Baclofen as an adjuvant analgesic.

Baclofen is a gamma-aminobutyric acid (GABA) agonist approved for the treatment of spasticity and commonly used in the management of many types of neuropathic pain. Controlled studies have demonstrated the efficacy of this drug in trigeminal neuralgia. Although its precise mechanism of analgesic action is unknown, it is likely that a drug-induced increase in inhibitory activity is sufficient to interrupt the cascade of neural events that culminates in aberrant activity of wide dynamic range neurons, or more rostral neurons in nociceptive pathways, that is the substrate for some types of neuropathic pain. The optimal use of baclofen as an adjuvant analgesic requires an understanding of its pharmacology, side effect spectrum, and dosing guidelines that have proven useful in clinical practice. Failure of baclofen therapy following a prolonged trial requires dose tapering prior to discontinuation due to the potential for a withdrawal syndrome.