Drug · FAERS side-effect profile with label screen
Penicillin G side effects: what 2,306 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Penicillin G Potassium
openFDA label
Who reports
2,306 reports · 74% serious · 231 with death outcome · 57% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Therapy Penicillin G Potassium Injection, USP is indicated in the treatment of serious infections caused by susceptible strains of the designated microorganisms in the conditions listed below. Appropriate culture and susceptibility tests should be done before treatment in order to isolate and identify organisms causing infection and to determine their susceptibility to penicillin G.
FDA label, Indications and Usage
What it is
DESCRIPTION Penicillin G Potassium, USP is a natural penicillin. It is chemically designated 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino]-, monopotassium salt, [2 S -(2α, 5α, 6β)]. It is crystalline.
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 1Labeled (related wording) 3Likely indication confounding 1Reporting / coding artifact 3Lab value / disease marker 2Not in label — unassessed 30
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. 114 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 |
|---|---|---|---|---|---|---|
| Hepatic steatosis | 107 | 52.6 43.7–63.4ROR 55.1 · χ² 5,342 / p <1e-300 | 51.9 EB05 44.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 46.4 · ♀ 88% (drug 57%) | no trial data cached |
| Contraindicated product administered | 107 | 32.4 26.9–39.0ROR 33.9 · χ² 3,217 / p <1e-300 | 32.1 EB05 27.3 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | serious PRR 31.0 | no trial data cached |
| Sleep disorder due to a general medical condition | 56 | 31.6 24.4–41.0ROR 32.4 · χ² 1,626 / p <1e-300 | 31.2 EB05 24.9 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 48.5 | no trial data cached |
| Drug hypersensitivity | 669 | 31.5 29.5–33.5ROR 43.9 · χ² 19,812 / p <1e-300 | 31.3 EB05 29.4 · IC025 +4.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 27.0 | no trial data cached |
| Arteriosclerosis | 31 | 30.0 21.2–42.6ROR 30.4 · χ² 838 / p 1e-184 | 29.4 EB05 21.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 24.0 · ♀ 4% (drug 57%) | no trial data cached |
| Full blood count abnormal | 34 | 29.4 21.1–41.1ROR 29.9 · χ² 903 / p 9e-199 | 28.9 EB05 21.6 · IC025 +3.8 3/3 methods agree | Lab value / disease marker | serious PRR 30.3 · ♀ 19% (drug 57%) | no trial data cached |
| Sleep apnoea syndrome | 57 | 27.2 21.0–35.2ROR 27.9 · χ² 1,409 / p <1e-300 | 26.9 EB05 21.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 25.1 · ♀ 94% (drug 57%) | no trial data cached |
| Atelectasis | 28 | 26.4 18.2–38.1ROR 26.7 · χ² 656 / p 5e-145 | 25.9 EB05 18.8 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 20.7 · ♀ 8% (drug 57%) · 96% clinician | no trial data cached |
| Obstructive airways disorder | 30 | 24.5 17.2–35.0ROR 24.8 · χ² 652 / p 4e-144 | 24.1 EB05 17.7 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 19.8 · ♀ 0% (drug 57%) | no trial data cached |
| Therapeutic product effect decreased | 114 | 23.4 19.6–28.0ROR 24.6 · χ² 2,425 / p <1e-300 | 23.3 EB05 19.9 · IC025 +4.1 3/3 methods agree | Reporting / coding artifact | serious PRR 35.3 · ♀ 87% (drug 57%) | no trial data cached |
| Vasculitis | 29 | 22.7 15.8–32.6ROR 23.0 · χ² 579 / p 4e-128 | 22.3 EB05 16.3 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 18.9 · ♀ 0% (drug 57%) | no trial data cached |
| Fibromyalgia | 60 | 22.5 17.6–28.9ROR 23.1 · χ² 1,212 / p 9e-266 | 22.3 EB05 18.0 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 23.0 · ♀ 100% (drug 57%) | no trial data cached |
| Nodule | 31 | 21.7 15.3–30.7ROR 21.9 · χ² 589 / p 2e-130 | 21.4 EB05 15.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 26.0 · ♀ 0% (drug 57%) | no trial data cached |
| Motor dysfunction | 22 | 19.8 13.1–30.1ROR 20.0 · χ² 374 / p 1e-83 | 19.4 EB05 13.4 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 19.4 · ♀ 5% (drug 57%) · 100% clinician | no trial data cached |
| Drug intolerance | 192 | 18.2 15.9–20.8ROR 19.8 · χ² 3,110 / p <1e-300 | 18.1 EB05 16.1 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 22.8 · ♀ 79% (drug 57%) · 92% clinician | no trial data cached |
