Penicillin G Potassium side effects: what 718 FDA adverse event reports show

Penicillin G Potassium · Penicillin G Potassium · 23 reaction terms · 864 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Brand names

Penicillin G Potassium

openFDA label

Who reports

718 reports · 49% serious · 38 with death outcome · 68% 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 22 strongest signals

Labeled adverse reaction 1Labeled (related wording) 3Reporting / coding artifact 4Lab value / disease marker 2Not in label — unassessed 12

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.
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 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Hepatic steatosis	47	74.2 56.2–97.8ROR 79.3 · χ² 3,314 / p <1e-300	71.9 EB05 56.2 · IC025 +4.9 3/3 methods agree	Not in label — unassessed	serious PRR 98.8 · ♀ 89% (drug 68%)	no trial data cached
Contraindicated product administered	56	54.5 42.3–70.1ROR 59.0 · χ² 2,885 / p <1e-300	53.4 EB05 42.7 · IC025 +4.8 3/3 methods agree	Reporting / coding artifact	serious PRR 79.3	no trial data cached
Drug hypersensitivity	309	46.7 42.9–50.8ROR 81.3 · χ² 13,870 / p <1e-300	46.5 EB05 42.3 · IC025 +5.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 41.8	no trial data cached
Pain in jaw	31	32.1 22.7–45.2ROR 33.5 · χ² 902 / p 2e-198	31.5 EB05 23.2 · IC025 +3.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 59.0 · ♀ 10% (drug 68%)	no trial data cached
Liver disorder	41	27.1 20.2–36.5ROR 28.7 · χ² 1,007 / p 3e-221	26.8 EB05 20.6 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 37.5 · ♀ 100% (drug 68%)	no trial data cached
Therapeutic product effect decreased	41	27.1 20.1–36.5ROR 28.7 · χ² 1,005 / p 7e-221	26.8 EB05 20.6 · IC025 +3.8 3/3 methods agree	Reporting / coding artifact	serious PRR 62.5 · ♀ 100% (drug 68%)	no trial data cached
Synovitis	15	24.4 14.8–40.2ROR 24.9 · χ² 313 / p 2e-70	23.6 EB05 15.1 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 29.9	no trial data cached
Middle insomnia	15	23.6 14.3–39.0ROR 24.1 · χ² 303 / p 4e-68	22.9 EB05 14.6 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 60.3	no trial data cached
Drug intolerance	73	22.2 17.9–27.6ROR 24.6 · χ² 1,464 / p <1e-300	22.1 EB05 18.2 · IC025 +3.9 3/3 methods agree	Reporting / coding artifact	serious PRR 41.8	no trial data cached
Arteriosclerosis	7	21.8 10.4–45.5ROR 22.0 · χ² 119 / p 6e-28	19.5 EB05 8.4 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 26.3	no trial data cached
Hepatic enzyme increased	41	17.7 13.1–23.8ROR 18.7 · χ² 630 / p 2e-139	17.5 EB05 13.4 · IC025 +3.4 3/3 methods agree	Lab value / disease marker	serious PRR 30.0 · ♀ 100% (drug 68%)	no trial data cached
Obstructive airways disorder	6	15.7 7.1–34.9ROR 15.9 · χ² 69 / p 6e-17	12.2 EB05 4.6 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 19.2	no trial data cached
Nodule	7	15.7 7.5–32.8ROR 15.9 · χ² 82 / p 6e-20	12.9 EB05 5.3 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 28.5	no trial data cached
Cardiac failure congestive	43	15.5 11.6–20.8ROR 16.5 · χ² 572 / p 9e-127	15.4 EB05 11.8 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 18.3 · ♀ 97% (drug 68%)	no trial data cached
Vasculitis	6	15.1 6.8–33.5ROR 15.2 · χ² 65 / p 3e-16	11.5 EB05 4.4 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious PRR 19.0	no trial data cached
Cardiac failure (heart failure)	41	15.0 11.1–20.1ROR 15.8 · χ² 522 / p 9e-116	14.7 EB05 11.2 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 17.6 · ♀ 100% (drug 68%)	no trial data cached
Full blood count abnormal	5	13.9 5.8–33.3ROR 14.0 · χ² 48 / p 3e-12	9.5 EB05 3.4 · IC025 +1.1 3/3 methods agree	Lab value / disease marker	serious PRR 21.6	no trial data cached
Anaphylactic reaction (severe allergic reaction)	24	12.8 8.6–19.0ROR 13.2 · χ² 250 / p 1e-56	12.2 EB05 8.2 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 15.3 · ♀ 95% (drug 68%) · 92% clinician	no trial data cached
