Two medicines, side by side
Divalproex vs lamotrigine
Divalproex and lamotrigine are both labeled for bipolar disorder and seizures and epilepsy. Drugs@FDA records approvals of divalproex since 1983 and of lamotrigine since 1994. Pharmacies paid $0.194 per divalproex sod ER 500 mg tablet and $0.0268 per lamotrigine 25 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Lamotrigine's other strengths are brand-only: $2.86 per mL (Subvenite 10 mg/mL suspension). How each works, in its label's words: Divalproex, “Divalproex sodium dissociates to the valproate ion in the gastrointestinal tract.”; Lamotrigine, “The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown.”
Check it at the source: the divalproex FDA label on DailyMed (effective March 31, 2026); the lamotrigine FDA label on DailyMed (effective October 10, 2025).
Highlights of the divalproex record
Divalproex (Depakote) · label of March 31, 2026
LIFE THREATENING ADVERSE REACTIONS Hepatotoxicity General Population: Hepatic failure resulting in fatalities has occurred in patients receiving valproate and its derivatives. These incidents usually have occurred during the first six months of treatment. Serious or fatal hepatotoxicity may be preceded by non-specific symptoms such as malaise, weakness, lethargy, facial edema, anorexia, and vomiting. In patients with epilepsy, a loss of seizure control may also occur.
Used for
From the label: indicationsDepakote is an anti-epileptic drug indicated for: Treatment of manic episodes associated with bipolar disorder ( 1.1 ) Monotherapy and adjunctive therapy of complex partial seizures and simple and complex absence seizures; adjunctive therapy in patients with multiple seizure types that include absence seizures ( 1.2 ) Prophylaxis of migraine headaches ( 1.3 ) 1.1 Mania Depakote (divalproex sodium) is a valproate and is indicated for the treatment of the manic episodes associated with bipolar disorder. […]
On the market
- Earliest approval on file
- March 10, 1983
- Generic labelers
- 44 labelers
- Pharmacy cost
- $0.194 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 16
Highlights of the lamotrigine record
Lamotrigine (Lamictal) · label of October 10, 2025
SERIOUS SKIN RASHES LAMICTAL can cause serious rashes requiring hospitalization and discontinuation of treatment. The incidence of these rashes, which have included Stevens-Johnson syndrome, is approximately 0.3% to 0.8% in pediatric patients (aged 2 to 17 years) and 0.08% to 0.3% in adults receiving LAMICTAL. One rash-related death was reported in a prospectively followed cohort of 1,983 pediatric patients (aged 2 to 16 years) with epilepsy taking LAMICTAL as adjunctive therapy.
Used for
From the label: indicationsLAMICTAL is indicated for: Epilepsy–adjunctive therapy in patients aged 2 years and older: • partial-onset seizures. • primary generalized tonic-clonic (PGTC) seizures. • generalized seizures of Lennox-Gastaut syndrome. […]
On the market
- Earliest approval on file
- December 27, 1994
- Generic labelers
- 49 labelers
- Pharmacy cost
- $0.0268 per tablet
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 10
Source: FDA drug labels via openFDA (Divalproex label of March 31, 2026, Lamotrigine label of October 10, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do divalproex and lamotrigine differ on the record?
How each works, in its label's words: Divalproex, “Divalproex sodium dissociates to the valproate ion in the gastrointestinal tract.”; Lamotrigine, “The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown.”
Both are in FDA's class mood stabilizers.
Both labels carry a boxed warning; the records quote them.
Generics: divalproex since 2008; lamotrigine since 2006 (Drugs@FDA).
| Divalproex | Lamotrigine | |
|---|---|---|
| Labeled for | Bipolar disorder, Migraine, Seizures and epilepsy | Seizures and epilepsy, Bipolar disorder |
| Pharmacologic class | Anti-epileptic Agent, Mood Stabilizer | Anti-epileptic Agent, Mood Stabilizer |
| How it works (label) | Divalproex sodium dissociates to the valproate ion in the gastrointestinal tract. The mechanisms by which valproate exerts its therapeutic effects have not been established. | The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown. |
| Half-life (label) | Mean terminal half-life for valproate monotherapy ranged from 9 to 16 hours following oral dosing regimens of 250 to 1,000 mg. | n/a |
| Earliest approval on file (Drugs@FDA) | March 10, 1983 | December 27, 1994 |
| First generic approved | July 29, 2008 | June 21, 2006 |
| Generic labelers (NDC) | 44 labelers | 49 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.194 per tablet (Divalproex sod ER 500 mg tablet) | $0.0268 per tablet (Lamotrigine 25 mg tablet) |
| 12-month price change | +3% | -12% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | A presentation being discontinued |
| Recalls recorded | 16 | 10 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 46,267 | 130,994 |
| 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)
Do their labels mention each other?
Divalproex label, warnings and precautionsThe largest of these studies 1 is a prospective cohort study conducted in the United States and United Kingdom that found that children with prenatal exposure to valproate (n=62) had lower IQ scores at age 6 (97 [95% CI 94-101]) than children with prenatal exposure to the other antiepileptic drug monotherapy treatments evaluated: lamotrigine (108 [95% CI 105–110]), carbamazepine (105 [95% CI 102–108]), and phenytoin …
Source: FDA drug labels via openFDA
What next?
- Alternatives to divalproex
- every medicine labeled for the same conditions