Key Takeaways
- Baclofen side effects affect approximately 10-63% of users, with drowsiness and dizziness being the most frequently reported.
- Serious side effects include seizures, hallucinations, respiratory depression, and severe allergic reactions.
- Baclofen withdrawal syndrome can be life-threatening and may include high fever, psychosis, seizures, and rhabdomyolysis.
- Elderly patients and those with kidney disease are at higher risk for severe side effects.
- Combining baclofen with alcohol, opioids, or benzodiazepines significantly increases the risk of respiratory depression and death.
- Long-term baclofen use can cause cognitive impairment, mood changes, and physical dependence.
What Are the Side Effects of Baclofen?
Baclofen is a GABA-B receptor agonist prescribed primarily for muscle spasticity. While it is effective for many patients, it carries a range of side effects from mild to potentially life-threatening. Understanding these side effects is essential for anyone taking or considering baclofen.
Common Side Effects
The most frequently reported baclofen side effects include:
- Drowsiness (up to 63% of users) — the most common complaint
- Dizziness (up to 15%)
- Weakness and fatigue (up to 15%)
- Nausea (up to 12%)
- Headache (up to 8%)
- Constipation (up to 6%)
- Insomnia (despite causing drowsiness, some patients report difficulty sleeping)
- Dry mouth
- Urinary frequency or retention
These side effects are typically most pronounced when starting the medication or increasing the dose, and they often improve over time.
Serious Side Effects
Less common but more concerning side effects include:
- Seizures: Particularly during abrupt withdrawal, but can also occur during use
- Hallucinations: Visual and auditory hallucinations have been reported, especially in elderly patients
- Respiratory depression: Slow, shallow breathing, particularly when combined with other CNS depressants
- Severe hypotension: Dangerously low blood pressure
- Mood changes: Depression, suicidal ideation, anxiety, and emotional instability
- Cognitive impairment: Memory problems, confusion, and difficulty concentrating
- Liver toxicity: Rare but documented cases of elevated liver enzymes
The Danger of Baclofen Withdrawal
One of the most dangerous aspects of baclofen is the severity of its withdrawal syndrome. Stopping baclofen suddenly after regular use can cause:
- High fever (hyperthermia)
- Severe muscle spasticity (worse than before treatment)
- Seizures (sometimes status epilepticus)
- Hallucinations and psychosis
- Rhabdomyolysis (muscle breakdown that can cause kidney failure)
- Multi-organ failure
- Death
Baclofen withdrawal has been compared in severity to alcohol and benzodiazepine withdrawal. It requires medical supervision and a gradual tapering schedule.
If you or a loved one is facing these challenges, learn more about safely managing medications during recovery available at Trailhead Treatment Center in Salem, NH.
Who Is at Higher Risk for Side Effects?
Certain populations face elevated risks:
- Elderly patients: More susceptible to drowsiness, falls, and confusion
- Patients with kidney disease: Baclofen is renally excreted; impaired kidneys lead to drug accumulation
- People who use alcohol: Alcohol amplifies baclofen's sedative and respiratory depressant effects
- Patients on opioids or benzodiazepines: Combining CNS depressants increases the risk of fatal respiratory depression
Trailhead Treatment Center provides talk to our team about medication concerns to support lasting recovery and wellness.
Conclusion
Baclofen can be an effective medication when used properly, but its side effects — particularly the dangers of abrupt withdrawal — require careful medical oversight. If you are experiencing concerning side effects or want to stop taking baclofen, consult your healthcare provider before making any changes. Trailhead Treatment Center provides comprehensive medication management and substance abuse treatment services.