SV2A Ligand

Levetiracetam

An SV2A ligand used alone or as add-on for focal seizures, and as add-on for myoclonic and generalized tonic-clonic seizures.

Drug card

Class: SV2A ligand
How it works: Binding synaptic vesicle protein 2A to damp neurotransmitter release
Used for: Focal seizures, alone or as add-on treatment
Myoclonic seizures in juvenile myoclonic epilepsy
Primary generalized tonic-clonic seizures
Status epilepticus (intravenous)
Known for: Drowsiness and tiredness
Irritability, aggression and mood swings
Its name: -racetam means a piracetam-type drug (antiepileptic or nootropic)

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Mechanism of action

How does levetiracetam work?

Levetiracetam is a pyrrolidone derivative, chemically unrelated to older antiepileptics. It binds synaptic vesicle protein 2A and also partly inhibits N-type calcium currents and calcium release inside neurons. It is fully absorbed, less than 10% protein-bound and not metabolized by liver CYP enzymes; about two-thirds leaves unchanged in the urine.

Uses

What is levetiracetam used for?

Focal seizures, alone or as add-on treatment
Myoclonic seizures in juvenile myoclonic epilepsy
Primary generalized tonic-clonic seizures
Status epilepticus (intravenous)

Side effects

Side effects of levetiracetam

Drowsiness and tirednessKnown for
Irritability, aggression and mood swingsKnown for
Psychosis and abnormal behaviorSerious
Suicidal thoughtsSerious
Poor coordination and unsteadiness
Severe skin reactions (SJS, TEN)Serious
DRESS (multiorgan hypersensitivity)Serious
Anaphylaxis and angioedemaSerious
Low blood counts, rarely pancytopeniaSerious
Acute kidney injury (very rare)Serious
Pancreatitis (rare)Serious
Hepatitis and liver failure (rare)Serious

Known for marks what an exam expects you to know it for.

Watch for

Cautions and what sets it apart

Doses are reduced in kidney impairment, because clearance falls in step with creatinine clearance.
Behavioral effects such as aggression and irritability are commoner in children; watch all ages for depression and suicidal thoughts.
Withdraw gradually, since stopping suddenly can trigger seizures or status epilepticus.
Levels fall during pregnancy, most in the third trimester, so seizure control is watched closely.

Good to know: Interactions are few: it is not metabolized by liver CYP enzymes and binds little to plasma proteins. WHO lists an intravenous form for status epilepticus.

Remember it

A way to remember it

SV2A: the target is the Synaptic Vesicle.

SV2A stands for synaptic vesicle protein 2A. Levetiracetam and brivaracetam bind this vesicle protein, which helps nerve endings release neurotransmitter, rather than acting mainly on sodium channels as phenytoin and carbamazepine do.

Written for biofideX

Its name

-racetam means piracetam-type drug (antiepileptic or nootropic)
WHO defines it by piracetam, a nootropic, but levetiracetam and brivaracetam are antiepileptics that bind the synaptic vesicle protein SV2A.
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Its class

SV2A ligands

SV2A ligands bind synaptic vesicle protein 2A, a glycoprotein in the membrane of the vesicles that store neurotransmitter in nerve endings and help regulate its release. Binding seems to curb the excessive, synchronized firing that spreads a seizure while leaving normal transmission alone. The full mechanism is unknown, but how tightly a drug binds SV2A tracks its antiseizure strength in animal models.

Easily mixed up with sodium channel-blocking antiepileptics and gabapentinoids.

Sources

Checked against

Written for biofideX in plain words, after checking these references:

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.

Practice it

Epilepsy and nerve pain

Levetiracetam is one of 8 drugs practiced together here: their classes, how they work, what they treat and what they're known for.

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