What the FDA labels say about taking them together
Ivosidenib and ritonavir
Ritonavir's FDA label of July 23, 2026 names ivosidenib in its drug interactions section; the ivosidenib label PlainMeds reads does not name ritonavir. The ritonavir label: “… the class of protease inhibitors. Avoid co-administration of encorafenib or ivosidenib with NORVIR due to potential risk of serious adverse events such as QT interval prolongation. …”
Check it at the source: the ivosidenib FDA label on DailyMed (effective December 22, 2025, Servier Pharmaceutical LLC); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the ivosidenib label say about ritonavir?
Ivosidenib's label (effective December 22, 2025) does not name ritonavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TIBSOVO), Servier Pharmaceutical LLC, effective December 22, 2025 (SPL set 65d254c0-67ad-42c4-b972-ad463b755b2d), via openFDA; the full label on DailyMed
What does the ritonavir label say about ivosidenib?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Anticancer Agents: abemaciclib, apalutamide, dasatinib, encorafenib, ibrutinib, ivosidenib, neratinib, nilotinib, venetoclax, vinblastine, vincristine; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ anticancer agents ↓ ritonavir #; Clinical Comment: Apalutamide is contraindicated due to potential for loss of virologic response and possible resistance to NORVIR or to the class of protease inhibitors [see Contraindications () ]. Avoid co-administration of encorafenib or ivosidenib with NORVIR due to potential risk of serious adverse events such as QT interval prolongation. …
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
| Ivosidenib | Ritonavir | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | 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