Naloxone Hydrochloride side effects: what 4,746 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Naloxone Hydrochloride
Who reports
4,746 reports · 71% serious · 730 with death outcome · 56% female
Used for
(s) to “revive” someone during an overdose from many prescription pain medications or street drugs such as heroin this medicine can save a life
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
What the badges mean
- 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.
- No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.
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. 401 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 |
|---|---|---|---|---|---|---|
| Premature delivery | 47 | 13.0 9.8–17.3ROR 13.1 · χ² 508 / p 1e-112 | 12.7 EB05 9.8 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.7 · ♀ 100% (drug 56%) | no trial data cached |
| Acute respiratory failure | 53 | 12.3 9.4–16.0ROR 12.4 · χ² 535 / p 1e-118 | 12.0 EB05 9.4 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.7 | no trial data cached |
| Hospice care | 27 | 12.1 8.3–17.7ROR 12.2 · χ² 264 / p 1e-59 | 11.5 EB05 8.0 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.3 | no trial data cached |
| Dental caries | 28 | 11.2 7.7–16.2ROR 11.3 · χ² 250 / p 1e-56 | 10.5 EB05 7.4 · IC025 +2.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 11.5 | no trial data cached |
| Unresponsive to stimuli | 65 | 11.2 8.8–14.2ROR 11.3 · χ² 592 / p 6e-131 | 10.9 EB05 8.8 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.0 · ♀ 34% (drug 56%) | no trial data cached |
| Malnutrition | 27 | 10.8 7.4–15.7ROR 10.8 · χ² 229 / p 6e-52 | 10.0 EB05 7.0 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.0 | no trial data cached |
| Transfusion | 25 | 10.5 7.1–15.6ROR 10.6 · χ² 205 / p 7e-47 | 9.7 EB05 6.6 · IC025 +2.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.9 | no trial data cached |
| Atelectasis | 22 | 10.0 6.6–15.2ROR 10.1 · χ² 170 / p 4e-39 | 9.1 EB05 6.1 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.2 | no trial data cached |
| Intervertebral disc degeneration | 19 | 9.0 5.8–14.1ROR 9.1 · χ² 128 / p 7e-30 | 7.9 EB05 5.2 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.3 | no trial data cached |
| Sickle cell anaemia with crisis | 31 | 8.7 6.1–12.3ROR 8.7 · χ² 203 / p 3e-46 | 8.0 EB05 5.8 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.1 | no trial data cached |
| Impaired gastric emptying | 24 | 8.3 5.6–12.4ROR 8.4 · χ² 147 / p 4e-34 | 7.5 EB05 5.2 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.5 · ♀ 78% (drug 56%) | no trial data cached |
| Drug withdrawal syndrome | 150 | 7.5 6.4–8.8ROR 7.7 · χ² 837 / p 2e-184 | 7.3 EB05 6.4 · IC025 +2.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 | no trial data cached |
| End stage renal disease | 31 | 7.4 5.2–10.6ROR 7.5 · χ² 166 / p 2e-38 | 6.8 EB05 5.0 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.0 | no trial data cached |
| Respiratory depression | 20 | 7.2 4.7–11.2ROR 7.2 · χ² 101 / p 5e-24 | 6.3 EB05 4.3 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.0 | no trial data cached |
| Mental status changes | 43 | 6.8 5.1–9.2ROR 6.9 · χ² 208 / p 1e-47 | 6.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.1 | no trial data cached |
| Oral candidiasis (oral thrush) | 20 | 6.8 4.4–10.5ROR 6.8 · χ² 93 / p 3e-22 | 6.0 EB05 4.1 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.7 | no trial data cached |
| Blood calcium decreased | 17 | 6.7 4.1–10.7ROR 6.7 · χ² 76 / p 1e-18 | 5.7 EB05 3.8 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious PRR 6.3 | no trial data cached |
