Per Ertzgaard, Claudia Campo, Alessandra Calabrese
Department of Rehabilitation Medicine, Linköping University Hospital , SE-581 85 Linköping, Sweden. E-mail: per.ertzgaard@liu.se
DOI: 10.2340/16501977-2211

Oral baclofen has long been a mainstay in the management of spasticity. This review looks at the clinical evidence for the efficacy and safety of oral baclofen in patients with spasticity of any origin or severity, to determine whether there is a rationale for the use of intrathecal baclofen. Results suggest that oral baclofen may be effective in many patients with spasticity, regardless of the underlying disease or severity, and that it is at least comparable with other antispasmodic agents. However, adverse effects, such as muscle weakness, nausea, somnolence and paraesthesia, are common with oral baclofen, affecting between 25% and 75% of patients, and limiting its usefulness. Intrathecal baclofen may be an effective alternative as the drug is delivered directly into the cerebrospinal fluid, thus bypassing the blood-brain barrier and thereby optimizing the efficacy of baclofen while minimizing drug-related side-effects. Intrathecal baclofen is a viable option in patients who experience intolerable side-effects or who fail to respond to the maximum recommended dose of oral baclofen.

Oral baclofen for the treatment of spasticity: when it works, and when intrathecal administration should be considered
Spasticity is characterized by overactivity of the muscles and increased muscle tone. Treatment of spasticity is necessary when the condition begins to interfere with daily activities. First-line treatment comprises orally-administered anti-spasmodic agents, with baclofen being used most frequently. This review of available clinical studies shows that baclofen given orally is effective in decreasing spasticity. However, side effects such as muscle weakness, nausea and somnolence are often experienced by patients, thus limiting the quantity of medication that can be administered. The infusion of baclofen directly into the intrathecal space of the spine should be considered as an alternative. This mode of delivery allows baclofen to be administered close to the site of action, and is known to provide effectiveness at much smaller doses. Intrathecal baclofen can be an option for patients who experience intolerable side effects or who do not achieve adequate spasticity relief with the maximum recommended dosage of oral baclofen.

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