What the FDA labels say about taking them together
Diazepam and ketoconazole
Diazepam's FDA label of August 11, 2026 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name diazepam. The diazepam label: “Inhibitors of CYP2C19 and CYP3A4 Inhibitors of CYP2C19 and CYP3A4 could decrease the rate of diazepam elimination; therefore, adverse reactions to VALTOCO may be increased.”
Check it at the source: the diazepam FDA label on DailyMed (effective August 11, 2026, Waylis Therapuetics LLC); the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC).
What does the diazepam label say about ketoconazole?
Diazepam label, drug interactionsAt present, this reaction is known to occur with cimetidine, ketoconazole, fluvoxamine, fluoxetine, and omeprazole.
Valtoco label (Neurelis, Inc, June 3, 2026), drug interactionsInhibitors of CYP2C19 and CYP3A4 Inhibitors of CYP2C19 (e.g., cimetidine, quinidine, and tranylcypromine) and CYP3A4 (e.g., ketoconazole, troleandomycin, and clotrimazole) could decrease the rate of diazepam elimination; therefore, adverse reactions to VALTOCO may be increased.
Source: FDA drug label (Valtoco, NDA211635), Neurelis, Inc, effective June 3, 2026 (SPL set 1a8bcc90-68fa-474d-832c-0df01e825f39), via openFDA
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 ketoconazole label say about diazepam?
Ketoconazole's label (effective January 28, 2026) does not name diazepam in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ketoconazole), E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC, effective January 28, 2026 (SPL set cad7c647-34a9-4e4e-83b3-8d78e58f588f), 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 | Ketoconazole | |
|---|---|---|
| Labeled for | Anxiety, Muscle spasms and spasticity | Fungal infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0283 per tablet 10 mg tablet | $0.249 per gram 2% cream |
| Shortage now | No current entry | 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