What the FDA labels say about taking them together
Rufinamide and valproic acid
Valproic acid's FDA label of January 24, 2025 names rufinamide in its drug interactions section; rufinamide's label does not name valproic acid itself but warns about its class (Anti-seizure medicines). The valproic acid label: “… inhibiting their metabolism or protein binding displacement Patients stabilized on rufinamide should begin valproate therapy at a low dose, and titrate to clinically effective dose Dosage adjustment of …”
Check it at the source: the rufinamide FDA label on DailyMed (effective December 15, 2022, Eisai Inc.); the valproic acid FDA label on DailyMed (effective January 24, 2025, PAI Holdings, LLC dba PAI Pharma).
What does the rufinamide label say about valproic acid?
Rufinamide's label does not name valproic acid itself; it warns about its class (Anti-seizure medicines):
Rufinamide label, warnings and precautionsCaution should be used when administering BANZEL with other drugs that shorten the QT interval [ see Contraindications ( 4 ) ]. Multi-organ Hypersensitivity /Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multi-organ hypersensitivity, has been reported in patients taking antiepileptic drugs, including BANZEL.
Rufinamide label, warnings and precautionsBehavior and Ideation Antiepileptic drugs (AEDs), including BANZEL, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication.
Source: FDA drug label (Banzel), Eisai Inc., effective December 15, 2022 (SPL set 0a3fa925-1abd-458a-bd57-4ae780a1ef2d), via openFDA; the full label on DailyMed
What does the valproic acid label say about rufinamide?
Valproic acid label, drug interactionsMonitoring of valproate concentrations is recommended ( 7.1 ) Co-administration of valproate can affect the pharmacokinetics of other drugs (e.g., diazepam, ethosuximide, lamotrigine, phenytoin) by inhibiting their metabolism or protein binding displacement ( 7.2 ) Patients stabilized on rufinamide should begin valproate therapy at a low dose, and titrate to clinically effective dose ( 7.2 ) Dosage adjustment of amitriptyline/nortriptyline, propofol, warfarin, and zidovudine may be necessary if used concomitantly with Valproic acid ( 7.2 ) Topiramate: Hyperammonemia and encephalopathy
Source: FDA drug label (VALPROIC ACID), PAI Holdings, LLC dba PAI Pharma, effective January 24, 2025 (SPL set 7d5cb52e-37dd-4dfa-a6f4-09f9548846c6), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Rufinamide | Valproic acid | |
|---|---|---|
| Labeled for | n/a | Seizures and epilepsy, Migraine |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.203 per mL 40 mg/mL suspension | $0.243 per capsule 250 mg capsule |
| Shortage now | No current entry | Listed; available |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once