What the FDA labels say about taking them together
Valproic acid and zidovudine
Valproic acid's FDA label of January 24, 2025 names zidovudine in its drug interactions section, and zidovudine's label names valproic acid too. The valproic acid label: “… Dosage adjustment of amitriptyline/nortriptyline, propofol, warfarin, and zidovudine may be necessary if used concomitantly with Valproic acid Topiramate: Hyperammonemia and encephalopathy”
Check it at the source: the valproic acid FDA label on DailyMed (effective January 24, 2025, PAI Holdings, LLC dba PAI Pharma); the zidovudine FDA label on DailyMed (effective February 10, 2025, Aurobindo Pharma Limited).
What does the valproic acid label say about zidovudine?
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
What does the zidovudine label say about valproic acid?
Retrovir label (ViiV Healthcare Company, October 30, 2013), drug interactionsFor patients experiencing pronounced anemia or other severe zidovudine-associated events while receiving chronic administration of zidovudine and some of the drugs (e.g., fluconazole, valproic acid) listed in Table 4, zidovudine dose reduction may be considered.
Source: FDA drug label (Retrovir, NDA019951), ViiV Healthcare Company, effective October 30, 2013 (SPL set 360d8a6d-d3b6-43ef-8764-e99d831880a4), via openFDA
Source: FDA drug label (Zidovudine), Aurobindo Pharma Limited, effective February 10, 2025 (SPL set 51abd2ce-6be1-412d-b806-5f24935ac5e3), 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
| Valproic acid | Zidovudine | |
|---|---|---|
| Labeled for | Seizures and epilepsy, Migraine | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.243 per capsule 250 mg capsule | $0.464 per tablet 300 mg tablet |
| Shortage now | Listed; available | No current entry |
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