| Brain injury | 20 | 18.2 11.7–28.1ROR 18.3 · χ² 307 / p 5e-69 | 17.7 EB05 11.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 14.3 · 100% clinician | no trial data cached |
| Synovitis | 35 | 17.7 12.7–24.6ROR 17.9 · χ² 534 / p 2e-118 | 17.5 EB05 13.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 14.4 · 100% clinician | no trial data cached |
| Cystitis | 60 | 17.1 13.3–22.0ROR 17.5 · χ² 894 / p 1e-196 | 17.0 EB05 13.6 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 17.8 · ♀ 100% (drug 57%) | no trial data cached |
| Tachypnoea | 24 | 16.1 10.8–24.1ROR 16.3 · χ² 326 / p 4e-73 | 15.8 EB05 10.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 12.9 · ♀ 13% (drug 57%) · 100% clinician | no trial data cached |
| Muscle atrophy | 22 | 15.9 10.5–24.2ROR 16.1 · χ² 293 / p 5e-66 | 15.5 EB05 10.5 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 16.0 · ♀ 5% (drug 57%) · 91% clinician | no trial data cached |
| Pulmonary fibrosis | 32 | 15.3 10.8–21.5ROR 15.5 · χ² 412 / p 7e-92 | 15.0 EB05 10.9 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 12.0 · ♀ 0% (drug 57%) | no trial data cached |
| Sputum discoloured | 15 | 14.5 8.7–24.0ROR 14.6 · χ² 175 / p 4e-40 | 13.5 EB05 8.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 14.7 | no trial data cached |
| Poor venous access | 16 | 14.1 8.7–23.0ROR 14.2 · χ² 182 / p 9e-42 | 13.2 EB05 8.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Circulatory collapse | 26 | 13.9 9.5–20.3ROR 14.0 · χ² 297 / p 7e-67 | 13.4 EB05 9.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 · ♀ 8% (drug 57%) · 92% clinician | no trial data cached |
| Leukocytosis | 27 | 13.6 9.4–19.8ROR 13.8 · χ² 303 / p 4e-68 | 13.1 EB05 9.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 | no trial data cached |
| Anaphylactic reaction (severe allergic reaction) | 81 | 13.4 10.8–16.6ROR 13.9 · χ² 921 / p 1e-202 | 13.3 EB05 11.0 · IC025 +3.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.7 · ♀ 94% (drug 57%) · 90% clinician | no trial data cached |
| Secretion discharge | 18 | 13.3 8.4–21.0ROR 13.4 · χ² 192 / p 6e-44 | 12.4 EB05 7.8 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 16.9 | no trial data cached |
| Caesarean section | 17 | 13.2 8.2–21.2ROR 13.3 · χ² 179 / p 4e-41 | 12.2 EB05 7.5 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 10.5 | no trial data cached |
| Liver disorder | 62 | 12.8 10.0–16.3ROR 13.1 · χ² 660 / p 6e-146 | 12.6 EB05 10.1 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 11.7 · ♀ 96% (drug 57%) | no trial data cached |
| Cardiac failure congestive | 107 | 12.0 10.0–14.5ROR 12.6 · χ² 1,073 / p 1e-235 | 11.9 EB05 10.1 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 9.4 · ♀ 91% (drug 57%) | no trial data cached |
| Musculoskeletal chest pain | 20 | 11.8 7.6–18.2ROR 11.9 · χ² 186 / p 1e-42 | 10.9 EB05 7.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 13.0 | no trial data cached |
| Hypothyroidism | 41 | 11.7 8.7–15.9ROR 11.9 · χ² 392 / p 2e-87 | 11.3 EB05 8.5 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 · ♀ 29% (drug 57%) | no trial data cached |
| Flank pain | 12 | 11.7 6.6–20.6ROR 11.7 · χ² 107 / p 3e-25 | 10.0 EB05 5.5 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 11.9 | no trial data cached |
| Haemoptysis | 35 | 11.4 8.2–15.9ROR 11.6 · χ² 322 / p 3e-72 | 10.9 EB05 8.0 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 · ♀ 15% (drug 57%) | no trial data cached |
| Tinnitus (ringing in the ears) | 57 | 11.3 8.7–14.6ROR 11.5 · χ² 525 / p 2e-116 | 11.0 EB05 8.7 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.5 · ♀ 100% (drug 57%) | no trial data cached |
| Loss of personal independence in daily activities | 58 | 11.1 8.6–14.3ROR 11.4 · χ² 524 / p 3e-116 | 10.8 EB05 8.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.4 | no trial data cached |
| Pain in jaw | 34 | 10.9 7.8–15.3ROR 11.1 · χ² 297 / p 8e-67 | 10.4 EB05 7.6 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 13.8 · ♀ 9% (drug 57%) | no trial data cached |
| Hepatic enzyme increased | 77 | 10.3 8.3–12.9ROR 10.6 · χ² 640 / p 1e-141 | 10.1 EB05 8.3 · IC025 +2.9 3/3 methods agree | Lab value / disease marker | serious PRR 11.5 · ♀ 79% (drug 57%) | no trial data cached |
| Clostridium difficile colitis | 12 | 10.3 5.9–18.1ROR 10.3 · χ² 92 / p 5e-22 | 8.5 EB05 4.8 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.2 | no trial data cached |
