What the FDA labels say about taking them together
Macitentan and ritonavir
Macitentan's FDA label of April 11, 2025 names ritonavir in its drug interactions section; the ritonavir label PlainMeds reads does not name macitentan. The macitentan label: “Strong CYP3A4 inhibitors (ketoconazole, ritonavir) increase exposure to macitentan: avoid co-administration with OPSUMIT.”
Check it at the source: the macitentan FDA label on DailyMed (effective April 11, 2025, Actelion Pharmaceuticals US, Inc.); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the macitentan label say about ritonavir?
Macitentan label, drug interactionsStrong CYP3A4 inhibitors (ketoconazole, ritonavir) increase exposure to macitentan: avoid co-administration with OPSUMIT ( 7.2 , 12.3 ).
Source: FDA drug label (OPSUMIT), Actelion Pharmaceuticals US, Inc., effective April 11, 2025 (SPL set 1e484a50-55db-4b85-8c57-6cd1b0353abd), via openFDA; the full label on DailyMed
What does the ritonavir label say about macitentan?
Ritonavir's label (effective July 23, 2026) does not name macitentan in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), 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
| Macitentan | Ritonavir | |
|---|---|---|
| Labeled for | Pulmonary arterial hypertension | HIV |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.607 per tablet 100 mg tablet |
| 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