Lacosamide

Usage

  • Lacosamide is used to treat partial seizures in children aged 4-16 years. It is also used in the treatment of primary generalised seizures with idiopathic generalised epilepsy aged 4 years and older. 
  • The PBS indication is for intractable partial seizures not controlled by other anti-convulsants, including first-line medications, in children aged 4-16 years. The PBS indication for primary generalised tonic-clonic seizures in patients with idiopathic generalised epilepsy is as add-on therapy for children aged 4 years and older. In both PBS indications there are treatment criteria that must be met (see PBS link below).
  • Its mechanism of action is slow inactivation of voltage gated sodium channels.
  • It does not have significant drug interactions and has a relatively good safety profile.


Therapeutic Indications (from: Australian Product Information Sheets - MIMS)

Vimpat (lacosamide) tablets and oral solution are indicated as:

  • monotherapy in the treatment of partial-onset seizures with or without secondary generalisation in patients with epilepsy aged 16 years and older;
  • add-on therapy in the treatment of partial-onset seizures with or without secondary generalisation in patients with epilepsy aged 4 years and older;
  • add-on therapy in the treatment of primary generalised tonic-clonic seizures in patients with idiopathic generalised epilepsy aged 4 years and older.

Resources

Side effects

Common side effects

  • Dizziness, blurred vision, drowsiness.

Other notable side effects

  • Less commonly: irritability, tics, mood change, depression, palpitations, irregular heartbeat, nausea, vomiting and cognitive difficulties.
  • Rarely: Hypersensitivity syndrome, facial oedema.
  • All anticonvulsants are potentially teratogenic and this is often dose related (see section: AED Prescribing - Pregnancy)
  • For a complete list of adverse effects, appropriate formularies should be consulted.

Dosing

  • Initial dosage as adjunctive therapy if child is < 30kgs: 0.5 – 1mg/kg/day for one week and increase weekly/fortnightly by 1mg/kg/day to 2 – 6 mg/kg/day, in 2 divided doses.
  • For adjunctive treatment in a child 30-50kgs: a common recommended maintenance dose is 4mg/kg/day, in 2 divided doses.
  • A recommended maintenance dose for adults is 200 to 400 mg/day based on efficacy and tolerability.
  • Oral Lacosamide may be taken with or without food.
  • There is an intravenous preparation. Lacosamide can be used in status epilepsy. For information on intravenous use, consult appropriate formularies and product information.
  • Dosages per kilogram can only be used in children of weight approximately up to 30-35kgs.
  • Consult appropriate formularies for children with higher weights and in the adult range.
  • These dosages are only a guide and appropriate formularies should be consulted as needed and tailored to the patient by the primary physician.

Preparations:

Tablets

  • 50 mg (pink)
  • 100 mg (dark yellow)
  • 150 mg (salmon)
  • 200 mg (blue) film-coated

Syrup

  • 10mg/ 1 ml oral solution

Intravenous

  • 200mg/20mls

Interactions | Precautions

Precautions

  • Hepatic impairment: Lacosamide’s use is not recommended in patients with severe hepatic impairment.
  • Patients with hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 may have a significant increase in exposure to Lacosamide.
  • Dose reduction may be necessary in these patients. 

Weaning

  • When ceasing Lacosamide it is important to withdraw slowly (over a minimum of 1 week) to minimize the potential of increased seizure frequency in patients with seizure disorders.

Cardiac

  • Lacosamide may cause prolongation of the PR interval, this is dose related, so monitoring of PR interval may be necessary.
  • Other sodium channel drugs should be avoided e.g. carbamazepine or dilantin.
  • There must be caution if there is a history of cardiac disease or conduction problems.

Pregnancy

  • Usage in pregnancy needs to be discussed with a neurologist.
  • There is limited data on Lacosamide in pregnancy; theoretically it may interfere with CNS development of the foetus.
  • See section: AED Prescribing - Pregnancy