What the FDA labels say about taking them together
Diphenhydramine and zaleplon
Zaleplon's FDA label of May 8, 2024 names diphenhydramine in its drug interactions section; the diphenhydramine label PlainMeds reads does not name zaleplon.
Check it at the source: the diphenhydramine FDA label on DailyMed (effective November 18, 2025, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.); the zaleplon FDA label on DailyMed (effective May 8, 2024, Aurobindo Pharma Limited).
What does the diphenhydramine label say about zaleplon?
Diphenhydramine's label (effective November 18, 2025) does not name zaleplon in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Diphenhydramine Hydrochloride), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective November 18, 2025 (SPL set 6178d3a1-0741-49a4-be81-c4f7d29f8b2a), via openFDA; the full label on DailyMed
What does the zaleplon label say about diphenhydramine?
Zaleplon label, drug interactionsDiphenhydramine: Diphenhydramine is reported to be a weak inhibitor of aldehyde oxidase in rat liver, but its inhibitory effects in human liver are not known.
Source: FDA drug label (ZALEPLON), Aurobindo Pharma Limited, effective May 8, 2024 (SPL set e092f3ca-bf44-4568-a72c-3fb2cf5b192b), 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
| Diphenhydramine | Zaleplon | |
|---|---|---|
| Labeled for | Cough and cold, Allergies, Pain | Insomnia |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.898 per mL 50 mg/mL vial | $0.141 per capsule 10 mg capsule |
| 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