Sleep disorder due to a general medical condition	7	12.7 6.1–26.5ROR 12.8 · χ² 64 / p 6e-16	9.6 EB05 4.2 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 29.4	no trial data cached
Dermatitis allergic	5	11.8 4.9–28.2ROR 11.8 · χ² 39 / p 2e-10	7.6 EB05 3.0 · IC025 +1.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 20.5	no trial data cached
Rheumatoid arthritis	35	9.1 6.6–12.5ROR 9.5 · χ² 244 / p 2e-55	8.5 EB05 6.2 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 13.0 · ♀ 3% (drug 68%)	no trial data cached
Drug exposure during pregnancy	5	4.2 1.8–10.2ROR 4.3 · χ² 9 / p 0.001	3.2 EB05 1.6 · IC025 +0.2	Reporting / coding artifact	serious PRR 5.5	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	309	46.7 42.9–50.8ROR 81.3 · χ² 13,870 / p <1e-300	46.5 EB05 42.3 · IC025 +5.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 41.8	no trial data cached
Drug intolerance	73	22.2 17.9–27.6ROR 24.6 · χ² 1,464 / p <1e-300	22.1 EB05 18.2 · IC025 +3.9 3/3 methods agree	Reporting / coding artifact	serious PRR 41.8	no trial data cached
Contraindicated product administered	56	54.5 42.3–70.1ROR 59.0 · χ² 2,885 / p <1e-300	53.4 EB05 42.7 · IC025 +4.8 3/3 methods agree	Reporting / coding artifact	serious PRR 79.3	no trial data cached
Hepatic steatosis	47	74.2 56.2–97.8ROR 79.3 · χ² 3,314 / p <1e-300	71.9 EB05 56.2 · IC025 +4.9 3/3 methods agree	Not in label — unassessed	serious PRR 98.8 · ♀ 89% (drug 68%)	no trial data cached
Cardiac failure congestive	43	15.5 11.6–20.8ROR 16.5 · χ² 572 / p 9e-127	15.4 EB05 11.8 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 18.3 · ♀ 97% (drug 68%)	no trial data cached
Cardiac failure (heart failure)	41	15.0 11.1–20.1ROR 15.8 · χ² 522 / p 9e-116	14.7 EB05 11.2 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 17.6 · ♀ 100% (drug 68%)	no trial data cached
Hepatic enzyme increased	41	17.7 13.1–23.8ROR 18.7 · χ² 630 / p 2e-139	17.5 EB05 13.4 · IC025 +3.4 3/3 methods agree	Lab value / disease marker	serious PRR 30.0 · ♀ 100% (drug 68%)	no trial data cached
Therapeutic product effect decreased	41	27.1 20.1–36.5ROR 28.7 · χ² 1,005 / p 7e-221	26.8 EB05 20.6 · IC025 +3.8 3/3 methods agree	Reporting / coding artifact	serious PRR 62.5 · ♀ 100% (drug 68%)	no trial data cached
Liver disorder	41	27.1 20.2–36.5ROR 28.7 · χ² 1,007 / p 3e-221	26.8 EB05 20.6 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 37.5 · ♀ 100% (drug 68%)	no trial data cached
Rheumatoid arthritis	35	9.1 6.6–12.5ROR 9.5 · χ² 244 / p 2e-55	8.5 EB05 6.2 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 13.0 · ♀ 3% (drug 68%)	no trial data cached
Pain in jaw	31	32.1 22.7–45.2ROR 33.5 · χ² 902 / p 2e-198	31.5 EB05 23.2 · IC025 +3.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 59.0 · ♀ 10% (drug 68%)	no trial data cached
Anaphylactic reaction (severe allergic reaction)	24	12.8 8.6–19.0ROR 13.2 · χ² 250 / p 1e-56	12.2 EB05 8.2 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 15.3 · ♀ 95% (drug 68%) · 92% clinician	no trial data cached
Middle insomnia	15	23.6 14.3–39.0ROR 24.1 · χ² 303 / p 4e-68	22.9 EB05 14.6 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 60.3	no trial data cached
Synovitis	15	24.4 14.8–40.2ROR 24.9 · χ² 313 / p 2e-70	23.6 EB05 15.1 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 29.9	no trial data cached
Sleep disorder due to a general medical condition	7	12.7 6.1–26.5ROR 12.8 · χ² 64 / p 6e-16	9.6 EB05 4.2 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 29.4	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=47, PRR 74.2
Liver disorder — n=41, PRR 27.1
Cardiac failure congestive — n=43, PRR 15.5
Cardiac failure — n=41, PRR 15.0
Rheumatoid arthritis — n=35, PRR 9.1

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, hepatic steatosis, cardiac failure congestive, cardiac failure, hepatic enzyme increased, liver disorder. 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, field patient.drug.openfda.generic_name.exact, 23 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.