What the FDA labels say about taking them together
Diazepam and valproic acid
Valproic acid's FDA label of January 24, 2025 names diazepam in its drug interactions section; diazepam's label does not name valproic acid itself but warns about its class (Anti-seizure medicines). The valproic acid label: “Monitoring of valproate concentrations is recommended Co-administration of valproate can affect the pharmacokinetics of other drugs by inhibiting their metabolism or protein binding displacement Patients stabilized on …”
Check it at the source: the diazepam FDA label on DailyMed (effective August 11, 2026, Waylis Therapuetics LLC); the valproic acid FDA label on DailyMed (effective January 24, 2025, PAI Holdings, LLC dba PAI Pharma).
What does the diazepam label say about valproic acid?
Diazepam's label does not name valproic acid itself; it warns about its class (Anti-seizure medicines):
Diazepam label, warnings and precautionsBehavior and Ideation Antiepileptic drugs (AEDs), including VALTOCO, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication.
Diazepam label, warnings and precautionsPatients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior.
Source: FDA drug label (Valium), Waylis Therapuetics LLC, effective August 11, 2026 (SPL set 260e2041-2bb3-482f-850e-b5d47a7bdbe6), via openFDA; the full label on DailyMed
What does the valproic acid label say about diazepam?
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
| Diazepam | Valproic acid | |
|---|---|---|
| Labeled for | Anxiety, Muscle spasms and spasticity | Seizures and epilepsy, Migraine |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0283 per tablet 10 mg tablet | $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