Pharmacologic class (EPC) · 3 drug pages

gamma-Aminobutyric acid-ergic agonist: adverse event reports filed with FDA

35,901 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

35,901
reports across the class: 0.2% of all reports; 1,274
reports, 12 months to June 2026: 1,414 in the 12 months before; 77.9%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

gamma-Aminobutyric acid-ergic agonist is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 35,901 adverse event reports received by FDA, 0.2% of the database, from January 2004 to June 2026.

1,274 reports arrived in the 12 months to June 2026, down 10% from 1,414 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 77.9% of the class's reports are marked serious, 12.5% record death among the outcomes and 34% record hospitalisation, as reported.

Across the class the reactions recorded most often are muscle spasticity (11.6%), drug ineffective (9.1%) and drug withdrawal syndrome (8.5%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Baclofen	generic	21,650	1,174	85.2%	Toxicity to various agents
Lioresal (baclofen)Baclofen	brand	11,183	7	71.5%	Muscle spasticity
GablofenBaclofen injection	brand	3,068	93	50.2%	Muscle spasticity

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Muscle spasticity11.6%4,154
Drug ineffectivethe medicine did not work as expected9.1%3,250
Drug withdrawal syndromesymptoms on stopping a medicine8.5%3,039
Painpain, site not specified7.5%2,698
Overdosea dose above the recommended amount6.6%2,376
Toxicity to various agentspoisoning or toxic effect of one or more substances5.9%2,106
Hypertonia5.7%2,039
Somnolencedrowsiness5.2%1,867
Muscle spasmsmuscle cramps5%1,801
Completed suicidedeath by suicide4%1,428
Off label useused for a purpose or in a way not on the label3.9%1,418
Coma3.9%1,392
Withdrawal syndrome3.7%1,316
Falla fall3.4%1,231
Nauseafeeling sick3.4%1,215
Vomitingbeing sick3.2%1,144
Headachehead pain3%1,094
Pruritusitching2.9%1,057
Pyrexiafever2.9%1,028
Confusional stateconfusion2.8%1,021
Dizzinesslight-headedness or unsteadiness2.7%981
Therapeutic response decreasedthe medicine worked less well2.6%939
Hypotonia2.6%937
Encephalopathy2.6%929
Implant site infection2.6%928

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death12.5%4,474

Life-threatening5.2%1,849

Hospitalisation (initial or prolonged)34%12,211

Disability1.3%462

Congenital anomaly0.1%30

Other serious53.1%19,077

Not serious22.1%7,921

Patient age

Under 20.3%109

2 to 112.9%1,037

12 to 173.2%1,153

18 to 4417.6%6,327

45 to 6422.5%8,066

65 to 747%2,527

75 and over3.4%1,218

Age not given43.1%15,464

Who reported

Physician33.7%12,103

Pharmacist4.4%1,562

Other health professional28.1%10,101

Lawyer0.2%63

Consumer or non-health professional25.9%9,295

Not given7.7%2,777

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about gamma-Aminobutyric acid-ergic agonist reports

Which drugs are in the gamma-Aminobutyric acid-ergic agonist class on this site?

Baclofen, Lioresal (baclofen) and Gablofen. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

35,901 reports through June 2026, 1,274 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

muscle spasticity (11.6%), drug ineffective (9.1%), drug withdrawal syndrome (8.5%), pain (7.5%) and overdose (6.6%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.