| Bursitis | 18 | 6.6 4.2–10.5ROR 6.6 · χ² 80 / p 2e-19 | 5.7 EB05 3.8 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.9 | no trial data cached |
| Chronic kidney disease | 114 | 6.6 5.5–7.9ROR 6.7 · χ² 534 / p 2e-118 | 6.4 EB05 5.5 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.4 | no trial data cached |
| Osteopenia | 22 | 6.4 4.2–9.7ROR 6.4 · χ² 94 / p 1e-22 | 5.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.1 | no trial data cached |
| Anhedonia | 38 | 6.3 4.6–8.7ROR 6.4 · χ² 166 / p 3e-38 | 5.9 EB05 4.5 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.7 | no trial data cached |
| Insurance issue | 21 | 6.2 4.1–9.6ROR 6.3 · χ² 87 / p 5e-21 | 5.6 EB05 3.8 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.9 | no trial data cached |
| Haematocrit decreased | 28 | 6.2 4.3–9.0ROR 6.2 · χ² 117 / p 2e-27 | 5.7 EB05 4.1 · IC025 +1.9 3/3 methods agree | Lab value / disease marker | serious PRR 5.4 · ♀ 29% (drug 56%) | no trial data cached |
| Tooth abscess | 14 | 6.1 3.6–10.2ROR 6.1 · χ² 54 / p 1e-13 | 5.1 EB05 3.2 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.0 | no trial data cached |
| Tooth fracture | 15 | 6.0 3.6–10.0ROR 6.0 · χ² 58 / p 2e-14 | 5.1 EB05 3.3 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.4 | no trial data cached |
| Vitamin d deficiency | 13 | 5.9 3.4–10.1ROR 5.9 · χ² 48 / p 2e-12 | 5.0 EB05 3.1 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.7 | no trial data cached |
| Leukocytosis | 24 | 5.9 3.9–8.7ROR 5.9 · χ² 92 / p 4e-22 | 5.3 EB05 3.7 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.8 | no trial data cached |
| Toxicity to various agents | 222 | 5.8 5.1–6.6ROR 6.1 · χ² 893 / p 2e-196 | 5.8 EB05 5.2 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.8 | no trial data cached |
| Iron deficiency anaemia | 12 | 5.8 3.3–10.2ROR 5.8 · χ² 43 / p 3e-11 | 4.8 EB05 2.9 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.9 | no trial data cached |
| Ocular discomfort | 14 | 5.7 3.4–9.6ROR 5.7 · χ² 50 / p 1e-12 | 4.9 EB05 3.1 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=11 | no trial data cached |
| Hypoxia (low oxygen) | 45 | 5.7 4.2–7.6ROR 5.7 · χ² 169 / p 8e-39 | 5.4 EB05 4.2 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.6 | no trial data cached |
| Sinus tachycardia | 18 | 5.6 3.5–8.9ROR 5.6 · χ² 64 / p 7e-16 | 5.0 EB05 3.3 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.6 | no trial data cached |
| Withdrawal syndrome | 53 | 5.5 4.2–7.3ROR 5.6 · χ² 193 / p 3e-44 | 5.3 EB05 4.2 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.9 · 82% consumer | no trial data cached |
| Spinal operation | 15 | 5.5 3.3–9.1ROR 5.5 · χ² 50 / p 6e-13 | 4.7 EB05 3.1 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 4.5 | no trial data cached |
| Feeling cold | 34 | 5.4 3.9–7.5ROR 5.4 · χ² 117 / p 1e-27 | 5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.4 · 79% consumer | no trial data cached |
| Generalised oedema | 15 | 5.4 3.2–8.9ROR 5.4 · χ² 49 / p 1e-12 | 4.7 EB05 3.0 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.8 | no trial data cached |
| Joint range of motion decreased | 16 | 5.3 3.2–8.6ROR 5.3 · χ² 51 / p 4e-13 | 4.6 EB05 3.0 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.4 | no trial data cached |
| Brain injury | 12 | 5.3 3.0–9.3ROR 5.3 · χ² 37 / p 5e-10 | 4.5 EB05 2.7 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.3 | no trial data cached |
