THERAPEUTICS

Brands

• Lioresal, Kemstro, Gablofen

Generic?

• Yes

Class

• Muscle relaxant

Commonly Prescribed for

(FDA approved in bold)

• Spasticity and pain related to disorders such as multiple sclerosis (MS) or spinal cord diseases

• Trigeminal neuralgia

• Alcohol withdrawal

• Gastroesophageal reflux disease (GERD)

• Gilles de la Tourette syndrome (GTS)

• Tardive dyskinesias

• Chorea in Huntington's disease

• Acquired peduncular nystagmus

How the Drug Works

• Baclofen is a GABAB agonist. Through mechanisms in addition to GABAB’s inhibitory effect, it depresses monosynaptic and polysynaptic reflex transmission at spinal level but not neuromuscular transmission. However, the exact mechanism of action is unknown. It also has CNS depressant properties

How Long Until It Works

• Pain: hours to weeks

If It Works

• Slowly titrate to most effective dose as tolerated. Many patients will need gradual titration to maintain response and limit sedation

If It Doesn't Work

• Make sure to increase to highest tolerated dose – as high as 200 mg/day. If ineffective, slowly taper and consider alternative treatments for pain. In general, baclofen is more effective for spasticity related to MS or spinal cord disease than for other causes of spasticity

Best Augmenting Combos for Partial Response or Treatment-Resistance

• For focal spasticity, i.e., post-stroke spasticity, botulinum toxin is often more effective and is better tolerated

• Use other centrally acting muscle relaxants with caution due to potential synergistic CNS depressant effect

• Baclofen is usually used in combination with neuroleptics for the treatment of tardive dyskinesias or chorea

• Trigeminal neuralgia often responds to AEDs. Pimozide is another option. For truly refractory patients, surgical interventions may be required

Tests

• None required

ADVERSE EFFECTS (AES)

How the Drug Causes AEs

• Most AEs are related to CNS depression

Notable AEs

• Drowsiness, dizziness, weakness, fatigue are most common. Nausea, constipation, hypotension, and confusion