Generic name
Naloxone hydrochloride: adverse event reports filed with FDA
537 reports list it as a suspect or interacting product, 2009–2026. Class: Opioid antagonist.
- 537
- reports as suspect product
- 0% of all reports · about 31 a year
- 61
- reports, 12 months to June 2026
- 85 in the 12 months before
- 73.4%
- marked serious by the reporter
- 62.4% across the class
- 13.2%
- record death among outcomes, as reported
- 71 reports · not verified by FDA
537 adverse event reports received by FDA list naloxone hydrochloride, a generic name as a suspect or interacting product, from May 2009 to June 2026. A further 373 reports list it only as a concomitant medication, and those are not counted in the figures on this page.
In the 12 months to June 2026, 61 reports listed it, down 28% from 85 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 31 reports a year and 0% of the 20,646,523 reports in the database, and 1.7% of the reports for the opioid antagonist class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded drug ineffective (15.5%), toxicity to various agents (10.4%) and drug withdrawal syndrome (7.8%). A report can list several reactions, so shares add to more than 100%; 208 different terms appear across these reports. Drug ineffective is recorded in 15.5% of these reports, a larger share than in the median opioid antagonist drug (10.1%).
73.4% of the reports are marked serious by the reporter (62.4% across the class); 13.2% record death among the outcomes and 33.7% record hospitalisation, as reported. 46.4% of the reports came from other health professionals, and the largest patient age group is 18 to 44 (25.9%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Naloxone hydrochloride reports recording the termmedian drug in opioid antagonist
- Drug ineffectivethe medicine did not work as expected15.5%83
- Toxicity to various agentspoisoning or toxic effect of one or more substances10.4%56
- Drug withdrawal syndromesymptoms on stopping a medicine7.8%42
- Overdosea dose above the recommended amount5.4%29
- Vomitingbeing sick4.8%26
- Drug abusemisuse of a medicine4.5%24
- Drug dependencedependence on a medicine4.5%24
- Off label useused for a purpose or in a way not on the label4.3%23
- Maternal exposure during pregnancythe mother took the medicine during pregnancy3.5%19
- Rhesus incompatibility3.5%19
- Drug diversion3.4%18
- Pulmonary oedemafluid in the lungs3.4%18
- Fatiguetiredness3.2%17
- Foetal exposure during pregnancythe unborn baby was exposed to the medicine3.2%17
- Painpain, site not specified3.2%17
- Premature babya baby born early2.8%15
- Premature delivery2.8%15
- Therapy non-responderthe treatment did not work2.8%15
- Transfusion2.8%15
- Confusional stateconfusion2.6%14
- Falla fall2.6%14
- Dyspnoeashortness of breath2.4%13
- Product use issuea problem in how the product was used2.4%13
- Chillschills or shivering2.2%12
- Headachehead pain2.2%12
- Irritabilityirritability2.2%12
- Loss of consciousnesspassing out2.2%12
- Memory impairmentmemory problems2.2%12
- Somnolencedrowsiness2.2%12
Top 30 of 208 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 10 drugs in the opioid antagonist class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 31,239 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 71.9% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Overdose | 125 | 23.3% |
| Toxicity to various agents | 28 | 5.2% |
| Drug abuse | 21 | 3.9% |
| Drug dependence | 15 | 2.8% |
| Back pain | 4 | 0.7% |
| Drug use disorder | 4 | 0.7% |
The indication field is filled in by the reporter and is often blank; shares are of all 537 reports.
In context
| Measure | Naloxone hydrochloride | Opioid antagonist | All reports |
|---|---|---|---|
| Reports as suspect product | 537 | 31,239 | 20,646,523 |
| Share of that pool | — | 1.7% | 0% |
| Reports, latest 12 months | 61 | — | 1,332,454 |
| Marked serious | 73.4% | 62.4% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 132 | 87 | 91 |
| Hospitalisation recorded, per 1,000 reports | 337 | 204 | 213 |
| Consumer-filed share | 35.9% | 48.6% | 45.8% |
| Top term, share of reports | Drug ineffective 15.5% | median 10.1% | 6.3% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the opioid antagonist class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Suboxone | brand | 20,919 | 552 | 66.8% |
| Movantik | brand | 1,997 | 45 | 26.9% |
| Buprenorphine and naloxone | generic | 1,935 | 66 | 53.7% |
| Naloxone | generic | 1,693 | 129 | 94.2% |
| Relistor | brand | 978 | 28 | 55.4% |
| Zubsolv | brand | 973 | 44 | 21% |
| Narcan | brand | 835 | 38 | 56.2% |
| Buprenorphine hydrochloride, naloxone hydrochloride | generic | 824 | 77 | 57.9% |
| Symproic | brand | 548 | 13 | 47.3% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Naloxone hydrochloride reports
How many adverse event reports has FDA received for Naloxone hydrochloride?
537 reports list Naloxone hydrochloride as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 61 of them arrived in the latest 12 months. Another 373 list it only as a concomitant medication.
What reactions are recorded in Naloxone hydrochloride reports?
drug ineffective (15.5%), toxicity to various agents (10.4%), drug withdrawal syndrome (7.8%), overdose (5.4%) and vomiting (4.8%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Naloxone hydrochloride was responsible.
How serious are the reports?
73.4% are marked serious by the reporter. Among the outcomes recorded, 13.2% of reports include death and 33.7% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (46.4%), consumer or non-health professional (35.9%) and physician (14.3%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Naloxone hydrochloride rising?
61 reports in the 12 months to June 2026, down 28% from 85 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Naloxone hydrochloride was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Naloxone hydrochloride?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Naloxone hydrochloride as a suspect or interacting product; reports listing it only as a concomitant medication (373) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.