Nepilex (Lacosamide)

Lacosamide is an anticonvulsant that acts on neuronal sodium channels to control seizure activity.

• Partial‑onset seizures: reduces the frequency of focal seizures with or without secondary generalisation.
• Epilepsy adjunct therapy: used as add‑on treatment when seizures are not controlled by other antiepileptic drugs.
• Refractory focal epilepsy: provides additional seizure control in patients who have not responded adequately to standard therapy.

• Lacosamide enhances the slow inactivation of voltage‑gated sodium channels, stabilising neuronal membranes and decreasing hyper‑excitability. By selectively targeting the slow inactivation phase, it reduces repetitive neuronal firing without affecting normal rapid channel activity, thereby limiting seizure propagation in the central nervous system.

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

Common Side Effects

• Dizziness: sensation of light‑headedness or unsteadiness.
• Fatigue: persistent tiredness or lack of energy.
• Nausea: feeling of stomach upset often accompanied by vomiting.
• Headache: mild to moderate pain in the head region.
• Blurred vision: temporary loss of visual clarity.
• Diplopia: double‑vision episodes.

Serious or Rare Side Effects

• Suicidal thoughts or behavior: emergence of depressive or self‑harm ideation.
• Cardiac conduction abnormalities: PR‑interval prolongation that may lead to arrhythmia.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Hepatic dysfunction: elevated liver enzymes indicating possible liver injury.
• Anaphylaxis: acute allergic reaction with airway compromise.

Before initiating lacosamide therapy, several safety considerations should be addressed.

• Cardiac assessment: obtain baseline ECG to detect PR‑interval prolongation.
• Psychiatric monitoring: watch for new or worsening depression or suicidal ideation.
• Renal function: adjust dose in patients with moderate to severe renal impairment.
• Hepatic function: use caution and consider dose modification in liver disease.
• Discontinuation: avoid abrupt cessation to prevent seizure rebound.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and direct sunlight.

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

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole): may increase lacosamide plasma concentrations.
• Drugs that prolong PR interval (e.g., quinidine, class IA antiarrhythmics): additive cardiac conduction effects.

Moderate Interactions (Monitor Closely)

• Other antiepileptics (e.g., carbamazepine, phenytoin): may affect serum levels of each agent.
• Alcohol: can enhance central nervous system depression and dizziness.
• Hormonal contraceptives: lacosamide may reduce contraceptive effectiveness, requiring additional barrier methods.