Simple Partial Seizures Medication

Many anticonvulsants currently are approved by the US Food and Drug Administration (FDA) for partial seizures with and without secondary generalization. These drugs have approval for treatment of single partial seizures (SPS) as well. No single agent is the drug of choice for SPS.

Also see Antiepileptic Drugs.

Class Summary

These agents prevent seizure recurrence and terminate clinical and electrical seizure activity.

Ezogabine (Potiga)

Neuronal potassium channel opener. Stabilizes neuronal KCNQ (Kv7) channels in the open position, increasing the stabilizing membrane current and preventing bursts of action potentials during the sustained depolarizations associated with seizures. Indicated as adjunctive therapy in partial-onset seizures uncontrolled by current medications.

Carbamazepine (Tegretol, Tegretol-XR, Carbatrol, Epitol)

Carbamazepine is a tricyclic compound extensively metabolized to its active metabolite, carbamazepine-epoxide. This agent markedly induces its own metabolism and is highly bound to plasma proteins. Carbamazepine is available as 100-mg/mL suspension; 100-mg chewable tablet; 200-mg tablet; 100-, 200-, and 400-mg delayed-release tablets (Tegretol-XR); and 200- and 300-mg extended-release capsules (Carbatrol).

Divalproex sodium (Depacon, Depakene, Depakote, Depakote-ER)

This is a branched-chain fatty acid that undergoes oxidative metabolism and is highly protein bound. The amount of protein binding increases with dose. This agent is available as 250-mg/5 mL syrup; 250-mg capsules; 125-mg sprinkle capsules; 125-, 250-, and 500-mg delayed-release tablets; 250- and 500-mg extended-release tablets; and 100-mg/mL injectable solution.

Gabapentin (Neurontin)

Gabapentin has saturable gastric absorption with virtually no protein binding and no metabolism; excretion is primarily renal. This agent is available as 100-, 300-, and 400-mg capsules; 600- and 800-mg tablets; and 50-mg/mL solution.

Lamotrigine (Lamictal)

Lamotrigine is hepatically metabolized and moderately protein bound. Its half-life is shorter -life in the presence of enzyme-inducing compounds. It is available as 2-, 5-, and 25-mg dispersible tablets and 25-, 100-, 150-, and 200-mg tablets.

Phenytoin (Dilantin, Phenytek)/ Fosphenytoin (Cerebyx)

Phenytoin is a poorly soluble compound that is highly protein bound, metabolized by cytochrome P-450 system, and has nonlinear pharmacokinetics. It is available as a 125-mg/5 mL suspension; 50-mg chewable tablet; 30-mg capsules; 100-mg capsules; and 50-mg/mL injectable phenytoin solution (contains propylene glycol). Fosphenytoin is phosphorylated phenytoin, a prodrug that is highly soluble and converted rapidly to phenytoin; it contains 50 mg phenytoin equivalent per mL solution.

Primidone (Mysoline)

Primidone is metabolized to phenobarbital and phenylethylmalonamide (PEMA), which also possesses some weak anticonvulsant activity. It is available as a 250-mg/5 mL suspension and 50- and 250-mg tablets.

Tiagabine (Gabitril)

Tiagabine is a gamma-aminobutyric acid (GABA) reuptake inhibitor, with its metabolism enhanced by cytochrome P-450 inducers. It is highly protein bound. It is available as a 2-, 4-, 12-, and 16-mg tablets.

Topiramate (Topamax)

Topiramate undergoes moderate hepatic metabolism and is excreted largely by the kidneys. It has low protein binding. It is available as 15- and 25-mg sprinkle capsules and as 25-, 100-, and 200-mg tablets.

Oxcarbazepine (Trileptal)

The pharmacological activity of oxcarbazepine is primarily performed by the drug's 10-monohydroxy metabolite (MHD). Oxcarbazepine may block voltage-sensitive sodium channels, inhibit repetitive neuronal firing, and impair synaptic impulse propagation. An anticonvulsant effect may also occur by affecting potassium conductance and high-voltage activated calcium channels.

Drug pharmacokinetics are similar in older children (>8 y) and adults. Young children (< 8 y) have a 30-40% increased clearance compared with older children and adults. Oxcarbazepine is available as 150-, 300-, and 600-mg tablets and 300-mg/5 mL solution.

Levetiracetam (Keppra)

The mechanism of action of levetiracetam is unknown. This agent is approved for adjunctive use in partial epilepsy. It is available as 250-, 500-, 750-, and 1000-mg tablets and 100-mg/mL solution.

Zonisamide (Zonegran)

Zonisamide is indicated for adjunctive treatment of partial seizures with or without secondary generalization. It is available as 25-, 50-, and 100-mg sprinkle capsules. Evidence suggests that it is also effective in myoclonic and other generalized seizure types.

Pregabalin (Lyrica)

A structural derivative of GABA, pregabalin has an unknown mechanism of action. It binds with high affinity to alpha2-delta site (a calcium channel subunit). In vitro, pregabalin reduces calcium-dependent release of several neurotransmitters, possibly by modulating calcium channel function. It is FDA approved for neuropathic pain associated with diabetic peripheral neuropathy or postherpetic neuralgia and as adjunctive therapy in partial-onset seizures. It is available as 25-, 50-, 75-, 100-, 150-, 200-, 225-, and 300-mg capsules.

Lacosamide (Vimpat)

Lacosamide selectively enhances slow inactivation of voltage-gated sodium channels, resulting in stabilization of hyperexcitable neuronal membranes and inhibition of repetitive neuronal firing. It is indicated for adjunctive therapy of partial-onset seizures.

Ethotoin (Peganone)

Ethotoin may act in the motor cortex, where it may inhibit the spread of seizure activity. The activity of brain stem centers responsible for the tonic phase of grand mal seizures may also be inhibited.