytopenia neonatal | 17 | 108.4 66.7–176.0ROR 108.6 · χ² 1,633 / p <1e-300 | 93.3 EB05 61.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Pleocytosis | 22 | 100.5 65.7–153.8ROR 100.7 · χ² 1,989 / p <1e-300 | 89.4 EB05 62.2 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=22 · 90% clinician | no trial data cached |
| Hydrops foetalis | 23 | 99.4 65.6–150.8ROR 99.7 · χ² 2,062 / p <1e-300 | 88.8 EB05 62.4 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=23 · 91% clinician | no trial data cached |
| Neonatal infection | 13 | 99.3 57.1–172.7ROR 99.4 · χ² 1,124 / p 1e-246 | 84.1 EB05 52.3 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Type iv hypersensitivity reaction | 100 | 97.1 79.6–118.4ROR 98.2 · χ² 9,063 / p <1e-300 | 91.9 EB05 77.7 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=100 · 100% clinician | no trial data cached |
| Hepatic infarction | 12 | 83.5 47.0–148.4ROR 83.6 · χ² 869 / p 3e-191 | 72.0 EB05 43.9 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Neonatal disorder | 48 | 79.0 59.3–105.2ROR 79.5 · χ² 3,510 / p <1e-300 | 74.5 EB05 58.4 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=47 · ♀ 36% (drug 57%) · 100% clinician | no trial data cached |
| Jarisch-herxheimer reaction | 21 | 77.1 50.0–119.0ROR 77.3 · χ² 1,458 / p <1e-300 | 70.3 EB05 48.5 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=21 | no trial data cached |
| Laryngeal stenosis | 16 | 72.6 44.2–119.2ROR 72.7 · χ² 1,029 / p 5e-226 | 65.3 EB05 42.6 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Neonatal hypotension | 10 | 71.4 38.1–133.8ROR 71.5 · χ² 608 / p 2e-134 | 61.7 EB05 35.8 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Bradycardia neonatal | 34 | 71.1 50.6–99.9ROR 71.4 · χ² 2,218 / p <1e-300 | 66.7 EB05 49.9 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=34 | no trial data cached |
| Anaemia neonatal | 13 | 70.2 40.5–121.8ROR 70.3 · χ² 797 / p 1e-175 | 62.4 EB05 38.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Glomerulonephritis membranoproliferative | 14 | 69.6 41.0–118.4ROR 69.8 · χ² 856 / p 2e-188 | 62.3 EB05 39.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Pulmonary artery stenosis | 10 | 65.9 35.2–123.5ROR 66.0 · χ² 561 / p 2e-124 | 57.6 EB05 33.4 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Death neonatal | 34 | 64.4 45.9–90.5ROR 64.7 · χ² 2,008 / p <1e-300 | 60.8 EB05 45.5 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=34 · 94% clinician | no trial data cached |
| Polyhydramnios | 25 | 64.0 43.1–95.2ROR 64.2 · χ² 1,452 / p <1e-300 | 59.7 EB05 42.6 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=25 | no trial data cached |
| Neonatal hypoxia | 20 | 63.1 40.5–98.3ROR 63.3 · χ² 1,133 / p 1e-248 | 58.3 EB05 39.9 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=20 | no trial data cached |
| Cerebral palsy | 23 | 62.7 41.5–94.7ROR 62.8 · χ² 1,302 / p 2e-285 | 58.4 EB05 41.0 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=23 | no trial data cached |
| Bronchopulmonary dysplasia | 19 | 61.7 39.2–97.3ROR 61.9 · χ² 1,050 / p 1e-230 | 57.0 EB05 38.6 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 860 | 1.7 1.6–1.8ROR 1.7 · χ² 242 / p 7e-55 | 1.7 EB05 1.6 · IC025 +0.6 | Reporting / coding artifact | serious PRR 2.9 · 91% clinician | no trial data cached |
| Foetal exposure during pregnancy | 657 | 20.8 19.3–22.3ROR 22.5 · χ² 12,281 / p <1e-300 | 20.6 EB05 19.3 · IC025 +4.2 3/3 methods agree | Reporting / coding artifact | serious PRR 13.8 · 94% clinician | no trial data cached |
