Lioresal (Baclofen)

Lioresal (baclofen) is employed as an antispastic agent for conditions that cause increased muscle tone due to central nervous system damage.

• Multiple sclerosis–related spasticity: reduces muscle tone and improves mobility in affected patients.
• Spinal cord injury–induced spasticity: lessens involuntary muscle contractions and facilitates rehabilitation.
• Cerebral palsy–associated spasticity: helps control muscle stiffness and enhances functional movement.
• Neurogenic spasticity of other etiologies: provides symptomatic relief of muscle hypertonia when other causes are excluded.

• Baclofen acts as an agonist at GABA_B receptors located on pre‑ and postsynaptic neurons in the spinal cord. Activation of these metabotropic receptors inhibits the release of excitatory neurotransmitters such as glutamate and aspartate, leading to reduced neuronal firing and decreased reflex‑mediated muscle contraction. By modulating spinal interneuron activity, baclofen also dampens the stretch reflex, contributing to overall muscle relaxation.

Baclofen may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Drowsiness: feeling unusually sleepy or reduced alertness.
• Weakness: generalized muscle weakness or fatigue affecting daily tasks.
• Dizziness: sensation of light‑headedness or imbalance, especially when standing quickly.
• Nausea: mild stomach upset or urge to vomit.
• Headache: mild to moderate pain in the head region.
• Dry mouth: reduced salivation leading to a parched feeling.

Serious or Rare Side Effects

• Seizures: occurrence of convulsive episodes, potentially life‑threatening.
• Respiratory depression: slowed or shallow breathing requiring medical attention.
• Allergic reactions: rash, itching, swelling, or anaphylaxis indicating hypersensitivity.
• Hallucinations: visual or auditory disturbances that may impair perception.
• Severe hypotension: marked drop in blood pressure causing faintness.

When prescribing baclofen, clinicians should consider several precautionary measures to ensure safe use.

• Renal impairment: adjust dose or monitor closely in patients with reduced kidney function.
• Hepatic disease: use caution as metabolism may be altered in liver dysfunction.
• Concomitant CNS depressants: avoid additive sedation when combined with alcohol or opioids.
• Sudden discontinuation: taper gradually to prevent withdrawal symptoms such as agitation or seizures.
• Pregnancy and lactation: limited data; weigh potential benefits against unknown risks.
• Store at ambient temperature: keep tablets below 25 °C in the original container, protected from moisture and light.

Baclofen can interact with other medicines, influencing its efficacy or safety profile.

Major Interactions (Avoid)

• Opioids: combined use may cause profound respiratory depression and excessive sedation.
• Antihypertensives: additive hypotensive effect may lead to dangerously low blood pressure.
• CNS depressants (e.g., benzodiazepines, barbiturates): risk of enhanced central nervous system depression.

Moderate Interactions (Monitor Closely)

• Anticonvulsants: may alter seizure threshold; monitor for breakthrough seizures.
• CYP450 inhibitors (e.g., erythromycin): can increase baclofen plasma levels, requiring dose adjustment.
• Alcohol: potentiates sedative effects and may increase dizziness.