Drug · FAERS side-effect profile with label screen
Ampicillin Injection side effects: what 7,402 FDA adverse event reports show
Drug class
Not stated in label
Who reports
7,402 reports · 90% serious · 1,198 with death outcome · 56% 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
Labeled adverse reaction 3Labeled (related wording) 4Likely indication confounding 1Reporting / coding artifact 5Lab value / disease marker 1Not in label — unassessed 26
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- 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.
- 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. 464 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 |
|---|---|---|---|---|---|---|
| Premature delivery | 330 | 59.7 53.6–66.4ROR 62.4 · χ² 18,591 / p <1e-300 | 58.2 EB05 53.2 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious PRR 37.6 · ♀ 100% (drug 56%) · 90% clinician | no trial data cached |
| Premature baby | 499 | 47.6 43.7–51.8ROR 51.0 · χ² 22,368 / p <1e-300 | 46.7 EB05 43.4 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 30.2 · 98% clinician | no trial data cached |
| Foetal exposure during pregnancy | 637 | 22.4 20.8–24.1ROR 24.4 · χ² 12,936 / p <1e-300 | 22.2 EB05 20.8 · IC025 +4.3 3/3 methods agree | Reporting / coding artifact | serious PRR 14.4 · 94% clinician | no trial data cached |
| Maternal exposure during pregnancy | 516 | 16.7 15.3–18.1ROR 17.8 · χ² 7,569 / p <1e-300 | 16.6 EB05 15.4 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 12.5 · ♀ 97% (drug 56%) · 93% clinician | no trial data cached |
| Candida infection (yeast infection) | 96 | 16.4 13.4–20.0ROR 16.6 · χ² 1,365 / p 5e-299 | 16.2 EB05 13.7 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 14.9 · 92% clinician | no trial data cached |
| Clostridium difficile colitis | 61 | 16.4 12.7–21.0ROR 16.5 · χ² 860 / p 3e-189 | 16.2 EB05 13.0 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.6 · 97% clinician | no trial data cached |
| End stage renal disease | 100 | 15.5 12.7–18.8ROR 15.7 · χ² 1,332 / p 7e-292 | 15.3 EB05 12.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | no trial data cached |
| Tubulointerstitial nephritis | 99 | 15.0 12.4–18.3ROR 15.2 · χ² 1,279 / p 3e-280 | 14.9 EB05 12.6 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 | no trial data cached |
| Rash maculo-papular | 105 | 13.5 11.1–16.3ROR 13.7 · χ² 1,197 / p 2e-262 | 13.3 EB05 11.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 · 96% clinician | no trial data cached |
| Leukocytosis | 83 | 13.1 10.5–16.2ROR 13.2 · χ² 909 / p 6e-200 | 12.9 EB05 10.7 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.5 | no trial data cached |
| Toxic epidermal necrolysis (severe skin peeling reaction) | 67 | 12.6 10.0–16.0ROR 12.7 · χ² 704 / p 2e-155 | 12.4 EB05 10.0 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.0 · 96% clinician | no trial data cached |
| Hypotonia | 43 | 12.2 9.0–16.4ROR 12.3 · χ² 429 / p 1e-95 | 11.8 EB05 9.0 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.9 · 93% clinician | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 109 | 12.1 10.1–14.6ROR 12.3 · χ² 1,099 / p 3e-241 | 12.0 EB05 10.2 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.7 · 98% clinician | no trial data cached |
| Bacteraemia | 47 | 11.4 8.5–15.1ROR 11.4 · χ² 432 / p 3e-96 | 11.0 EB05 8.4 · IC025 +2.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 7.3 | no trial data cached |
| Atelectasis | 38 | 11.1 8.1–15.3ROR 11.2 · χ² 339 / p 4e-76 | 10.6 EB05 7.9 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 | no trial data cached |
| Multiple organ dysfunction syndrome | 107 | 10.9 9.0–13.2ROR 11.0 · χ² 950 / p 7e-209 | 10.7 EB05 9.1 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.9 · 98% clinician | no trial data cached |
