Core pharmacology

Class Group

Anticonvulsant

Legacy Cicm Level

Level 3

Indications Uses

Epilepsy in the case of partial seizures
Adjunctive therapy for partial, myoclonic and tonic-clonic seizures

Chemical Pharmaceutics

# Pyrrolidine
# Highly lipid soluble

Presentation

# Steady state after two days of a twice
daily administration schedule.
# Dose: PO/IV 1000 mg daily given as
500 mg 2 times a day

Mechanism of action

1. Partial inhibition of N-type Ca2+ currents and reduced release of Ca2+ from intra-neuronal stores causing
reduced intra-neuronal Ca.
2. Inhibition of synaptic vesicle protein 2A (SV2A) involved in vesicle fusion and neurotransmitter exocytosis
# → membrane hyperpolarisation → ↓NT release.

Absorption

IV, PO Rapidly abs- BA 100%.

Protein binding

<10% protein bound

Metabolism

# Enzymatic hydrolysis (24%) in a large number of tissues including whole blood but not plasma.

Excretion

# 95% excreted in the urine
# 65% unchanged

Half-life

T1/2 7hrs