What the FDA labels say about taking them together
Dienogest/estradiol and diltiazem
Dienogest/estradiol's FDA label of June 26, 2024 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name dienogest/estradiol. The dienogest/estradiol label: “Concomitant administration of moderate or strong CYP3A4 inhibitors like azole antifungals, verapamil, macrolides, diltiazem, and grapefruit increase the serum concentrations of both estradiol and dienogest.”
Check it at the source: the dienogest/estradiol FDA label on DailyMed (effective June 26, 2024, Bayer HealthCare Pharmaceuticals Inc.); the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC).
What does the dienogest/estradiol label say about diltiazem?
Dienogest/estradiol label, drug interactionsConcomitant administration of moderate or strong CYP3A4 inhibitors like azole antifungals (for example, ketoconazole, itraconazole, voriconazole, fluconazole), verapamil, macrolides (for example, clarithromycin, erythromycin), diltiazem, and grapefruit increase the serum concentrations of both estradiol and dienogest.
Source: FDA drug label (Natazia), Bayer HealthCare Pharmaceuticals Inc., effective June 26, 2024 (SPL set 02c91fba-9c47-43ef-ac78-e82369798834), via openFDA; the full label on DailyMed
What does the diltiazem label say about dienogest/estradiol?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name dienogest/estradiol in these sections. A label lists what its studies and reports found; it is not a complete list.
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
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
| Dienogest/estradiol | Diltiazem | |
|---|---|---|
| Labeled for | Birth control | High blood pressure, Angina, Atrial fibrillation |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $8.46 per tablet 28 tablet | $0.144 per capsule 24h ER(cd) 120 mg capsule |
| Shortage now | No current entry | A presentation being discontinued |
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