What the FDA labels say about taking them together
Diazepam and modafinil
Modafinil's FDA label of October 16, 2025 names diazepam in its drug interactions section; the diazepam labels PlainMeds reads (4) do not name modafinil. The modafinil label: “Effects of PROVIGIL on CYP2C19 Substrates Elimination of drugs that are substrates for CYP2C19 may be prolonged by PROVIGIL via inhibition of metabolic enzymes, with resultant higher systemic exposure.”
Check it at the source: the diazepam FDA label on DailyMed (effective August 11, 2026, Waylis Therapuetics LLC); the modafinil FDA label on DailyMed (effective October 16, 2025, Golden State Medical Supply, Inc.).
What does the diazepam label say about modafinil?
Diazepam's label (effective August 11, 2026) and its 3 other brand-application labels do not name modafinil in these sections. A label lists what its studies and reports found; it is not a complete list.
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 modafinil label say about diazepam?
Modafinil label, drug interactionsEffects of PROVIGIL on CYP2C19 Substrates Elimination of drugs that are substrates for CYP2C19 (e.g., phenytoin, diazepam, propranolol, omeprazole, and clomipramine) may be prolonged by PROVIGIL via inhibition of metabolic enzymes, with resultant higher systemic exposure.
Source: FDA drug label (Provigil), NDA020717 (Nuvo Pharms), as published by Golden State Medical Supply, Inc., effective October 16, 2025 (SPL set 3b8d1c32-dac9-50e6-e063-6394a90aa5a5), 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 | Modafinil | |
|---|---|---|
| Labeled for | Anxiety, Muscle spasms and spasticity | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0283 per tablet 10 mg tablet | $0.344 per tablet 200 mg tablet |
| 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