| Drug hypersensitivity | 605 | 8.0 7.4–8.6ROR 8.5 · χ² 3,695 / p <1e-300 | 7.9 EB05 7.4 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.0 · ♀ 81% (drug 57%) | no trial data cached |
| Maternal exposure during pregnancy | 535 | 15.5 14.3–16.9ROR 16.5 · χ² 7,247 / p <1e-300 | 15.4 EB05 14.4 · IC025 +3.8 3/3 methods agree | Reporting / coding artifact | serious PRR 12.1 · ♀ 97% (drug 57%) · 93% clinician | no trial data cached |
| Premature baby | 511 | 43.8 40.3–47.7ROR 46.7 · χ² 21,009 / p <1e-300 | 43.0 EB05 40.0 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 28.8 · 97% clinician | no trial data cached |
| Off label use (used outside approved label) | 435 | 1.3 1.2–1.4ROR 1.3 · χ² 27 / p 1e-7 | 1.3 EB05 1.2 · IC025 +0.2 | Reporting / coding artifact | serious PRR 1.4 | no trial data cached |
| Pyrexia (fever) | 375 | 2.8 2.5–3.0ROR 2.8 · χ² 426 / p 7e-95 | 2.8 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.2 | no trial data cached |
| Premature delivery | 337 | 54.8 49.3–60.9ROR 57.1 · χ² 17,376 / p <1e-300 | 53.5 EB05 48.9 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious PRR 35.8 · ♀ 100% (drug 57%) · 91% clinician | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 329 | 5.5 5.0–6.1ROR 5.7 · χ² 1,216 / p 8e-267 | 5.5 EB05 5.0 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.6 | no trial data cached |
| Renal failure (kidney failure) | 316 | 6.0 5.4–6.7ROR 6.2 · χ² 1,325 / p 2e-290 | 6.0 EB05 5.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Chronic kidney disease | 285 | 9.5 8.5–10.7ROR 9.8 · χ² 2,159 / p <1e-300 | 9.4 EB05 8.5 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Product use in unapproved indication | 281 | 2.9 2.6–3.3ROR 3.0 · χ² 359 / p 2e-80 | 2.9 EB05 2.6 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 4.0 · ♀ 79% (drug 57%) | no trial data cached |
| Rash | 274 | 1.6 1.4–1.8ROR 1.6 · χ² 64 / p 6e-16 | 1.6 EB05 1.5 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial data cached |
| Pain | 260 | 1.1 1.0–1.2ROR 1.1 · χ² 1 / p 0.121 | 1.1 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 1.1 | no trial data cached |
| Condition aggravated | 253 | 2.1 1.9–2.4ROR 2.2 · χ² 154 / p 1e-35 | 2.1 EB05 1.9 · IC025 +0.9 | Reporting / coding artifact | serious PRR 2.1 · 95% clinician | 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.
- Normal labour — n=122, PRR 18,027.9
- Delivery — n=126, PRR 599.5
- Intraventricular haemorrhage neonatal — n=37, PRR 208.9
- Sepsis neonatal — n=50, PRR 168.8
- Amniotic cavity infection — n=40, PRR 149.3
- Vitamin k deficiency — n=20, PRR 134.7
- Neonatal respiratory failure — n=24, PRR 126.1
- Monocytosis — n=28, PRR 120.6
- Listeriosis — n=45, PRR 108.5
- Pleocytosis — n=22, PRR 100.5
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 Ampicillin?
In FDA FAERS, the most frequently co-reported reaction terms for Ampicillin are drug hypersensitivity, premature baby, pyrexia, premature delivery, acute kidney injury, renal failure. 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 Ampicillin have an FDA boxed warning?
No. The FDA label retrieved for Ampicillin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Ampicillin 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 0a66c5c3-63bf-46e3-835e-26b555ab6954, effective 20250717; matched on
openfda.generic_name.exact:"AMPICILLIN") - 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, 1,090 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.