Two medicines, side by side
Zonisamide vs gabapentin
Zonisamide and gabapentin are both labeled for seizures and epilepsy. Drugs@FDA records approvals of zonisamide since 2000 and of gabapentin since 1993. Pharmacies paid $0.106 per zonisamide 100 mg capsule and $0.0218 per gabapentin 100 mg capsule (NADAC, October 7, 2026). Zonisamide's other strengths are brand-only: $2.75 per mL (Zonisade 100 mg/5 mL oral suspension).
Check it at the source: the zonisamide FDA label on DailyMed (effective June 4, 2026); the gabapentin FDA label on DailyMed (effective May 12, 2026).
Highlights of the zonisamide record
Zonisamide (Zonegran) · label of June 4, 2026
Used for
From the label: indicationsZonisamide is indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.
On the market
- Earliest approval on file
- March 27, 2000
- Generic labelers
- 20 labelers
- Pharmacy cost
- $0.106 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 11
Highlights of the gabapentin record
Gabapentin (Neurontin) · label of May 12, 2026
Used for
From the label: indicationsNEURONTIN ® is indicated for: • Management of postherpetic neuralgia in adults • Adjunctive therapy in the treatment of partial onset seizures, with and without secondary generalization, in adults and pediatric patients 3 years and older with epilepsy NEURONTIN is indicated for: • Postherpetic neuralgia in adults ( 1 ) • Adjunctive therapy in the treatment of partial onset seizures, with and without secondary generalization, in adults and pediatric patients 3 years and older with epilepsy […]
On the market
- Earliest approval on file
- December 30, 1993
- Generic labelers
- 85 labelers
- Pharmacy cost
- $0.0218 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 22
Source: FDA drug labels via openFDA (Zonisamide label of June 4, 2026, Gabapentin label of May 12, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do zonisamide and gabapentin differ on the record?
Both are in FDA's class anti-epileptic agents.
Half-life, in each label's words: Zonisamide, “The elimination half-life of zonisamide in plasma is approximately 63 hours.”; Gabapentin, “Gabapentin elimination half-life is 5 to 7 hours and is unaltered by dose or following multiple dosing.”
Generics: zonisamide since 2005; gabapentin since 2003 (Drugs@FDA).
| Zonisamide | Gabapentin | |
|---|---|---|
| Labeled for | Seizures and epilepsy | Nerve pain and fibromyalgia, Seizures and epilepsy |
| Pharmacologic class | Anti-epileptic Agent | Anti-epileptic Agent |
| How it works (label) | n/a | The precise mechanisms by which gabapentin produces its analgesic and antiepileptic actions are unknown. |
| Half-life (label) | The elimination half-life of zonisamide in plasma is approximately 63 hours. | Gabapentin elimination half-life is 5 to 7 hours and is unaltered by dose or following multiple dosing. |
| Earliest approval on file (Drugs@FDA) | March 27, 2000 | December 30, 1993 |
| First generic approved | December 22, 2005 | September 12, 2003 |
| Generic labelers (NDC) | 20 labelers | 85 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.106 per capsule (Zonisamide 100 mg capsule) | $0.0218 per capsule (Gabapentin 100 mg capsule) |
| 12-month price change | -1% | +0.9% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 11 | 22 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 10,560 | 362,654 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to zonisamide
- every medicine labeled for the same conditions