Lioresal (baclofen)baclofen
According to the FDA label: Baclofen tablets, USP are useful for the alleviation of signs and symptoms of spasticity resulting from multiple sclerosis, particularly for the relief of flexor spasms and concomitant pain, clonus, and muscular rigidity. Patients should have reversible spasticity so that baclofen treatment will aid in restoring residual function. Baclofen tablets, USP may also be of some value in patients with spinal cord injuries and other spinal cord diseases.
83,200 adverse event reports submitted to the FDA (2003–2026)
Top Reported Adverse Events
The most frequently reported events in association with Lioresal (baclofen) in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
Show these terms with plain-language definitions
Tap any term below for a plain-language definition.
Fatigue 6,176 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Drug Ineffective 5,510 reports
A report that the medication did not work as expected for the person taking it. This is a reporting category, not a sign the drug is defective. It simply means someone felt it was not helping their condition.
Full definition in the glossary →Pain 5,446 reports
A general report of physical discomfort, used when no more specific location is given.
Full definition in the glossary →Fall 5,371 reports
A report that the person fell down. Falls are tracked because they can signal issues like dizziness, weakness, or balance problems.
Full definition in the glossary →Nausea 4,581 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →Headache 4,336 reports
Pain in the head or upper neck.
Full definition in the glossary → See all drugs reporting this event →Gait Disturbance 4,092 reports
Difficulty walking normally, such as an unsteady or altered way of walking.
Full definition in the glossary →Off Label Use 3,718 reports
Using a medication for a condition or in a way that the FDA has not officially approved. This is common and often legal, and a report of it does not mean something went wrong. Doctors sometimes prescribe drugs off label based on their judgment.
Full definition in the glossary →Dizziness 3,557 reports
A feeling of being lightheaded, unsteady, or like the room is spinning.
Full definition in the glossary → See all drugs reporting this event →Urinary Tract Infection 3,473 reports
An infection in the bladder, urethra, or kidneys, often called a UTI.
Full definition in the glossary → See all drugs reporting this event →Multiple Sclerosis Relapse 3,400 reports
A return or worsening of multiple sclerosis symptoms. It often appears in reports as part of the condition being treated.
Full definition in the glossary →Asthenia 3,385 reports
Physical weakness or lack of strength.
Full definition in the glossary →Muscle Spasms 3,233 reports
Sudden, involuntary tightening of a muscle, often called cramps.
Full definition in the glossary → See all drugs reporting this event →Diarrhoea 3,065 reports
Loose or watery bowel movements, often frequent. Also spelled diarrhea in American English.
Full definition in the glossary → See all drugs reporting this event →Vomiting 2,799 reports
Throwing up the contents of the stomach.
Full definition in the glossary → See all drugs reporting this event →
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Female | 51,647 |
| Male | 25,771 |
| Unknown | 131 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 2,341 |
| 18-34 | 4,891 |
| 35-49 | 13,435 |
| 50-64 | 21,203 |
| 65-74 | 8,398 |
| 75+ | 3,167 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Lioresal (baclofen). A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Other Serious | 34,236 |
| Non-Serious | 28,160 |
| Hospitalization | 27,271 |
| Death | 6,215 |
| Life-Threatening | 2,645 |
| Disability | 2,124 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Lioresal (baclofen). Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 2003 | 3 |
| 2004 | 646 |
| 2005 | 757 |
| 2006 | 674 |
| 2007 | 796 |
| 2008 | 886 |
| 2009 | 1,032 |
| 2010 | 1,499 |
| 2011 | 1,744 |
| 2012 | 2,516 |
| 2013 | 3,027 |
| 2014 | 4,252 |
| 2015 | 5,157 |
| 2016 | 7,596 |
| 2017 | 7,024 |
| 2018 | 7,705 |
| 2019 | 6,672 |
| 2020 | 5,776 |
| 2021 | 5,484 |
| 2022 | 5,095 |
| 2023 | 5,669 |
| 2024 | 4,218 |
| 2025 | 4,029 |
| 2026 (partial) | 943 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Lioresal (baclofen)
In FDA adverse event reports that mention Lioresal (baclofen), these medications appeared most often in the same report.
- Gabapentin (21,495 reports)
- Ergocalciferol (14,781 reports)
- Dalfampridine (11,475 reports)
- Omeprazole (9,004 reports)
- Pregabalin (8,234 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026