| Productive cough (cough with phlegm) | 52 | 10.0 7.6–13.1ROR 10.2 · χ² 413 / p 4e-92 | 9.6 EB05 7.5 · IC025 +2.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 11.3 | 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 hypersensitivity | 669 | 31.5 29.5–33.5ROR 43.9 · χ² 19,812 / p <1e-300 | 31.3 EB05 29.4 · IC025 +4.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 27.0 | no trial data cached |
| Rash | 241 | 5.1 4.5–5.7ROR 5.5 · χ² 797 / p 1e-175 | 5.0 EB05 4.5 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.8 · ♀ 87% (drug 57%) | no trial data cached |
| Malaise (feeling unwell) | 198 | 4.1 3.6–4.7ROR 4.4 · χ² 471 / p 1e-104 | 4.1 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.3 · ♀ 82% (drug 57%) | no trial data cached |
| Drug intolerance | 192 | 18.2 15.9–20.8ROR 19.8 · χ² 3,110 / p <1e-300 | 18.1 EB05 16.1 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | serious PRR 22.8 · ♀ 79% (drug 57%) · 92% clinician | no trial data cached |
| Abdominal pain upper | 180 | 8.0 6.9–9.2ROR 8.6 · χ² 1,102 / p 6e-242 | 7.9 EB05 6.9 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 11.4 · ♀ 91% (drug 57%) | no trial data cached |
| Cough | 161 | 5.2 4.5–6.1ROR 5.6 · χ² 555 / p 5e-123 | 5.2 EB05 4.5 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 · ♀ 86% (drug 57%) | no trial data cached |
| Hypersensitivity (allergic reaction) | 149 | 7.3 6.3–8.6ROR 7.8 · χ² 813 / p 3e-179 | 7.2 EB05 6.3 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.1 · ♀ 84% (drug 57%) | no trial data cached |
| Anxiety | 142 | 4.5 3.9–5.3ROR 4.8 · χ² 392 / p 1e-87 | 4.5 EB05 3.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | no trial data cached |
| Hypertension (high blood pressure) | 142 | 6.1 5.2–7.2ROR 6.4 · χ² 606 / p 4e-134 | 6.0 EB05 5.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 · ♀ 91% (drug 57%) | no trial data cached |
| Urticaria (hives) | 124 | 6.8 5.7–8.1ROR 7.1 · χ² 610 / p 5e-135 | 6.6 EB05 5.7 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.7 · ♀ 87% (drug 57%) | no trial data cached |
| Therapeutic product effect decreased | 114 | 23.4 19.6–28.0ROR 24.6 · χ² 2,425 / p <1e-300 | 23.3 EB05 19.9 · IC025 +4.1 3/3 methods agree | Reporting / coding artifact | serious PRR 35.3 · ♀ 87% (drug 57%) | no trial data cached |
| Cardiac failure congestive | 107 | 12.0 10.0–14.5ROR 12.6 · χ² 1,073 / p 1e-235 | 11.9 EB05 10.1 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 9.4 · ♀ 91% (drug 57%) | no trial data cached |
| Contraindicated product administered | 107 | 32.4 26.9–39.0ROR 33.9 · χ² 3,217 / p <1e-300 | 32.1 EB05 27.3 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | serious PRR 31.0 | no trial data cached |
| Hepatic steatosis | 107 | 52.6 43.7–63.4ROR 55.1 · χ² 5,342 / p <1e-300 | 51.9 EB05 44.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 46.4 · ♀ 88% (drug 57%) | no trial data cached |
| Abdominal discomfort | 106 | 5.8 4.8–7.0ROR 6.0 · χ² 417 / p 6e-93 | 5.6 EB05 4.8 · IC025 +2.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 9.8 · ♀ 94% (drug 57%) | 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.
- Hepatic steatosis — n=107, PRR 52.6
- Sleep disorder due to a general medical condition — n=56, PRR 31.6
- Arteriosclerosis — n=31, PRR 30.0
- Sleep apnoea syndrome — n=57, PRR 27.2
- Atelectasis — n=28, PRR 26.4
- Obstructive airways disorder — n=30, PRR 24.5
- Vasculitis — n=29, PRR 22.7
- Fibromyalgia — n=60, PRR 22.5
- Nodule — n=31, PRR 21.7
- Motor dysfunction — n=22, PRR 19.8
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 Penicillin G?
In FDA FAERS, the most frequently co-reported reaction terms for Penicillin G are drug hypersensitivity, rash, malaise, abdominal pain upper, cough, 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 Penicillin G have an FDA boxed warning?
No. The FDA label retrieved for Penicillin G has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Penicillin G 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 9e58122f-5c75-4905-a774-d3a4dae4ff8c, effective 20260724; matched on
openfda.generic_name.exact:"PENICILLIN G") - 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, 154 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.