What the FDA labels say about taking them together
Diltiazem and midazolam
Diltiazem's FDA label of August 7, 2026 names midazolam in its drug interactions section, and midazolam's label names diltiazem too. The midazolam label: “Concomitant use of CYP3A4 inhibitors may result in prolonged sedation because of a decrease in plasma clearance of midazolam.”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the midazolam FDA label on DailyMed (effective January 1, 2024, Fresenius Kabi USA, LLC).
What does the diltiazem label say about midazolam?
Diltiazem label, drug interactionsBenzodiazepines: Studies showed that diltiazem increased the AUC of midazolam and triazolam by 3- to 4-fold and the C max by 2-fold, compared to placebo.
Source: FDA drug label (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
What does the midazolam label say about diltiazem?
Midazolam label, drug interactionsOther Drug Interactions Caution is advised when midazolam is administered concomitantly with drugs that are known to inhibit the P450-3A4 enzyme system such as cimetidine (not ranitidine), erythromycin, diltiazem, verapamil, ketoconazole and itraconazole.
N/A label (Rafa Laboratories, Ltd., February 18, 2026), drug interactionsCytochrome P450-3A4 Inhibitors Caution is advised when Midazolam Injection is administered concomitantly with drugs that are known to inhibit the P450-3A4 enzyme system (e.g., cimetidine, erythromycin, diltiazem, verapamil, ketoconazole, and itraconazole).
Nayzilam label (UCB, Inc., January 19, 2023), drug interactions7.1 CYP3A4 Inhibitors Clinical Impact: Concomitant use of CYP3A4 inhibitors may result in prolonged sedation because of a decrease in plasma clearance of midazolam. Intervention: Avoid co-administration of NAYZILAM with moderate or strong CYP3A4 inhibitors. NAYZILAM should be used with caution when co-administered with mild CYP3A4 inhibitors. Examples: Moderate CYP3A4 inhibitors: erythromycin, diltiazem, verapamil Strong CYP3A4 inhibitors: ketoconazole, itraconazole …
Midazolam In Sodium Chloride label (WG Critical Care, LLC., July 31, 2025), drug interactionsConcomitant administration with drugs that are known to inhibit the P450-3A4 enzyme system, such as cimetidine (not ranitidine), erythromycin, diltiazem, verapamil, ketoconazole and itraconazole, may result in prolonged sedation due to a decrease in plasma clearance of midazolam.
Source: FDA drug label (N/A, NDA216359), Rafa Laboratories, Ltd., effective February 18, 2026 (SPL set d7362b4d-68a3-99a0-e053-2995a90a4f60), via openFDA
Source: FDA drug label (Nayzilam, NDA211321), UCB, Inc., effective January 19, 2023 (SPL set 2b29422e-54d5-4a49-8522-e9cf752368c3), via openFDA
Source: FDA drug label (Midazolam In Sodium Chloride, NDA211844), WG Critical Care, LLC., effective July 31, 2025 (SPL set f051776f-94c5-4e34-80ed-f45b9c36881e), via openFDA
Source: FDA drug label (Midazolam), Fresenius Kabi USA, LLC, effective January 1, 2024 (SPL set 1cc9ba6e-fa1b-405e-9de8-720c567b2a73), 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
| Diltiazem | Midazolam | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | $0.233 per mL 2 mg/2 mL vial |
| Shortage now | A presentation being discontinued | In shortage |
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