| Caesarean section | 14 | 5.3 3.1–8.9ROR 5.3 · χ² 44 / p 2e-11 | 4.5 EB05 2.9 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.4 | no trial data cached |
| Premature baby | 35 | 5.1 3.7–7.1ROR 5.2 · χ² 112 / p 2e-26 | 4.8 EB05 3.6 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.2 | 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 |
|---|---|---|---|---|---|---|
| Pain | 344 | 2.5 2.2–2.7ROR 2.6 · χ² 308 / p 3e-69 | 2.5 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.5 | no trial data cached |
| Death | 293 | 1.5 1.3–1.7ROR 1.5 · χ² 51 / p 5e-13 | 1.5 EB05 1.4 · IC025 +0.4 | Outcome field, not a reaction | serious PRR 1.2 | no trial data cached |
| Vomiting | 284 | 2.7 2.4–3.0ROR 2.8 · χ² 303 / p 4e-68 | 2.7 EB05 2.4 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.3 | no trial data cached |
| Toxicity to various agents | 222 | 5.8 5.1–6.6ROR 6.1 · χ² 893 / p 2e-196 | 5.8 EB05 5.2 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.8 | no trial data cached |
| Overdose | 211 | 4.3 3.8–4.9ROR 4.5 · χ² 537 / p 5e-119 | 4.3 EB05 3.8 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious PRR 3.8 | no trial data cached |
| Fall | 204 | 2.7 2.4–3.1ROR 2.8 · χ² 222 / p 2e-50 | 2.7 EB05 2.4 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.4 | no trial data cached |
| Anxiety | 170 | 2.6 2.3–3.1ROR 2.7 · χ² 173 / p 1e-39 | 2.6 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.5 | no trial data cached |
| Drug withdrawal syndrome | 150 | 7.5 6.4–8.8ROR 7.7 · χ² 837 / p 2e-184 | 7.3 EB05 6.4 · IC025 +2.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 | no trial data cached |
| Drug dependence | 149 | 4.0 3.5–4.7ROR 4.1 · χ² 341 / p 2e-76 | 4.0 EB05 3.5 · IC025 +1.7 3/3 methods agree | Reporting / coding artifact | serious PRR 3.2 · 83% consumer | no trial data cached |
| Back pain | 140 | 2.7 2.3–3.1ROR 2.7 · χ² 145 / p 1e-33 | 2.6 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.9 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 138 | 4.0 3.4–4.7ROR 4.1 · χ² 310 / p 1e-69 | 4.0 EB05 3.4 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.2 | no trial data cached |
| Constipation | 136 | 2.8 2.4–3.3ROR 2.8 · χ² 154 / p 1e-35 | 2.8 EB05 2.4 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.3 | no trial data cached |
| Product dose omission issue | 134 | 2.1 1.8–2.5ROR 2.1 · χ² 75 / p 3e-18 | 2.1 EB05 1.8 · IC025 +0.8 | Reporting / coding artifact | serious PRR 4.4 · 73% consumer | no trial data cached |
| Urinary tract infection (bladder infection) | 128 | 3.3 2.8–3.9ROR 3.4 · χ² 207 / p 3e-47 | 3.3 EB05 2.8 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.0 · ♀ 80% (drug 56%) | no trial data cached |
| Somnolence (drowsiness) | 124 | 2.7 2.3–3.2ROR 2.8 · χ² 135 / p 2e-31 | 2.7 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.8 | no trial data cached |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
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 Naloxone?
In FDA FAERS, the most frequently co-reported reaction terms for Naloxone are pain, vomiting, toxicity to various agents, fall, anxiety, drug withdrawal syndrome. 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 Naloxone have an FDA boxed warning?
No. The FDA label retrieved for Naloxone has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Naloxone 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 8779a073-dc6e-410a-9959-fd370f0079f9, effective 20240419; matched on
openfda.generic_name.exact:"NALOXONE") - 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, 441 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.