What is the recommended dosage and treatment protocol for Baclofen (GABA receptor agonist) in managing muscle spasticity?

From the Guidelines

Baclofen should be initiated at a low dose of 5 mg three times daily and gradually titrated upward to minimize side effects while achieving therapeutic benefit for muscle spasticity, as supported by the most recent evidence from 2025 1. The dose is usually increased by 5 mg per dose every 3 days until optimal response is achieved, with most patients requiring between 40-80 mg per day divided into three or four doses. Some key points to consider when using Baclofen include:

• The maximum recommended daily dose is generally 80 mg, though some patients with severe spasticity may require up to 120 mg daily under close medical supervision.
• For intrathecal baclofen therapy, which is used when oral therapy is ineffective or poorly tolerated, patients first undergo a screening trial with a single intrathecal injection (typically 50-100 mcg), followed by pump implantation if successful, with maintenance doses typically ranging from 12-1500 mcg/day.
• Treatment should be continued as long as therapeutic benefit is observed, and discontinuation requires gradual tapering to prevent withdrawal symptoms including hallucinations, seizures, and rebound spasticity.
• Baclofen works by activating GABA-B receptors in the spinal cord, hyperpolarizing neurons and reducing the release of excitatory neurotransmitters, thereby decreasing muscle tone and involuntary muscle contractions.
• Common side effects include drowsiness, dizziness, and weakness, which often improve with continued use or dose adjustment. It's also important to note that evidence supports the use of botulinum toxin for patients with focal spasticity depending on patient characteristics and preferences, and that botulinum toxin may not have a dramatically different place in therapy from oral antispasmodics based on efficacy alone 1. In terms of specific patient populations, a small RCT compared the efficacy of botulinum toxin versus oral baclofen in patients with upper- and lower-limb spasticity outcomes, and found no significant difference between the two treatments except for ankle spasticity, which favored botulinum toxin 1. Overall, the use of Baclofen for muscle spasticity should be individualized and based on the specific needs and characteristics of each patient, with careful consideration of the potential benefits and risks of treatment.

From the Research

Recommended Dosage and Treatment Protocol for Baclofen

The recommended dosage and treatment protocol for Baclofen in managing muscle spasticity vary depending on the patient's condition and response to treatment.

• The optimal therapy is the lowest effective dosage, and pharmacotherapy is generally initiated at low dosages and then gradually increased in an attempt to avoid adverse effects 2.
• For oral baclofen, the daily dose can range from 10 to 80 mg, with some patients requiring higher doses for adequate symptomatic relief 3.
• Intrathecal baclofen is indicated for use in patients with spasticity of spinal origin unresponsive to treatment with maximum doses of oral baclofen, tizanidine, and/or dantrolene 4.
• The benefits of continuous intrathecal baclofen infusion have been demonstrated, with >80% and >65% of patients showing improvement in tone and spasms, respectively 4.

Adverse Effects and Risks

The main adverse effects of oral baclofen include sedation or somnolence, excessive weakness, vertigo, and psychological disturbances, with an incidence ranging from 10% to 75% 4.

• The main risks of oral baclofen administration are related to withdrawal, which can cause seizures, psychic symptoms, and hyperthermia 4.
• Intrathecal baclofen infusion can also cause symptoms related to overdose or withdrawal, which can be life-threatening 5.

Comparison with Other Treatments

Baclofen has been compared with other antispasticity drugs, such as tizanidine, and has been found to have equivalent efficacy 4, 6.

• However, tizanidine has been reported to have better tolerability, with less frequent occurrence of weakness compared to baclofen 4, 6.
• Other treatments, such as clonidine, gabapentin, and botulinum toxin, have also shown efficacy in managing spasticity, but more studies are needed to confirm their place in therapy 2.