Reported Reactions

Drugs › Expectorant

Brand name · Guaifenesin and dextromethorphan hydrobromide

Mucinex Dm Maximum Strength: adverse event reports filed with FDA

3,328 reports list it as a suspect or interacting product, 2012–2026. Class: Expectorant.

3,328
reports as suspect product
0% of all reports · about 241 a year
177
reports, 12 months to June 2026
234 in the 12 months before
11.5%
marked serious by the reporter
33.2% across the class
0.1%
record death among outcomes, as reported
2 reports · not verified by FDA

Between September 2012 and June 2026, 3,328 adverse event reports received by FDA list the brand name Mucinex Dm Maximum Strength (guaifenesin and dextromethorphan hydrobromide) as a suspect or interacting product. Reports that mention it only as a concomitant medication (39) are left out of every figure here.

In the 12 months to June 2026, 177 reports listed it, down 24% from 234 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 241 reports a year and 0% of the 20,646,523 reports in the database, and 6.5% of the reports for the expectorant 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 dizziness (15.1%), accidental overdose (14.3%) and drug ineffective (13.2%). A report can list several reactions, so shares add to more than 100%; 221 different terms appear across these reports. Dizziness is recorded in 15.1% of these reports, a larger share than in the median expectorant drug (7.1%).

11.5% of the reports are marked serious by the reporter (33.2% across the class); 0.1% record death among the outcomes and 1.1% record hospitalisation, as reported. 98.2% of the reports came from consumers, and the largest patient age group is 75 and over (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

0161321Jul 2021: 59Aug 2021: 29Sep 2021: 0Oct 2021: 0Nov 2021: 0Dec 2021: 22022Jan 2022: 1Feb 2022: 2Mar 2022: 0Apr 2022: 1May 2022: 1Jun 2022: 1Jul 2022: 200Aug 2022: 0Sep 2022: 0Oct 2022: 6Nov 2022: 0Dec 2022: 12023Jan 2023: 3Feb 2023: 3Mar 2023: 0Apr 2023: 1May 2023: 0Jun 2023: 0Jul 2023: 321Aug 2023: 0Sep 2023: 0Oct 2023: 1Nov 2023: 1Dec 2023: 02024Jan 2024: 2Feb 2024: 2Mar 2024: 3Apr 2024: 2May 2024: 255Jun 2024: 1Jul 2024: 1Aug 2024: 1Sep 2024: 3Oct 2024: 1Nov 2024: 4Dec 2024: 12025Jan 2025: 1Feb 2025: 0Mar 2025: 1Apr 2025: 0May 2025: 97Jun 2025: 124Jul 2025: 1Aug 2025: 0Sep 2025: 4Oct 2025: 2Nov 2025: 1Dec 2025: 02026Jan 2026: 1Feb 2026: 0Mar 2026: 0Apr 2026: 1May 2026: 0Jun 2026: 167

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

02084162012: 1820122013: 682014: 3620142015: 372016: 32620162017: 4162018: 40220182019: 3722020: 33820202021: 962022: 21320222023: 3302024: 27620242025: 2312026: 1692026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Mucinex Dm Maximum Strength reports recording the termmedian drug in expectorant

  1. Dizzinesslight-headedness or unsteadiness15.1%503
  2. Accidental overdosean accidental overdose14.3%475
  3. Drug ineffectivethe medicine did not work as expected13.2%439
  4. Overdosea dose above the recommended amount9.8%327
  5. Diarrhoealoose or frequent stools8.8%293
  6. Nauseafeeling sick6.9%229
  7. Product use in unapproved indicationused for a purpose not on the label6.4%212
  8. Somnolencedrowsiness4.9%164
  9. Feeling abnormalfeeling odd or not right4.3%142
  10. Wrong technique in product usage processthe product was used in the wrong way3.8%126
  11. Vomitingbeing sick3.6%121
  12. Insomniadifficulty sleeping3.4%114
  13. Inappropriate schedule of product administrationthe product was taken at the wrong times3.3%111
  14. No adverse eventno adverse event was reported3.2%106
  15. Headachehead pain3.1%103
  16. Expired product administeredthe product was used past its expiry date3%100
  17. Abdominal pain upperupper stomach pain2.8%92
  18. Fatiguetiredness2.5%83
  19. Dyspnoeashortness of breath2.1%70
  20. Condition aggravatedthe condition being treated got worse1.9%63
  21. Astheniaweakness or lack of energy1.7%57
  22. Coughcough1.7%55
  23. Anxietyanxiety1.6%52
  24. Palpitationsawareness of the heartbeat1.6%52
  25. Confusional stateconfusion1.5%51

