Levetiracetam (S-Etiracetam)

Levetiracetam (S-Etiracetam) In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• The mechanism of anticonvulsant action is unknown but it has been shown to bind to the pre-synaptic vesicle protein SV2A within the brain, modulating the release of neurotransmitters, which may protect against seizures.

Uses of Levetiracetam (S-Etiracetam)

• As an adjunctive maintenance therapy in dogs and cats for the management of epileptic seizures refractory to conventional therapy.
• Also as a primary therapy where phenobarbital is contraindicated; however, efficacy is significantly worse than phenobarbital in newly diagnosed epileptic dogs.
• Used at a higher dose, in addition to conventional maintenance therapy, as pulse therapy for cluster seizures.
• A constant intravenous infusion can be used for emergency control of status epilepticus.

Dose of Levetiracetam (S-Etiracetam) in Dogs and Cats

Dogs, Cats:

• Maintenance therapy (as adjunct or sole anticonvulsant): 20–30 mg/kg p.o. q8–12h.
• Pulse therapy for severe cluster seizures (in addition to maintenance therapy): 30 mg/kg p.o. q6–8h for the duration of the cluster (usually for 2–3 days) and then incrementally reduced and stopped until the start of the next cluster.
• Status epilepticus: 60 mg/kg i.v. bolus q8h or continuous intravenous infusion of 8 mg/kg/h, incrementally increased to effect if required.
• The parenteral preparation can be given at 40 mg/kg per rectum if oral or i.v. administration is not possible.

Side Effects of Levetiracetam (S-Etiracetam) in Dogs and Cats

• Sedation and ataxia in dogs.
• Reduced appetite, hypersalivation and lethargy in cats.

Contraindications of Levetiracetam (S-Etiracetam) in Dogs and Cats

• Severe renal disease.

Some Notes:

• There is some evidence to suggest that phenobarbital increases levetiracetam clearance, reducing the half-life and peak levels.
• Levetiracetam is rapidly absorbed from the GI tract with peak plasma concentrations reached in <2 hours of oral dosing.
• Steady-state is rapidly achieved within 2 days.
• Plasma protein binding is minimal.
• The plasma half-life is around 3–4 hours in dogs.
• It will also reach target serum concentrations if administered rectally.
• Withdrawal of levetiracetam therapy or transition to or from another type of antiepileptic therapy should be done gradually.
• Use with caution and in reduced doses in patients with renal impairment; in humans, renal elimination of levetiracetam correlates with creatinine clearance.