| Drug resistance | 98 | 10.8 8.9–13.2ROR 11.0 · χ² 864 / p 4e-190 | 10.6 EB05 8.9 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious PRR 7.7 · ♀ 30% (drug 56%) · 97% clinician | no trial data cached |
| Chronic kidney disease | 285 | 10.6 9.4–11.8ROR 11.0 · χ² 2,459 / p <1e-300 | 10.5 EB05 9.5 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 | no trial data cached |
| Septic shock | 151 | 9.9 8.5–11.6ROR 10.1 · χ² 1,202 / p 1e-263 | 9.8 EB05 8.5 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · 94% clinician | no trial data cached |
| Caesarean section | 41 | 9.9 7.3–13.4ROR 10.0 · χ² 318 / p 2e-71 | 9.4 EB05 7.1 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · ♀ 100% (drug 56%) · 94% clinician | no trial data cached |
| Tenderness | 33 | 9.0 6.4–12.6ROR 9.0 · χ² 225 / p 3e-51 | 8.3 EB05 6.1 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=31 · ♀ 77% (drug 56%) | no trial data cached |
| Ventricular extrasystoles | 31 | 8.5 6.0–12.0ROR 8.5 · χ² 196 / p 7e-45 | 7.8 EB05 5.6 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 6.0 | no trial data cached |
| Metabolic acidosis | 94 | 8.4 6.9–10.3ROR 8.5 · χ² 608 / p 2e-134 | 8.2 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 · 92% clinician | no trial data cached |
| Exposure during pregnancy | 181 | 8.3 7.2–9.5ROR 8.4 · χ² 1,149 / p 4e-252 | 8.1 EB05 7.2 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 6.7 · ♀ 100% (drug 56%) | no trial data cached |
| Generalised oedema | 34 | 7.8 5.6–11.0ROR 7.9 · χ² 196 / p 9e-45 | 7.2 EB05 5.4 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.4 | no trial data cached |
| Eye inflammation | 26 | 7.8 5.3–11.5ROR 7.9 · χ² 148 / p 3e-34 | 7.1 EB05 5.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 100% (drug 56%) · 100% clinician | no trial data cached |
| Cardiomegaly | 34 | 7.8 5.6–10.9ROR 7.8 · χ² 194 / p 2e-44 | 7.2 EB05 5.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 | no trial data cached |
| Hyperbilirubinaemia | 28 | 7.7 5.3–11.2ROR 7.7 · χ² 157 / p 3e-36 | 7.0 EB05 5.0 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 · ♀ 35% (drug 56%) · 100% clinician | no trial data cached |
| Disseminated intravascular coagulation | 38 | 7.6 5.6–10.5ROR 7.7 · χ² 212 / p 2e-48 | 7.1 EB05 5.4 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Encephalopathy | 64 | 7.4 5.8–9.5ROR 7.5 · χ² 348 / p 4e-78 | 7.1 EB05 5.7 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Hypothermia | 26 | 7.3 5.0–10.7ROR 7.3 · χ² 134 / p 2e-31 | 6.6 EB05 4.7 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 · ♀ 30% (drug 56%) · 91% clinician | no trial data cached |
| Mitral valve incompetence | 29 | 7.3 5.1–10.5ROR 7.3 · χ² 150 / p 7e-35 | 6.6 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Sars-cov-2 test positive | 34 | 7.2 5.2–10.1ROR 7.3 · χ² 176 / p 2e-40 | 6.7 EB05 5.0 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious n=34 · ♀ 100% (drug 56%) | no trial data cached |
| Eosinophilia | 44 | 7.1 5.3–9.6ROR 7.2 · χ² 226 / p 2e-51 | 6.7 EB05 5.2 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.8 · ♀ 35% (drug 56%) · 100% clinician | no trial data cached |
| Respiratory distress | 69 | 7.1 5.6–9.0ROR 7.2 · χ² 355 / p 2e-79 | 6.8 EB05 5.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · ♀ 34% (drug 56%) · 91% clinician | no trial data cached |
| Acute respiratory distress syndrome | 44 | 7.1 5.3–9.5ROR 7.1 · χ² 222 / p 1e-50 | 6.6 EB05 5.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 92% clinician | no trial data cached |
| Economic problem | 38 | 7.0 5.1–9.6ROR 7.0 · χ² 189 / p 2e-43 | 6.5 EB05 4.9 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 4.7 | no trial data cached |
| Drug eruption | 43 | 6.9 5.1–9.3ROR 7.0 · χ² 212 / p 3e-48 | 6.5 EB05 5.0 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.6 · 92% clinician | no trial data cached |
