Side Effects of Baclofen in Patients with Alcohol Use Disorders
Baclofen, a GABA-B receptor agonist used as a muscle relaxant, has shown benefit in maintaining alcohol abstinence in patients with alcohol use disorders, but comes with several potential side effects that require monitoring.
Common Side Effects
- Transient drowsiness is the most common side effect, affecting 10-63% of patients taking baclofen 1
- Disruption of wake-sleep cycle affects approximately 63% of patients and is the most frequently reported group of adverse effects 2
- Dizziness (5-15%), weakness (5-15%), and fatigue (2-4%) are other common side effects 1
- Neuropsychiatric effects include confusion (1-11%), headache (4-8%), and insomnia (2-7%) 1
Serious Side Effects
- Impaired mentation is a significant concern, particularly in patients with advanced liver disease or hepatic encephalopathy 3
- Hypotension occurs in up to 9% of patients 1
- Potentially dangerous adverse effects include bouts of somnolence and hypomanic episodes 2
- Seizures can occur, particularly during withdrawal from baclofen 4
- Baclofen withdrawal syndrome characterized by confusion, agitation, seizures, and delirium may be mistaken for alcohol withdrawal syndrome 4
Special Considerations for AUD Patients
- Baclofen is the only AUD pharmacotherapy tested in a randomized controlled trial specifically in patients with alcoholic cirrhosis 3
- Patients with hepatic encephalopathy were excluded from trials due to baclofen's potential to impair mentation 3
- Women report significantly more adverse effects than men when taking high-dose baclofen 2
- Risk of abuse exists due to baclofen's mood-elevating properties, particularly in patients with comorbid depression 5
Dosing and Toxicity Considerations
- Standard dosing for alcohol use disorders ranges from 30-60 mg/day 3
- High-dose baclofen (up to 270 mg/day) has been studied with individually titrated dosing 6
- Mean dosage at onset of first adverse effect is approximately 83 mg/day 2
- Doses above 180 mg are associated with severe toxicity and potential death in overdose situations 7
- Persistent adverse effects occur in about 53% of patients 2
Monitoring and Management
- Careful monitoring is required when initiating baclofen, particularly in patients with advanced liver disease 3
- Approximately 7% of patients discontinue baclofen due to adverse effects, typically at doses below 90 mg/day 2
- Alertness disorders and depression are the adverse effects most frequently leading to discontinuation 2
- No antidote is available for baclofen toxicity; treatment is only symptomatic 7
- Laboratory abnormalities may include increased SGOT, elevated alkaline phosphatase, and elevation of blood sugar 1
Risk Assessment
- Self-poisoning risk is higher in patients with alcohol use disorders due to frequent comorbid psychiatric conditions 7
- Potential co-ingestants should be considered, especially CNS depressants 7
- Baclofen withdrawal syndrome can be mistaken for alcohol withdrawal syndrome, as both present with confusion, agitation, seizures, and delirium 4