Reported Reactions

Drugs › Opioid antagonist

Brand name · Naloxone hydrochloride

Narcan: adverse event reports filed with FDA

835 reports list it as a suspect or interacting product, 2004–2026. Class: Opioid antagonist.

835
reports as suspect product
0% of all reports · about 38 a year
38
reports, 12 months to June 2026
127 in the 12 months before
56.2%
marked serious by the reporter
62.4% across the class
21.2%
record death among outcomes, as reported
177 reports · not verified by FDA

835 adverse event reports received by FDA list the brand name Narcan (naloxone hydrochloride) as a suspect or interacting product, from July 2004 to June 2026. A further 3,012 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, 38 reports listed it, down 70% from 127 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 38 reports a year and 0% of the 20,646,523 reports in the database, and 2.7% 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.

The reactions recorded most often are toxicity to various agents (13.8%), overdose (13.1%) and drug withdrawal syndrome (9.3%). A report can list several reactions, so shares add to more than 100%; 201 different terms appear across these reports. Toxicity to various agents is recorded in 13.8% of these reports, a larger share than in the median opioid antagonist drug (1.4%).

56.2% of the reports are marked serious by the reporter (62.4% across the class); 21.2% record death among the outcomes and 22.4% record hospitalisation, as reported. 59.4% of the reports came from consumers, and the largest patient age group is 45 to 64 (20.4%). 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

01224Jul 2021: 14Aug 2021: 5Sep 2021: 6Oct 2021: 2Nov 2021: 9Dec 2021: 32022Jan 2022: 10Feb 2022: 9Mar 2022: 5Apr 2022: 3May 2022: 8Jun 2022: 2Jul 2022: 1Aug 2022: 4Sep 2022: 1Oct 2022: 8Nov 2022: 4Dec 2022: 52023Jan 2023: 0Feb 2023: 10Mar 2023: 1Apr 2023: 0May 2023: 1Jun 2023: 5Jul 2023: 0Aug 2023: 3Sep 2023: 1Oct 2023: 6Nov 2023: 11Dec 2023: 122024Jan 2024: 3Feb 2024: 7Mar 2024: 2Apr 2024: 3May 2024: 6Jun 2024: 2Jul 2024: 10Aug 2024: 10Sep 2024: 4Oct 2024: 6Nov 2024: 14Dec 2024: 52025Jan 2025: 16Feb 2025: 19Mar 2025: 24Apr 2025: 9May 2025: 1Jun 2025: 9Jul 2025: 7Aug 2025: 2Sep 2025: 3Oct 2025: 8Nov 2025: 7Dec 2025: 42026Jan 2026: 2Feb 2026: 2Mar 2026: 1Apr 2026: 0May 2026: 1Jun 2026: 1

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

0711412004: 120042005: 22006: 42007: 620072008: 132009: 42010: 520102011: 82012: 32013: 220132014: 112015: 52016: 11620162017: 272018: 512019: 2320192020: 1412021: 1152022: 6020222023: 502024: 722025: 10920252026: 7

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Narcan reports recording the termmedian drug in opioid antagonist

  1. Toxicity to various agentspoisoning or toxic effect of one or more substances13.8%115
  2. Overdosea dose above the recommended amount13.1%109
  3. Drug withdrawal syndromesymptoms on stopping a medicine9.3%78
  4. Drug dependencedependence on a medicine8.4%70
  5. Unintentional use for unapproved indication7.7%64
  6. Vomitingbeing sick6.8%57
  7. Deaththe patient died; cause not stated by this term5.3%44
  8. Painpain, site not specified4.8%40
  9. Maternal exposure during pregnancythe mother took the medicine during pregnancy3.7%31
  10. Feeling abnormalfeeling odd or not right3.5%29
  11. Emotional distressemotional distress3%25
  12. Malaisegeneral feeling of being unwell3%25
  13. Anger2.9%24
  14. Drug ineffectivethe medicine did not work as expected2.9%24
  15. Loss of consciousnesspassing out2.5%21
  16. Premature babya baby born early2.5%21
  17. Anxietyanxiety2.4%20
  18. Dizzinesslight-headedness or unsteadiness2.4%20
  19. Diarrhoealoose or frequent stools2.3%19
  20. Somnolencedrowsiness2.3%19
  21. Drug abusemisuse of a medicine1.9%16
  22. Dyspnoeashortness of breath1.9%16
  23. Fatiguetiredness1.9%16
  24. Falla fall1.8%15
  25. Nauseafeeling sick1.8%15
  26. Astheniaweakness or lack of energy1.7%14
  27. Seizurea fit or convulsion1.7%14
  28. Aggressionaggressive behaviour1.6%13

