Baclofène

Baclofène, known in English as baclofen, is a prescription medication used primarily as a muscle relaxant to treat spasticity from conditions such as multiple sclerosis, spinal cord injury, stroke, or cerebral palsy. It is also used off-label in some countries to treat alcohol use disorder, though this use is not universally approved and remains controversial.

Baclofen is a gamma-aminobutyric acid type B (GABA-B) receptor agonist. By activating GABA-B receptors in the central nervous system, it reduces neuronal excitability and the transmission of signals that contribute to spasticity. It is available as oral tablets and, for severe spasticity, as intrathecal baclofen delivered by an implanted pump.

Dosing begins with low amounts and is titrated slowly to minimize side effects. Typical oral doses range from 15 to 80 mg per day in divided doses; higher daily doses (up to about 100–200 mg) may be used under medical supervision. Intrathecal baclofen is reserved for patients with refractory spasticity. If a treatment is stopped, gradual tapering is essential to reduce withdrawal risk.

Common adverse effects include drowsiness, dizziness, fatigue, weakness, headache, nausea, and low blood pressure. Cognitive effects and confusion can occur, particularly in older patients. Baclofen withdrawal after abrupt discontinuation, especially of intrathecal therapy, can cause hyperthermia, severe spasticity, autonomic instability, and seizures; reinstitution and careful tapering are required.

Safety considerations include adjustment for renal impairment, since baclofen is primarily excreted by the kidneys. It can interact with other central nervous system depressants to increase sedation. Use during pregnancy should be limited to situations where benefits justify potential risks; it is often avoided during breastfeeding.