Baclofen

Overview

Baclofen is a centrally acting skeletal muscle relaxant and a derivative of gamma-aminobutyric acid (GABA). It is used primarily to reduce muscle spasticity, stiffness, and pain associated with conditions such as multiple sclerosis, spinal cord injury, and other spinal cord disorders. Baclofen is available as oral tablets and as an intrathecal solution for severe spasticity.

How Baclofen works

Baclofen works by activating GABA-B receptors in the central nervous system, particularly in the spinal cord. This action inhibits the release of excitatory neurotransmitters and reduces the transmission of monosynaptic and polysynaptic reflexes at the spinal level. In plain terms, it calms overactive nerve signals that cause muscles to tighten and spasm, helping to relieve spasticity and improve mobility.

Uses

• Relief of spasticity associated with multiple sclerosis
• Spasticity due to spinal cord injury or disease
• Other spinal cord disorders causing muscle spasticity
• Intrathecal baclofen for severe, chronic spasticity unresponsive to oral therapy
• Off-label use in some settings for alcohol use disorder (to reduce craving)

Side effects

• Drowsiness or sedation
• Dizziness or lightheadedness
• Weakness or fatigue
• Headache
• Nausea
• Confusion
• Low blood pressure (hypotension)
• Serious: difficulty breathing or respiratory depression
• Serious: seizures or hallucinations (especially if stopped suddenly)
• Serious: severe mood or mental changes (e.g., mania, psychosis)
• Serious: inability to urinate (urinary retention)

Precautions

• Do not stop baclofen suddenly; withdrawal can cause seizures, hallucinations, confusion, and rebound spasticity. Taper under medical supervision.
• Use with caution in patients with kidney disease; dose adjustment may be needed.
• Caution in elderly patients and those with a history of seizures, stroke, or psychiatric disorders.
• Avoid alcohol and other central nervous system depressants (e.g., opioids, benzodiazepines, sleep medicines) due to additive drowsiness and breathing risk.
• May lower blood pressure; caution with antihypertensive medications.
• Not recommended during pregnancy or breastfeeding unless clearly needed; consult doctor.
• Intrathecal baclofen should only be administered by trained healthcare professionals; pump malfunction or abrupt interruption can be life-threatening.
• Allergic/hypersensitivity to baclofen is a contraindication.