What the FDA labels say about taking them together
Ephedrine and quinidine
Ephedrine's FDA label of September 16, 2024 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name ephedrine. The ephedrine label: “… Examples: α-adrenergic antagonists, β-adrenergic receptor antagonists, reserpine, quinidine, mephentermine Other Drug Interactions G u anethidine C linical Impact:”
Check it at the source: the ephedrine FDA label on DailyMed (effective September 16, 2024, Nexus Pharmaceuticals, LLC); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the ephedrine label say about quinidine?
Ephedrine label, drug interactionsClinical Impact: These drugs augment the pressor effect of ephedrine. Intervention: Carefully monitor the blood pressure of individuals who have received both EMERPHED and EMERPHED-PFS and any of these drugs. Drugs that Antagonize the Pressor Effect α-adrenergic antagonists, β-adrenergic receptor antagonists, reserpine, quinidine, mephentermine
Akovaz label (Exela Pharma Sciences, LLC, November 27, 2020), drug interactionsClinical Impact: These drugs antagonize the pressor effect of ephedrine. Intervention: Carefully monitor the blood pressure of individuals who have received both ephedrine and any of these drugs. Examples: α-adrenergic antagonists, β-adrenergic receptor antagonists, reserpine, quinidine, mephentermine Other Drug Interactions Guanethidine
Source: FDA drug label (Akovaz, NDA208289), Exela Pharma Sciences, LLC, effective November 27, 2020 (SPL set e92f3eda-33eb-4b34-9e8b-db8d32a5dbd9), via openFDA
Source: FDA drug label (Ephedrine Sulfate, NDA208943), Par Health USA, LLC, effective March 17, 2026 (SPL set 38723cb3-dfca-4c81-8c6f-63dd99929191), via openFDA
Source: FDA drug label (Emerphed PFS), Nexus Pharmaceuticals, LLC, effective September 16, 2024 (SPL set 14601778-93ac-43ec-b66b-5a942317133f), via openFDA; the full label on DailyMed
What does the quinidine label say about ephedrine?
Quinidine's label (effective February 1, 2018) does not name ephedrine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Quinidine Gluconate), Sun Pharmaceutical Industries, Inc., effective February 1, 2018 (SPL set 5023f053-fcc4-4c2c-aa59-9ec198ad185e), 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
| Ephedrine | Quinidine | |
|---|---|---|
| Labeled for | Asthma | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $4.92 per tablet 324 mg tablet |
| 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