Reported Reactions

Drugs › Cholinesterase inhibitor

Brand name · Pyridostigmine bromide oral

Pyridostigmine: adverse event reports filed with FDA

930 reports list it as a suspect or interacting product, 2008–2026. Class: Cholinesterase inhibitor. Also reported as Pyridostigmine 60mg, Pyridostigmine 60mg Tab.

930
reports as suspect product
0% of all reports · about 52 a year
153
reports, 12 months to June 2026
130 in the 12 months before
84.5%
marked serious by the reporter
88.6% across the class
6.9%
record death among outcomes, as reported
64 reports · not verified by FDA

930 adverse event reports received by FDA list the brand name Pyridostigmine (pyridostigmine bromide oral) as a suspect or interacting product, from October 2008 to June 2026. A further 2,523 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, 153 reports listed it, up 18% from 130 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 52 reports a year and 0% of the 20,646,523 reports in the database, and 3.6% of the reports for the cholinesterase inhibitor 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 (20.8%), off label use (16.6%) and myasthenia gravis (10.3%). A report can list several reactions, so shares add to more than 100%; 259 different terms appear across these reports. Drug ineffective is recorded in 20.8% of these reports, a larger share than in the median cholinesterase inhibitor drug (4.7%).

84.5% of the reports are marked serious by the reporter (88.6% across the class); 6.9% record death among the outcomes and 36.8% record hospitalisation, as reported. 65.2% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (23.4%). 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

02142Jul 2021: 16Aug 2021: 10Sep 2021: 4Oct 2021: 7Nov 2021: 11Dec 2021: 112022Jan 2022: 4Feb 2022: 1Mar 2022: 5Apr 2022: 6May 2022: 5Jun 2022: 3Jul 2022: 13Aug 2022: 3Sep 2022: 6Oct 2022: 9Nov 2022: 6Dec 2022: 262023Jan 2023: 12Feb 2023: 7Mar 2023: 38Apr 2023: 1May 2023: 4Jun 2023: 2Jul 2023: 6Aug 2023: 5Sep 2023: 5Oct 2023: 12Nov 2023: 6Dec 2023: 62024Jan 2024: 8Feb 2024: 6Mar 2024: 13Apr 2024: 17May 2024: 13Jun 2024: 3Jul 2024: 16Aug 2024: 9Sep 2024: 9Oct 2024: 11Nov 2024: 9Dec 2024: 182025Jan 2025: 14Feb 2025: 5Mar 2025: 10Apr 2025: 11May 2025: 9Jun 2025: 9Jul 2025: 11Aug 2025: 23Sep 2025: 42Oct 2025: 16Nov 2025: 8Dec 2025: 102026Jan 2026: 11Feb 2026: 7Mar 2026: 11Apr 2026: 7May 2026: 3Jun 2026: 4

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

0841682008: 220082012: 72013: 1820132014: 132015: 2520152016: 332017: 3820172018: 562019: 3820192020: 672021: 9920212022: 872023: 10420232024: 1322025: 16820252026: 43

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Pyridostigmine reports recording the termmedian drug in cholinesterase inhibitor

  1. Drug ineffectivethe medicine did not work as expected20.8%193
  2. Off label useused for a purpose or in a way not on the label16.6%154
  3. Condition aggravatedthe condition being treated got worse7.7%72
  4. Therapy non-responderthe treatment did not work5.4%50
  5. Myasthenia gravis crisis4.9%46
  6. Diarrhoealoose or frequent stools4.6%43
  7. Astheniaweakness or lack of energy3.9%36
  8. Weight increasedweight gain3.4%32
  9. Nauseafeeling sick3.3%31
  10. Respiratory failurethe lungs could not supply enough oxygen3.2%30
  11. Covid-19COVID-19 infection2.8%26
  12. Fatiguetiredness2.7%25
  13. Product use in unapproved indicationused for a purpose not on the label2.7%25
  14. Bradycardiaslow heart rate2.4%22
  15. Maternal exposure during pregnancythe mother took the medicine during pregnancy2.2%20
  16. Muscular weaknessmuscle weakness2.2%20
  17. Oedema peripheralswelling of the legs, ankles or hands2%19
  18. Headachehead pain1.8%17
  19. Dyspnoeashortness of breath1.7%16
  20. Exposure during pregnancythe medicine was taken during pregnancy1.7%16
  21. Insomniadifficulty sleeping1.7%16
  22. Dizzinesslight-headedness or unsteadiness1.6%15
  23. Osteoporosisthinning of the bones1.6%15

