What the FDA labels say about taking them together
Nortriptyline and valproic acid
Valproic acid's FDA label of January 24, 2025 names nortriptyline in its drug interactions section; the nortriptyline label PlainMeds reads does not name valproic acid. The valproic acid label: “… and titrate to clinically effective dose Dosage adjustment of amitriptyline/nortriptyline, propofol, warfarin, and zidovudine may be necessary if used concomitantly with Valproic acid Topiramate: Hyperammonemia and …”
Check it at the source: the nortriptyline FDA label on DailyMed (effective December 4, 2024); the valproic acid FDA label on DailyMed (effective January 24, 2025, PAI Holdings, LLC dba PAI Pharma).
What does the nortriptyline label say about valproic acid?
Nortriptyline's label (effective December 4, 2024) does not name valproic acid in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (PAMELOR), SpecGx LLC, effective December 4, 2024 (SPL set e17dc299-f52d-414d-ab6e-e809bd6f8acb), via openFDA; the full label on DailyMed
What does the valproic acid label say about nortriptyline?
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
| Nortriptyline | Valproic acid | |
|---|---|---|
| Labeled for | Depression | Seizures and epilepsy, Migraine |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.113 per capsule 10 mg capsule | $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