Levetiracetam

Levetiracetam (中文: 左乙拉西坦)is an anticonvulsant medication used to treat epilepsy. It is taken either by mouth as an immediate or extended release formulation or by injection into a vein.

Drug Names

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Levetiracetam tablet 500mg	LEVE01	P1S1S3
Levetriacetam infusion 100mg/ml 5 ml	LEVE05

Mechanism of Action

Anticonvulsant medication. It inhibits presynaptic calcium channels, reducing neurotransmitter release. This is believed to impede impulse conduction across synapses.

Dosage

Monotherapy of focal seizures	By mouth, or by intravenous infusion ADULT and CHILD over 16 years: Initially 250 mg once daily increased after 1-2 weeks to 250 mg twice daily; thereafter Increased according to response in steps of 250 mg twice daily every 2 weeks Max. 1.5 g twice daily
Adjunctive therapy of focal seizures	By mouth CHILD 1-5 months Initially 7 mg/kg once daily, then Increased in steps of up to 7 mg/kg twice daily every 2 weeks Max. per dose 21 mg/kg twice daily CHILD 6 months – 17 years (body-weight up to 50 kg): Initially 10 mg/kg once daily, then Increased in steps of up to 10 mg/kg twice daily every 2 weeks Max. per dose 30 mg/kg twice daily CHILD 12-17 years (body-weight 50 kg and above): Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily every 2-4 weeks Max. per dose 1.5 g twice daily ADULT: Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily increased every 2-4 weeks Max. per dose 1.5 g twice daily By intravenous infusion CHILD 4-17 years (body-weight up to 50 kg): Initially 10 mg.kg once daily, then increased in steps of up to 10 mg/kg twice daily every 2 weeks Max. per dose 30 mg/kg twice daily CHILD 12-17 years (body-weight 50 kg and above): Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily every 2 weeks Max. per dose 1.5 g twice daily ADULT: Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily every 2-4 weeks Max. per dose 1.5 g twice daily
Adjunctive therapy of myoclonic seizures and tonic-clonic seizures	By mouth, or by intravenous infusion CHILD 12-17 years (body-weight up to 50 kg): Initially 10 mg/kg once daily, then Increased in steps of up to 10 mg/kg twice daily every 2 weeks Max. per dose 30 mg/kg twice daily CHILD 12-17 years (body-weight 50 kg or above): Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily every 2 weeks Max. per dose 1.5 g twice daily ADULT: Initially 250 mg twice daily, then Increased in steps of 500 mg twice daily every 2-4 weeks Max. per dose 1.5 g twice daily

A modified-release preparation is available for once-daily dosing as an adjunct in the treatment of focal seizures in patients aged 16 years and over. As with other antiepileptics, withdrawal of levetiracetam therapy or transition to or from another type of antiepileptic therapy should be made gradually to avoid precipitating an increase in the frequency of seizures. It is recommended:

• Those weighing more than 50 kg, the dose reduction of 1 g every 2 to 4 weeks;
• Those weighing less than 50 kg, the dose reduction should not exceed 20 mg/kg every 2 weeks.

Adverse drug reactions associated with the use of levetiracetam include:

Very common (>10% incidence)	*Dizziness drowsiness weakness somnolence
Common (1-10% incidence)	*Ataxia Gl effects include abdominal pain, anorexia, diarrhoea, dyspepsia, nausea, vomiting Insomnia Irritability tremor
Rare (<0.1% of incidence)	Agrtanulocytosis, causing increased vulmerability to infection. Choreoathetosis Hepatitis, hepatic failure Hyponatraemia Pancreatitis Stevens-Johnson syndrome Toxic epidermal necrosis

In a study, the incidence of decreased bone mineral density of patients on levetiracetam was significantly higher than those for other epileptic medications.