THERAPEUTICS

Brands

• Zonegran

Generic?

• Yes

Class

• Antiepileptic drug (AED), structurally a sulfonamide

Commonly Prescribed for

(FDA approved in bold)

• Partial-onset seizures (adjunctive in adults)

• Partial-onset seizures (adjunctive in pediatric patients)

• Primary generalized tonic-clonic seizures (adjunctive; adults and pediatric patients age 2–16)

• Myoclonic epilepsy, Lennox-Gastaut syndrome, absence seizure

• Infantile spasms (West syndrome)

• Idiopathic intracranial hypertension

• Migraine prophylaxis

• Adjunct to levodopa for Parkinson's disease

• Obesity

• Binge-eating disorder/bulimia

• Tardive dyskinesias

• Neuropathic pain

How the Drug Works

Unknown but there are multiple mechanisms of action that may be important

• Sodium channel antagonist

• Modulates N-, P-, and T-type calcium channels

• Binds to GABA receptors

• Weak carbonic anhydrase inhibitor

• Monoamine oxidase (MAO)-B inhibition

• May help facilitate dopamine and serotonin neurotransmission

How Long Until It Works

• Seizures: by 2–3 weeks

• Migraines: can take up to 3 months on a stable dose to see full effect

If It Works

• Seizures: goal is the remission of seizures. Continue as long as effective and well tolerated. Consider tapering and slowly stopping after 2 years seizure-free, depending on the type of epilepsy

• Migraine: goal is a 50% or greater reduction in migraine frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if patient considering pregnancy

If It Doesn't Work

• Increase to highest tolerated dose

• Epilepsy: consider changing to another agent, adding a second agent, using a medical device, or a referral for epilepsy surgery evaluation. When adding a second agent, keep drug interactions in mind

• Migraine: address other issues such as medication overuse, other coexisting medical disorders, such as anxiety, and consider changing to another agent or adding a second agent

Best Augmenting Combos for Partial Response or Treatment-Resistance

• For some patients with epilepsy or migraine, low-dose polytherapy with 2 or more drugs may be better tolerated and more effective than high-dose monotherapy

• Epilepsy: keep in mind drug interactions and their effect on levels

• Migraine: consider β-blockers, antidepressants, natural products, other AEDs, and non-medication treatments, such as biofeedback, to improve headache control