Top 30 of 259 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 8 drugs in the cholinesterase inhibitor 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

Death6.9%64
Life-threatening11.5%107
Hospitalisation (initial or prolonged)36.8%342
Disability3.2%30
Congenital anomaly0.3%3
Other serious61.8%575
Not serious15.5%144

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 25,719 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 20.3%3
2 to 112%19
12 to 171.1%10
18 to 4419.2%179
45 to 6423.4%218
65 to 7419.4%180
75 and over19.1%178
Age not given15.4%143

Patient sex

Female53.4%497
Male38.1%354
Not given8.5%79

Who reported

Physician19.8%184
Pharmacist3.4%32
Other health professional65.2%606
Lawyer0%0
Consumer or non-health professional10%93
Not given1.6%15

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 53% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Myasthenia gravis52856.8%
Congenital myasthenic syndrome242.6%
Myocarditis-myositis-myasthenia gravis overlap syndrome192%
Ocular myasthenia151.6%
Intestinal pseudo-obstruction131.4%
Muscular weakness131.4%

The indication field is filled in by the reporter and is often blank; shares are of all 930 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Pyridostigmine reports
Prednisone28130.2%
Mycophenolate mofetil17118.4%
Prednisolone16617.8%
Azathioprine13014%
Methylprednisolone10211%
Human immunoglobulin g849%
Rituximab677.2%
Immune globulin555.9%
Tacrolimus414.4%
Pembrolizumab323.4%

Other products listed in reports where Pyridostigmine 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

MeasurePyridostigmineCholinesterase inhibitorAll reports
Reports as suspect product93025,71920,646,523
Share of that pool—3.6%0%
Reports, latest 12 months153—1,332,454
Marked serious84.5%88.6%57.4%
Death recorded among outcomes, per 1,000 reports6923091
Hospitalisation recorded, per 1,000 reports368369213
Consumer-filed share10%38.7%45.8%
Top term, share of reportsDrug ineffective 20.8%median 4.7%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 cholinesterase inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Exelonbrand13,66326592.6%
Ariceptbrand4,0434383.2%
Rivastigminegeneric2,60225776.4%
Donepezil hydrochloridegeneric1,56913692%
Galantamine hydrobromidegeneric1,1632896.7%
Mestinonbrand9604971.7%
Galantaminegeneric7893795.1%

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 Pyridostigmine reports

How many adverse event reports has FDA received for Pyridostigmine?

930 reports list Pyridostigmine as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 153 of them arrived in the latest 12 months. Another 2,523 list it only as a concomitant medication.

What reactions are recorded in Pyridostigmine reports?

drug ineffective (20.8%), off label use (16.6%), myasthenia gravis (10.3%), condition aggravated (7.7%) and therapy non-responder (5.4%). 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 Pyridostigmine was responsible.

How serious are the reports?

84.5% are marked serious by the reporter. Among the outcomes recorded, 6.9% of reports include death and 36.8% 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 (65.2%), physician (19.8%) and consumer or non-health professional (10%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Pyridostigmine rising?

153 reports in the 12 months to June 2026, up 18% from 130 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 Pyridostigmine 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 Pyridostigmine?

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 Pyridostigmine as a suspect or interacting product; reports listing it only as a concomitant medication (2,523) 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.