What the FDA labels say about taking them together
Dihydroergotamine and nitroglycerin
Nitroglycerin's FDA label of February 15, 2023 names dihydroergotamine in its drug interactions section; the dihydroergotamine labels PlainMeds reads (4) do not name nitroglycerin. The nitroglycerin label: “Oral administration of nitroglycerin markedly decreases the first-pass metabolism of dihydroergotamine and subsequently increases its oral bioavailability.”
Check it at the source: the dihydroergotamine FDA label on DailyMed (effective March 6, 2025, Oceanside Pharmaceuticals); the nitroglycerin FDA label on DailyMed (effective February 15, 2023, Viatris Specialty LLC).
What does the dihydroergotamine label say about nitroglycerin?
Dihydroergotamine's label (effective March 6, 2025) and its 3 other brand-application labels do not name nitroglycerin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Dihydroergotamine Mesylate), NDA020148 (Bausch), as published by Oceanside Pharmaceuticals, effective March 6, 2025 (SPL set 977de209-c53a-4cb4-9f3f-1e850600a9dc), via openFDA; the full label on DailyMed
What does the nitroglycerin label say about dihydroergotamine?
Nitroglycerin label, drug interactionsOral administration of nitroglycerin markedly decreases the first-pass metabolism of dihydroergotamine and subsequently increases its oral bioavailability.
Source: FDA drug label (Rectiv, NDA021359), Allergan, Inc., effective September 8, 2026 (SPL set 603aa9ed-54c4-4a35-ade4-690fa44850e4), via openFDA
Source: FDA drug label (Nitrostat), Viatris Specialty LLC, effective February 15, 2023 (SPL set 9a52da75-d0af-4237-96c0-0b12adfa8636), 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
| Dihydroergotamine | Nitroglycerin | |
|---|---|---|
| Labeled for | Migraine | Angina, High blood pressure, Heart failure, Heart attack and coronary artery disease |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $29.44 per mL 4 mg/mL nasal spray | $0.127 per tablet 0.4 mg tablet sl |
| 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