What the FDA labels say about taking them together
Ceritinib and nirmatrelvir/ritonavir
Nirmatrelvir/ritonavir's FDA label of February 19, 2026 names ceritinib in its drug interactions section; the ceritinib label PlainMeds reads does not name nirmatrelvir/ritonavir. The nirmatrelvir/ritonavir label: “Avoid co-administration of encorafenib or ivosidenib due to potential risk of serious adverse events such as QT interval prolongation. Avoid use of neratinib, venetoclax or ibrutinib. …”
Check it at the source: the ceritinib FDA label on DailyMed (effective December 15, 2025, Novartis Pharmaceuticals Corporation); the nirmatrelvir/ritonavir FDA label on DailyMed (effective February 19, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the ceritinib label say about nirmatrelvir/ritonavir?
Ceritinib's label (effective December 15, 2025) does not name nirmatrelvir/ritonavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ZYKADIA), Novartis Pharmaceuticals Corporation, effective December 15, 2025 (SPL set fff5d805-4ffd-4e8e-8e63-6f129697563e), via openFDA; the full label on DailyMed
What does the nirmatrelvir/ritonavir label say about ceritinib?
Nirmatrelvir/ritonavir label, drug interactionsDrug Class: Anticancer drugs; Drugs within Class: abemaciclib, ceritinib, dasatinib, encorafenib, ibrutinib, ivosidenib, neratinib, nilotinib, venetoclax, vinblastine, vincristine; Effect on Concentration: ↑ anticancer drugs; Clinical Comments: Avoid co-administration of encorafenib or ivosidenib due to potential risk of serious adverse events such as QT interval prolongation. Avoid use of neratinib, venetoclax or ibrutinib. Co-administration of vincristine and vinblastine may lead to significant hematologic or gastrointestinal side effects. For further information, refer to the individual product prescribing information for anticancer drug.
Source: FDA drug label (Paxlovid), Pfizer Laboratories Div Pfizer Inc, effective February 19, 2026 (SPL set 8a99d6d6-fd9e-45bb-b1bf-48c7f761232a), 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
| Ceritinib | Nirmatrelvir/ritonavir | |
|---|---|---|
| Labeled for | Lung cancer | COVID-19 |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $49.24 per unit 300-100 mg dose pack |
| 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