What Is Felbamate? Uses, Dosage, and What You Need to Know in 2026

Felbamate is an antiepileptic medication with a complicated history. It was approved by the FDA in 1993 with high hopes—and quickly became one of the most restricted medications in epilepsy treatment after serious adverse events emerged. Today, it remains a valuable drug for a small number of patients with severe, treatment-resistant epilepsy, but it comes with significant monitoring requirements and life-threatening risks that every patient must understand before taking it.

What Is Felbamate?

Felbamate (brand name: Felbatol) is a carbamate anticonvulsant. Its chemical name is 2-phenyl-1,3-propanediol dicarbamate. It is structurally related to but pharmacologically distinct from meprobamate, an older anxiolytic agent. Felbamate was first synthesized in the 1950s, but its anticonvulsant properties were discovered in the 1980s, leading to FDA approval in 1993.

It is not a controlled substance (it has no DEA schedule). However, due to its black box warnings for aplastic anemia and liver failure, it requires written informed consent before prescribing—a regulatory requirement not shared by most other antiepileptic drugs.

What Is Felbamate Used For?

Felbamate has two FDA-approved indications:

Partial seizures in adults and adolescents ≥14 years: Approved for use alone (monotherapy) or in combination with other antiepileptic drugs, but only after other safer treatments have failed. Covers partial seizures with or without secondary generalization.

Lennox-Gastaut syndrome (LGS) in children 2–14 years: Approved as adjunctive (add-on) therapy for partial and generalized seizures in this severe childhood epilepsy syndrome. The FDA designated this an orphan drug use.

Off-label, felbamate is also used in drug-resistant genetic generalized epilepsy (GGE), where a 2025 meta-analysis found a 65% response rate and 17% seizure freedom rate.

Critically, felbamate is not a first-line treatment for any of these conditions. It is specifically approved only for patients whose seizures cannot be controlled with safer medications. The FDA indication explicitly states it should not be used until the prescriber and patient agree that the benefits justify the serious risks.

Dosage Forms and Strengths

Felbamate is available in three forms:

400 mg tablets (yellow, scored, capsule-shaped)

600 mg tablets (peach-colored, scored, capsule-shaped)

600 mg/5 mL oral suspension (peach-colored liquid; shake well before each use; available in 8 oz and 32 oz bottles)

Typical Dosing for Adults

Felbamate is taken 3–4 times daily. Doses are gradually increased over several weeks. Here are the typical dosing ranges:

Starting dose: 1,200 mg/day in 3–4 divided doses

Week 2: Increase to 2,400 mg/day while reducing other concurrent AEDs by ~33%

Week 3 onward: Increase to 3,600 mg/day if needed; most clinical trials used 3,600 mg/day as the maintenance dose

When adding felbamate to existing antiepileptic drugs, the doses of those other drugs typically need to be reduced by 20–33% to prevent toxicity from drug interactions. Your neurologist will manage these adjustments. For children with LGS, dosing is weight-based, typically starting at 15 mg/kg/day and titrating up to 45 mg/kg/day.

How to Take Felbamate

Tablets can be taken with or without food. Taking with food may reduce nausea.

For the oral suspension: shake the bottle well before each dose; use a calibrated oral syringe or measuring device—not a household spoon.

Never stop taking felbamate suddenly. Always talk to your neurologist before making any changes to your dosage.

Store at room temperature (68–77°F / 20–25°C), away from moisture and light.

Who Should Not Take Felbamate?

Felbamate is contraindicated in patients with:

Any history of blood dyscrasia (blood cell disorders)

Any history of or current hepatic (liver) dysfunction

Known hypersensitivity to felbamate, other carbamates, or any ingredient in the formulation

For a deeper dive into how felbamate works in the brain, see our companion article How Does Felbamate Work? Mechanism of Action Explained in Plain English. And if you're having trouble finding felbamate at a pharmacy near you, medfinder can help you locate it.