Medicines labeled for the same conditions
Alternatives to methsuximide
20 other medicines are given the same way (oral) and in the same FDA class as methsuximide or labeled mainly for the same use (seizures and epilepsy); 11 are in its class, anti-epileptic agents: gabapentin, lamotrigine, divalproex, oxcarbazepine and 7 more; the others include 1 benzodiazepine and 1 noncompetitive ampa glutamate receptor antagonist (FDA labels read October 8, 2026). In the same class, the lowest pharmacy cost is $0.0218 per gabapentin 100 mg capsule (what pharmacies paid in the NADAC survey; strengths differ).
Which medicines are labeled for the same conditions as methsuximide?
Seizures and epilepsy lists all 27 medicines labeled for it, by any route. Each row shows the conditions both labels name. They are listed as public records, not as substitutes: whether one can replace another depends on the person and is a prescriber's decision.
| Medicine and FDA class | Shared indication | Generic labelers (oral) | Pharmacy cost | Boxed warning | Shortage |
|---|---|---|---|---|---|
| Methsuximideanti-epileptic agent | this medicine | 1 labeler | $4.40 per capsule 300 mg capsule | No | No current entry |
| Gabapentinanti-epileptic agent · same class | Seizures and epilepsy | 87 labelers | $0.0218 per capsule 100 mg capsule | No | No current entry |
| Lamotriginemood stabilizer · same class | Seizures and epilepsy | 50 labelers | $0.0268 per tablet 25 mg tablet | Yes | A presentation being discontinued |
| Divalproexmood stabilizer · same class | Seizures and epilepsy | 44 labelers | $0.194 per tablet 500 mg tablet | Yes | No current entry |
| Oxcarbazepineanti-epileptic agent · same class | Seizures and epilepsy | 43 labelers | $0.167 per tablet 300 mg tablet | No | No current entry |
| Zonisamideanti-epileptic agent · same class | Seizures and epilepsy | 20 labelers | $0.106 per capsule 100 mg capsule | No | No current entry |
| Valproic acidmood stabilizer · same class | Seizures and epilepsy | 19 labelers | $0.243 per capsule 250 mg capsule | Yes | Listed; available |
| Phenytoinanti-epileptic agent · same class | Seizures and epilepsy | 23 labelers | $0.145 per capsule 100 mg capsule | No | No current entry |
| Primidoneanti-epileptic agent · same class | Seizures and epilepsy | 21 labelers | $0.0914 per tablet 50 mg tablet | No | No current entry |
| Felbamateanti-epileptic agent · same class | Seizures and epilepsy | 9 labelers | $1.00 per tablet 600 mg tablet | Yes | No current entry |
| Ethosuximideanti-epileptic agent · same class | Seizures and epilepsy | 9 labelers | $0.243 per capsule 250 mg capsule | No | No current entry |
| Tiagabineanti-epileptic agent · same class | Seizures and epilepsy | 2 labelers | $2.62 per tablet 2 mg tablet | No | A presentation being discontinued |
| Topiramate | Seizures and epilepsy | 47 labelers | $0.0567 per tablet 100 mg tablet | No | No current entry |
| Levetiracetam | Seizures and epilepsy | 63 labelers | $0.0736 per tablet 500 mg tablet | No | No current entry |
| Phenobarbital | Seizures and epilepsy | none listed | $0.213 per tablet 100 mg tablet | No | A presentation being discontinued |
| Clonazepambenzodiazepine | Seizures and epilepsy | 31 labelers | $0.0244 per tablet 1 mg tablet | Yes | In shortage |
| Lacosamide | Seizures and epilepsy | 43 labelers | $0.174 per tablet 100 mg tablet | No | No current entry |
| Brivaracetam | Seizures and epilepsy | 14 labelers | $0.259 per tablet 100 mg tablet | No | No current entry |
| Eslicarbazepine | Seizures and epilepsy | 9 labelers | $1.68 per tablet 200 mg tablet | No | No current entry |
| Perampanelnoncompetitive ampa glutamate receptor antagonist | Seizures and epilepsy | 3 labelers | $14.43 per tablet 4 mg tablet | Yes | No current entry |
| Cenobamate | Seizures and epilepsy | none listed | $39.87 per tablet 100 mg tablet | No | No current entry |
Source: FDA drug labels (indications) via openFDA; FDA NDC Directory; CMS NADAC of October 7, 2026; FDA Drug Shortage Database (FDA files October 8, 2026)
What do pharmacies pay for each?
The headline NADAC price per unit of each medicine's most widely listed form; strengths differ, so compare like with like on each record.
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
What next?
- Methsuximide: the full record
- label, generics, price, shortages, recalls