Naxalgan (Pregabalin)

Pregabalin acts on the nervous system to reduce abnormal neuronal firing associated with seizures and neuropathic pain.

• Partial onset seizures: reduces seizure frequency in patients with epilepsy.
• Diabetic peripheral neuropathic pain: alleviates pain and improves sensory function in diabetic patients.
• Postherpetic neuralgia: decreases persistent pain following shingles.
• Fibromyalgia: lessens widespread musculoskeletal pain and improves quality of life.
• Generalized anxiety disorder: diminishes anxiety symptoms and promotes calmness.

• Pregabalin binds selectively to the α2δ subunit of voltage‑gated calcium channels in the central nervous system, decreasing calcium influx into presynaptic neurons. This action reduces the release of excitatory neurotransmitters such as glutamate, norepinephrine, and substance P, thereby dampening neuronal hyperexcitability that underlies seizures, neuropathic pain, and anxiety.

Pregabalin may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Dizziness: sensation of light‑headedness or unsteadiness.
• Somnolence: increased sleepiness or fatigue.
• Peripheral edema: swelling of the lower extremities.
• Weight gain: gradual increase in body weight.
• Dry mouth: reduced salivation leading to oral discomfort.
• Blurred vision: temporary visual disturbances.

Serious or Rare Side Effects

• Angioedema: rapid swelling of face, lips, tongue, or throat requiring emergency care.
• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Suicidal thoughts: emergence of depressive symptoms or suicidal ideation.
• Respiratory depression: especially when combined with other CNS depressants.
• Cardiac failure: worsening of pre‑existing heart failure symptoms.

Before initiating therapy, clinicians should evaluate patient‑specific factors and monitor for potential risks.

• Assess renal function: adjust dose in patients with impaired clearance.
• Monitor for suicidal ideation: counsel patients and caregivers about mood changes.
• Avoid abrupt discontinuation: taper dose under medical supervision to prevent withdrawal.
• Use caution in pregnancy: limited data; weigh benefits against potential risks.
• Evaluate for hypersensitivity: discontinue if rash or angioedema develops.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Pregabalin can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Opioids: combined use may increase risk of respiratory depression and profound sedation.
• Central nervous system depressants (e.g., benzodiazepines, alcohol): may enhance sedative effects and impair cognition.

Moderate Interactions (Monitor Closely)

• Antacids containing aluminum or magnesium: may reduce pregabalin absorption; separate dosing by at least 2 hours.
• Diuretics: can raise serum pregabalin concentrations, requiring monitoring for side effects.
• NSAIDs: may potentiate peripheral edema; observe for swelling.