What the FDA labels say about taking them together
Propranolol and zileuton
Propranolol's FDA label of January 15, 2026 names zileuton in its drug interactions section, and zileuton's label names propranolol too. The propranolol label: “… cimetidine, ciprofloxacin, fluvoxamine, isoniazid, ritonavir, theophylline, zileuton, zolmitriptan, and rizatriptan.”
Check it at the source: the propranolol FDA label on DailyMed (effective January 15, 2026, Mylan Pharmaceuticals Inc.); the zileuton FDA label on DailyMed (effective July 29, 2022, Strides Pharma Science Limited).
What does the propranolol label say about zileuton?
Propranolol label, drug interactionsSubstrates or Inhibitors of CYP1A2 Blood levels and/or toxicity of propranolol may be increased by co-administration with substrates or inhibitors of CYP1A2, such as imipramine, cimetidine, ciprofloxacin, fluvoxamine, isoniazid, ritonavir, theophylline, zileuton, zolmitriptan, and rizatriptan.
Source: FDA drug label (Propranolol Hydrochloride), Mylan Pharmaceuticals Inc., effective January 15, 2026 (SPL set b94dcec7-7633-4a33-9cea-48161adeaf93), via openFDA; the full label on DailyMed
What does the zileuton label say about propranolol?
Zileuton label, drug interactionsCoadministration of zileuton immediate-release tablets and propranolol results in a significant increase in propranolol concentrations.
Source: FDA drug label (Zileuton), Strides Pharma Science Limited, effective July 29, 2022 (SPL set a826d16f-df07-447b-b050-b9a02ea1f89e), 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
| Propranolol | Zileuton | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation, Migraine | Asthma |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0493 per tablet 20 mg tablet | $2.05 per tablet 600 mg tablet |
| Shortage now | In shortage | 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