What the FDA labels say about taking them together
Glucagon and phentolamine
Glucagon's FDA label of August 11, 2026 names phentolamine in its warnings and precautions section; the phentolamine labels PlainMeds reads (2) do not name glucagon. The glucagon label: “If the patient develops a substantial increase in blood pressure and a previously undiagnosed pheochromocytoma is suspected, 5 to 10 mg of phentolamine mesylate, administered intravenously, has been shown to be …”
Check it at the source: the glucagon FDA label on DailyMed (effective August 11, 2026, Amphastar Pharmaceuticals, Inc.); the phentolamine FDA label on DailyMed (effective March 15, 2026, Oyster Point Pharma, Inc.).
What does the glucagon label say about phentolamine?
Glucagon label, warnings and precautionsIf the patient develops a substantial increase in blood pressure and a previously undiagnosed pheochromocytoma is suspected, 5 to 10 mg of phentolamine mesylate, administered intravenously, has been shown to be effective in lowering blood pressure.
Source: FDA drug label (Glucagon), Amphastar Pharmaceuticals, Inc., effective August 11, 2026 (SPL set 8cc40354-b5ac-45b6-a211-93b44444f2a3), via openFDA; the full label on DailyMed
What does the phentolamine label say about glucagon?
Phentolamine's label (effective March 15, 2026) and its 1 other brand-application label do not name glucagon in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Ryzumvi), NDA217064 (Famygen Life Sci), as published by Oyster Point Pharma, Inc., effective March 15, 2026 (SPL set 96bb1e53-c2cc-4e60-a21a-db0269c371bf), 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
| Glucagon | Phentolamine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $154.20 per kit 1 mg emergency kit | n/a |
| 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