What is the maximum recommended dose of Baclofen (GABA receptor agonist) for an adult patient with normal renal function?

Maximum Recommended Dose of Baclofen

The maximum recommended dose of baclofen for adults with normal renal function is 80 mg per day, typically divided into four doses of 20 mg each. 1, 2

Standard Dosing Guidelines

• The FDA-approved maximum daily dose is 80 mg per day (20 mg four times daily), which should not be exceeded according to the official drug label. 2
• The American Geriatrics Society confirms this conventional maximum daily dose of 80 mg per day for muscle relaxant therapy. 1
• French guidelines for alcohol-related liver disease also support a maximum daily dose of 80 mg of baclofen. 1

Titration Schedule to Maximum Dose

The FDA recommends a structured titration approach to reach the maximum dose: 2

• Start at 5 mg three times daily for 3 days
• Increase to 10 mg three times daily for 3 days
• Increase to 15 mg three times daily for 3 days
• Increase to 20 mg three times daily for 3 days
• Further increases may be made thereafter, but total daily dose should not exceed 80 mg daily (20 mg four times daily) 2

Important Caveats for Special Populations

Elderly Patients

• Elderly patients rarely tolerate doses greater than 30-40 mg per day due to increased risk of muscle weakness, urinary dysfunction, cognitive effects, and sedation. 1
• The American Geriatrics Society recommends starting at 5 mg up to three times daily (15 mg/day total) for older adults, with careful monitoring during titration. 1
• Even though the official maximum is 80 mg/day, practical tolerance in elderly patients is substantially lower, making 30-40 mg/day a more realistic ceiling for this population. 1

Evidence for Higher Doses

While the FDA-approved maximum is 80 mg/day, research evidence suggests some patients may require higher doses: 2

• A 1992 study confirmed the safety and efficacy of high-dose baclofen exceeding the conventional 80 mg daily maximum in patients requiring adequate symptomatic relief for spasticity. 3
• A 2019 ICU study administered daily doses of 150 mg in patients with preserved renal function without toxic plasma concentrations. 4
• A 2018 population pharmacokinetics study in alcohol-dependent patients used doses ranging from 15 to 250 mg daily, with 26% receiving more than 120 mg/day, demonstrating linear pharmacokinetics even at high doses. 5

However, these higher doses represent off-label use and should only be considered in specialized settings with close monitoring, as they exceed FDA-approved dosing. 2

Critical Safety Warnings

• Never discontinue baclofen abruptly—the American Geriatrics Society warns that abrupt discontinuation can result in a potentially severe withdrawal syndrome with central nervous system irritability. 1
• If benefits are not evident after a reasonable trial period at the maximum tolerated dose, patients should be slowly withdrawn from the drug. 2
• The lowest dose compatible with an optimal response is recommended. 2

Renal Function Considerations

• Baclofen pharmacokinetics are significantly affected by renal function, with renal failure increasing baclofen exposure and decreasing clearance. 4
• A 2019 study suggested dose reductions of approximately 40%, 60%, and 70% in patients with mild, moderate, and severe renal failure, respectively. 4
• For patients with normal renal function, the standard 80 mg/day maximum applies without adjustment. 2