Baclofen is a centrally-acting skeletal muscle relaxant, classified pharmacologically as a gamma-aminobutyric acid (GABAB) receptor agonist. It is primarily indicated for the management of muscle spasticity resulting from multiple sclerosis, spinal cord injuries, and other spinal cord diseases. By inhibiting monosynaptic and polysynaptic reflexes at the spinal level, baclofen reduces the frequency and amplitude of muscle spasms, thereby alleviating pain, discomfort, and improving functional capacity. Its efficacy is well-documented in clinical settings, making it a first-line therapeutic option for patients experiencing significant spasticity that interferes with daily activities or rehabilitation.

Features

• Active pharmaceutical ingredient: Baclofen
• Available in oral tablets (10 mg, 20 mg) and intrathecal solution for infusion
• Mechanism of action: GABAB receptor agonist
• Half-life: approximately 2.5–4 hours
• Metabolism: hepatic (minimal)
• Excretion: primarily renal (70–80% unchanged)
• Prescription-only medication

Benefits

• Significantly reduces muscle spasticity and associated clonus
• Decreases painful muscle spasms, improving comfort and sleep quality
• Enhances range of motion and voluntary motor function
• May improve mobility and ability to perform activities of daily living
• Reduces resistance to passive movement, facilitating nursing care and physiotherapy
• Can be administered via intrathecal pump for severe, refractory cases

Common use

Baclofen is most commonly prescribed for the symptomatic treatment of spasticity, particularly in conditions such as multiple sclerosis, spinal cord injury, transverse myelitis, and amyotrophic lateral sclerosis (ALS). It is also used off-label for the management of certain types of chronic hiccups, trigeminal neuralgia, and alcohol withdrawal syndrome, though evidence supporting these uses is less robust. The oral formulation is typically initiated in patients with moderate to severe spasticity that impairs function, while the intrathecal route is reserved for severe spasticity unresponsive to oral agents or when side effects are intolerable.

Dosage and direction

Dosage must be individualized based on patient response and tolerability. For oral administration in adults, the initial dose is usually 5 mg three times daily, which may be increased by 5 mg every three days to a maximum of 80 mg daily (20 mg qid). For intrathecal use, dosage is titrated via programmable pump, with screening doses typically ranging from 25–100 mcg. Abrupt discontinuation should be avoided due to risk of withdrawal symptoms, including hallucinations and seizures. Dosage reduction is necessary in patients with renal impairment.

Precautions

Baclofen should be used with caution in patients with a history of seizure disorders, psychiatric conditions, stroke, or renal impairment. It may cause drowsiness, dizziness, or blurred vision, affecting the ability to operate machinery or drive. Elderly patients may be more sensitive to its effects, particularly sedation and confusion. Alcohol and other CNS depressants may potentiate these effects. Regular monitoring of renal function is advised during long-term therapy.

Contraindications

Baclofen is contraindicated in patients with hypersensitivity to baclofen or any component of the formulation. It should not be used in those with significant respiratory depression or compromised pulmonary function. The intrathecal formulation is contraindicated in patients with infection at the injection site or systemic infection. Use is also contraindicated in patients with active peptic ulcer disease or a history of gastrointestinal bleeding.

Possible side effect

Common adverse effects include drowsiness, dizziness, weakness, fatigue, nausea, and headache. Less frequently, patients may experience confusion, hypotension, insomnia, constipation, or urinary retention. Serious side effects can include respiratory depression, hallucinations, seizures (particularly upon abrupt withdrawal), and severe hypotonia. Intrathecal administration carries additional risks such as catheter-related complications, meningitis, and pump malfunction.

Drug interaction

Baclofen may interact additively with other CNS depressants, including opioids, benzodiazepines, alcohol, sedatives, and tricyclic antidepressants, increasing the risk of respiratory depression and excessive sedation. Concurrent use with monoamine oxidase inhibitors (MAOIs) may potentiate hypotensive effects. Caution is advised when administering with antihypertensives due to possible additive hypotension.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose. In that case, skip the missed dose and resume the regular schedule. Do not double the dose to make up for a missed one, as this may increase the risk of adverse effects.

Overdose

Symptoms of overdose may include vomiting, muscular hypotonia, drowsiness, coma, respiratory depression, and seizures. Management is primarily supportive, including airway protection and ventilatory support if needed. There is no specific antidote; hemodialysis may be considered in severe cases due to baclofen’s renal excretion.

Storage

Store at room temperature (20–25°C), away from light and moisture. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging. Intrathecal solution should be stored according to the manufacturer’s instructions, typically refrigerated until use.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and individualized treatment recommendations. Do not initiate, adjust, or discontinue baclofen without medical supervision.

Reviews

Clinical studies and patient reports consistently affirm baclofen’s efficacy in reducing spasticity and improving quality of life. Many patients note significant functional improvement, though side effects like drowsiness are commonly reported. Intrathecal baclofen is often described as life-changing for those with severe spasticity unresponsive to oral therapy. Long-term adherence is generally good when dosage is carefully titrated.