Class: Centrally Acting Skeletal Muscle Relaxant
Dosage Forms. Tablet: 10 mg, 20 mg
Common FDA Label Indication, Dosing, and Titration.
1. Spasticity: 5 mg orally tid; may increase dose in 15 mg/d increments to a max of 80 mg/d in 3-4 divided doses
1. Intractable hiccoughs, 5 mg po bid, increasing to 15-45 mg/d in 3 divided doses
MOA. Baclofen inhibits both monosynaptic and polysynaptic reflexes at the spinal level, possibly by hyperpolarization of afferent terminals, although actions at supraspinal sites may also occur and contribute to its clinical effect. Baclofen is an analog of gamma-aminobutyric acid (GABA), but there is no conclusive evidence that actions on GABA systems are involved in the production of its clinical effects.
Drug Characteristics: Baclofen
Medication Safety Issues: Baclofen
Drug Interactions: Baclofen. None known
Adverse Reactions: Baclofen
Efficacy Monitoring Parameters. Reduction in muscle spasm, passive limb movement, pain relief.
Toxicity Monitoring Parameters. Seek medical attention if severe dizziness, confusion, sedation, or rebound spasticity occurs.
Key Patient Counseling Points. Because of the possibility of sedation, patients should be cautioned regarding the operation of motor vehicles or dangerous machinery while taking baclofen. Patients should be cautioned that the CNS effects of baclofen may be additive to those of alcohol and other CNS depressants.
Clinical Pearls. Implantable pumps that administer baclofen intrathecally are also available for patients with spasticity. Constipation occurs in 100% of patients undergoing intrathecal administration, and abrupt discontinuation of intrathecal therapy (intentional or inadvertent) is commonly fatal.