FDA pharmacologic class
Anti-seizure medicines
14 medicines are in FDA's class of anti-epileptic agents (anti-seizure medicines): gabapentin (Neurontin), lamotrigine (Lamictal), divalproex (Depakote), oxcarbazepine (Trileptal), phenytoin (Dilantin), valproic acid, zonisamide (Zonegran), primidone (Mysoline) and 6 more. All 14 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is gabapentin 100 mg capsule at $0.0218 per capsule (NADAC).
Which medicines are anti-seizure medicines?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Gabapentin | Neurontin, Gralise, Relgaabi | 85 labelers | $0.0218 per capsule 100 mg capsule | No | No current entry | 22 |
| Lamotrigine | Lamictal, Subvenite | 49 labelers | $0.0268 per tablet 25 mg tablet | Yes | A presentation being discontinued | 10 |
| Divalproex | Depakote | 44 labelers | $0.194 per tablet 500 mg tablet | Yes | No current entry | 16 |
| Oxcarbazepine | Trileptal, Oxtellar | 43 labelers | $0.167 per tablet 300 mg tablet | No | No current entry | 6 |
| Phenytoin | Dilantin, Phenytek | 29 labelers | $0.145 per capsule 100 mg capsule | No | No current entry | 11 |
| Valproic acid | none listed | 22 labelers | $0.243 per capsule 250 mg capsule | Yes | Listed; available | 2 |
| Zonisamide | Zonegran | 20 labelers | $0.106 per capsule 100 mg capsule | No | No current entry | 11 |
| Primidone | Mysoline | 21 labelers | $0.0914 per tablet 50 mg tablet | No | No current entry | 6 |
| Vigabatrin | Sabril, Vigafyde, Vigadrone | 15 labelers | n/a | Yes | A presentation being discontinued | 3 |
| Felbamate | Felbatol | 9 labelers | $1.00 per tablet 600 mg tablet | Yes | No current entry | 0 |
| Fosphenytoin | Cerebyx | 7 labelers | n/a | Yes | No current entry | 6 |
| Ethosuximide | Zarontin | 9 labelers | $0.243 per capsule 250 mg capsule | No | No current entry | 4 |
| Tiagabine | none listed | 2 labelers | $2.62 per tablet 2 mg tablet | No | A presentation being discontinued | 1 |
| Methsuximide | Celontin | 1 labeler | $4.40 per capsule 300 mg capsule | No | No current entry | 0 |
Source: FDA Established Pharmacologic Class (NDC Directory, openFDA); CMS NADAC of October 7, 2026; FDA shortages and recalls (FDA files October 8, 2026)
What do pharmacies pay?
Each medicine's most widely listed form, per unit, in the NADAC survey: what pharmacies paid, not what a patient pays; strengths differ, so compare like with like.
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price