Top 30 of 221 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 expectorant 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

Death0.1%2
Life-threatening0.2%6
Hospitalisation (initial or prolonged)1.1%37
Disability0%1
Congenital anomaly0%0
Other serious11.1%371
Not serious88.5%2,944

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 51,345 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%1
2 to 110.3%10
12 to 171.8%61
18 to 4411.4%381
45 to 6417.8%594
65 to 7414.1%469
75 and over20.4%680
Age not given34%1,132

Patient sex

Female59.9%1,995
Male30.8%1,024
Not given9.3%309

Who reported

Physician0.2%6
Pharmacist0%0
Other health professional1.6%52
Lawyer0%0
Consumer or non-health professional98.2%3,268
Not given0.1%2

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 100% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Cough54516.4%
Nasopharyngitis1444.3%
Respiratory tract congestion1253.8%
Productive cough902.7%
Covid-19341%
Chronic obstructive pulmonary disease200.6%

The indication field is filled in by the reporter and is often blank; shares are of all 3,328 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Mucinex Dm Maximum Strength reports
Lisinopril431.3%
Metformin421.3%
Amlodipine371.1%
Losartan371.1%
Metoprolol361.1%
Mucinex351.1%
Atorvastatin290.9%
Aspirin270.8%
Levothyroxine200.6%
Synthroid190.6%

Other products listed in reports where Mucinex Dm Maximum Strength 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

MeasureMucinex Dm Maximum StrengthExpectorantAll reports
Reports as suspect product3,32851,34520,646,523
Share of that pool—6.5%0%
Reports, latest 12 months177—1,332,454
Marked serious11.5%33.2%57.4%
Death recorded among outcomes, per 1,000 reports15091
Hospitalisation recorded, per 1,000 reports1196213
Consumer-filed share98.2%80.8%45.8%
Top term, share of reportsDizziness 15.1%median 7.1%2.4%

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 expectorant class

DrugName typeReportsLatest 12 monthsMarked serious
Tylenolbrand30,7265,53639.8%
Mucinexbrand5,10735119.8%
Delsymbrand3,57914415%
Mucinex DMbrand2,42211928%
Mucinex Maximum Strengthbrand2,2271877.1%
Dextromethorphan hydrobromidegeneric1,67011675.5%
Guaifenesingeneric1,20810845.6%
Dextromethorphan hydrobromide,guaifenesingeneric57613912.7%
Mucinex Dbrand5022434.1%

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 Mucinex Dm Maximum Strength reports

How many adverse event reports has FDA received for Mucinex Dm Maximum Strength?

3,328 reports list Mucinex Dm Maximum Strength as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 177 of them arrived in the latest 12 months. Another 39 list it only as a concomitant medication.

What reactions are recorded in Mucinex Dm Maximum Strength reports?

dizziness (15.1%), accidental overdose (14.3%), drug ineffective (13.2%), overdose (9.8%) and diarrhoea (8.8%). 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 Mucinex Dm Maximum Strength was responsible.

How serious are the reports?

11.5% are marked serious by the reporter. Among the outcomes recorded, 0.1% of reports include death and 1.1% 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 (98.2%), other health professional (1.6%) and physician (0.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Mucinex Dm Maximum Strength rising?

177 reports in the 12 months to June 2026, down 24% from 234 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 Mucinex Dm Maximum Strength 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 Mucinex Dm Maximum Strength?

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 Mucinex Dm Maximum Strength as a suspect or interacting product; reports listing it only as a concomitant medication (39) 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.