| Ventricular fibrillation | 26 | 6.6 4.5–9.7ROR 6.6 · χ² 118 / p 7e-28 | 6.0 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.2 | no trial data cached |
| Osteopenia | 35 | 6.5 4.7–9.1ROR 6.5 · χ² 158 / p 2e-36 | 6.0 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | 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) | 824 | 1.8 1.7–1.9ROR 1.9 · χ² 296 / p 2e-66 | 1.8 EB05 1.7 · IC025 +0.7 | Reporting / coding artifact | serious PRR 3.0 · 91% clinician | no trial data cached |
| Foetal exposure during pregnancy | 637 | 22.4 20.8–24.1ROR 24.4 · χ² 12,936 / p <1e-300 | 22.2 EB05 20.8 · IC025 +4.3 3/3 methods agree | Reporting / coding artifact | serious PRR 14.4 · 94% clinician | no trial data cached |
| Maternal exposure during pregnancy | 516 | 16.7 15.3–18.1ROR 17.8 · χ² 7,569 / p <1e-300 | 16.6 EB05 15.4 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 12.5 · ♀ 97% (drug 56%) · 93% clinician | no trial data cached |
| Premature baby | 499 | 47.6 43.7–51.8ROR 51.0 · χ² 22,368 / p <1e-300 | 46.7 EB05 43.4 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 30.2 · 98% clinician | no trial data cached |
| Off label use (used outside approved label) | 429 | 1.4 1.3–1.5ROR 1.4 · χ² 51 / p 5e-13 | 1.4 EB05 1.3 · IC025 +0.3 | Reporting / coding artifact | serious PRR 1.5 | no trial data cached |
| Pyrexia (fever) | 346 | 2.8 2.6–3.1ROR 2.9 · χ² 415 / p 2e-92 | 2.8 EB05 2.6 · IC025 +1.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.2 | no trial data cached |
| Premature delivery | 330 | 59.7 53.6–66.4ROR 62.4 · χ² 18,591 / p <1e-300 | 58.2 EB05 53.2 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious PRR 37.6 · ♀ 100% (drug 56%) · 90% clinician | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 312 | 5.8 5.2–6.5ROR 6.0 · χ² 1,245 / p 5e-273 | 5.8 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Renal failure (kidney failure) | 302 | 6.4 5.7–7.2ROR 6.6 · χ² 1,378 / p <1e-300 | 6.3 EB05 5.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Drug hypersensitivity | 291 | 4.2 3.8–4.8ROR 4.4 · χ² 725 / p 4e-160 | 4.2 EB05 3.8 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.7 · ♀ 82% (drug 56%) | no trial data cached |
| Chronic kidney disease | 285 | 10.6 9.4–11.8ROR 11.0 · χ² 2,459 / p <1e-300 | 10.5 EB05 9.5 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 | no trial data cached |
| Product use in unapproved indication | 275 | 3.2 2.8–3.6ROR 3.3 · χ² 416 / p 9e-93 | 3.2 EB05 2.9 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · ♀ 79% (drug 56%) | no trial data cached |
| Condition aggravated | 238 | 2.2 2.0–2.5ROR 2.3 · χ² 163 / p 1e-37 | 2.2 EB05 2.0 · IC025 +0.9 | Reporting / coding artifact | serious PRR 2.1 · 95% clinician | no trial data cached |
| Rash | 221 | 1.4 1.3–1.6ROR 1.5 · χ² 30 / p 2e-8 | 1.4 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.7 | no trial data cached |
| Pneumonia (lung infection) | 220 | 1.9 1.7–2.2ROR 2.0 · χ² 99 / p 1e-23 | 1.9 EB05 1.7 · IC025 +0.7 | Likely indication confounding term in indications | serious PRR 1.3 | 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.
- Premature delivery — n=330, PRR 59.7
- Premature baby — n=499, PRR 47.6
- Candida infection — n=96, PRR 16.4
- End stage renal disease — n=100, PRR 15.5
- Tubulointerstitial nephritis — n=99, PRR 15.0
- Rash maculo-papular — n=105, PRR 13.5
- Leukocytosis — n=83, PRR 13.1
- Hypotonia — n=43, PRR 12.2
- Atelectasis — n=38, PRR 11.1
- Chronic kidney disease — n=285, PRR 10.6
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 premature baby, pyrexia, premature delivery, acute kidney injury, renal failure, drug hypersensitivity. 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, 504 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.