What the FDA labels say about taking them together
Doxazosin and macitentan/tadalafil
Macitentan/tadalafil's FDA label of April 11, 2025 names doxazosin in its drug interactions section; doxazosin's label does not name macitentan/tadalafil itself but warns about its class (PDE5 inhibitors). The macitentan/tadalafil label: “Therefore, the combination of OPSYNVI and doxazosin is not recommended. Antihypertensives PDE5 inhibitors, including tadalafil, are mild systemic vasodilators.”
Check it at the source: the doxazosin FDA label on DailyMed (effective October 15, 2023, Viatris Specialty LLC); the macitentan/tadalafil FDA label on DailyMed (effective April 11, 2025, Actelion Pharmaceuticals US, Inc.).
What does the doxazosin label say about macitentan/tadalafil?
Doxazosin's label does not name macitentan/tadalafil itself; it warns about its class (PDE5 inhibitors):
Doxazosin label, warnings and precautionsConcomitant administration of CARDURA with a PDE-5 inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension.
Source: FDA drug label (Cardura), Viatris Specialty LLC, effective October 15, 2023 (SPL set 5e1f5e49-2da1-43ab-9795-228a8bcc5a82), via openFDA; the full label on DailyMed
What does the macitentan/tadalafil label say about doxazosin?
Macitentan/tadalafil label, drug interactionsTherefore, the combination of OPSYNVI and doxazosin is not recommended [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.2) ]. Antihypertensives PDE5 inhibitors, including tadalafil, are mild systemic vasodilators.
Source: FDA drug label (OPSYNVI), Actelion Pharmaceuticals US, Inc., effective April 11, 2025 (SPL set 6945b183-18d3-40de-afd1-c88e33cc1a63), 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
| Doxazosin | Macitentan/tadalafil | |
|---|---|---|
| Labeled for | Enlarged prostate (BPH), High blood pressure | Pulmonary arterial hypertension |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0752 per tablet 1 mg tablet | 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