Top 30 of 201 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

Death21.2%177
Life-threatening5%42
Hospitalisation (initial or prolonged)22.4%187
Disability2.3%19
Congenital anomaly0.1%1
Other serious35.2%294
Not serious43.8%366

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

Under 20.5%4
2 to 110.1%1
12 to 170.5%4
18 to 4418.7%156
45 to 6420.4%170
65 to 743%25
75 and over1.8%15
Age not given55.1%460

Patient sex

Female41.6%347
Male44.6%372
Not given13.9%116

Who reported

Physician4.9%41
Pharmacist3.2%27
Other health professional26.9%225
Lawyer3.5%29
Consumer or non-health professional59.4%496
Not given2%17

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 78.7% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Overdose29535.3%
Pain30.4%
Drug therapy20.2%
Drug use disorder20.2%
Euphoric mood20.2%

The indication field is filled in by the reporter and is often blank; shares are of all 835 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Narcan reports
Fentanyl13916.6%
Heroin9411.3%
Caffeine8610.3%
Oxycodone hydrochloride839.9%
Methamphetamine728.6%
Nicotine607.2%
OxyContin556.6%
Diazepam526.2%
Amphetamine445.3%
Buprenorphine425%

Other products listed in reports where Narcan is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureNarcanOpioid antagonistAll reports
Reports as suspect product83531,23920,646,523
Share of that pool—2.7%0%
Reports, latest 12 months38—1,332,454
Marked serious56.2%62.4%57.4%
Death recorded among outcomes, per 1,000 reports2128791
Hospitalisation recorded, per 1,000 reports224204213
Consumer-filed share59.4%48.6%45.8%
Top term, share of reportsToxicity to various agents 13.8%median 1.4%0.8%

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

DrugName typeReportsLatest 12 monthsMarked serious
Suboxonebrand20,91955266.8%
Movantikbrand1,9974526.9%
Buprenorphine and naloxonegeneric1,9356653.7%
Naloxonegeneric1,69312994.2%
Relistorbrand9782855.4%
Zubsolvbrand9734421%
Buprenorphine hydrochloride, naloxone hydrochloridegeneric8247757.9%
Symproicbrand5481347.3%
Naloxone hydrochloridegeneric5376173.4%

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 Narcan reports

How many adverse event reports has FDA received for Narcan?

835 reports list Narcan as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 38 of them arrived in the latest 12 months. Another 3,012 list it only as a concomitant medication.

What reactions are recorded in Narcan reports?

toxicity to various agents (13.8%), overdose (13.1%), drug withdrawal syndrome (9.3%), drug dependence (8.4%) and unintentional use for unapproved indication (7.7%). 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 Narcan was responsible.

How serious are the reports?

56.2% are marked serious by the reporter. Among the outcomes recorded, 21.2% of reports include death and 22.4% 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?

consumer or non-health professional (59.4%), other health professional (26.9%) and physician (4.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Narcan rising?

38 reports in the 12 months to June 2026, down 70% from 127 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 Narcan 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 Narcan?

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 Narcan as a suspect or interacting product; reports listing it only as a concomitant medication (3,012) 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.