What the FDA labels say about taking them together
Ritonavir and vinblastine
Ritonavir's FDA label of July 23, 2026 names vinblastine in its drug interactions section; the vinblastine label PlainMeds reads does not name ritonavir. The ritonavir label: “… use of neratinib, venetoclax or ibrutinib with NORVIR. For vincristine and vinblastine, consideration should be given to temporarily withholding the ritonavir containing antiretroviral regimen in patients who develop …”
Check it at the source: the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.); the vinblastine FDA label on DailyMed (effective April 15, 2025, Fresenius Kabi USA, LLC).
What does the ritonavir label say about vinblastine?
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
What does the vinblastine label say about ritonavir?
Vinblastine's label (effective April 15, 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 (Vinblastine Sulfate), Fresenius Kabi USA, LLC, effective April 15, 2025 (SPL set f073b58e-56d6-4c8d-a2ce-b37719402d77), 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
| Ritonavir | Vinblastine | |
|---|---|---|
| Labeled for | HIV | Leukemia, lymphoma and myeloma |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.607 per tablet 100 mg tablet | n/a |
| Shortage now | A presentation being discontinued | 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