What the FDA labels say about taking them together
Cabozantinib and phenytoin
Cabozantinib's FDA label (Cometriq) of October 18, 2025 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name cabozantinib. The cabozantinib label: “Avoid chronic co-administration of strong CYP3A4 inducers with COMETRIQ or increase the dosage of COMETRIQ if concomitant use with strong CYP3A4 inducers cannot be avoided.”
Check it at the source: the cabozantinib FDA label on DailyMed (effective October 19, 2025, Exelixis, Inc.); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the cabozantinib label say about phenytoin?
Cometriq label (Exelixis, Inc., October 18, 2025), drug interactionsAvoid chronic co-administration of strong CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital, St. John’s Wort) with COMETRIQ or increase the dosage of COMETRIQ if concomitant use with strong CYP3A4 inducers cannot be avoided [see Dosage and Administration ( 2.2 ), Clinical Pharmacology ( 12.3 )].
Source: FDA drug label (Cometriq, NDA203756), Exelixis, Inc., effective October 18, 2025 (SPL set 1a0c3bea-c87b-4d25-bb44-5f0174da6b34), via openFDA
Source: FDA drug label (CABOMETYX), Exelixis, Inc., effective October 19, 2025 (SPL set 3850cce2-6137-42e5-a792-d318c4a4b3b5), via openFDA; the full label on DailyMed
What does the phenytoin label say about cabozantinib?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name cabozantinib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenytek), Mylan Pharmaceuticals Inc., effective October 15, 2024 (SPL set 0f94c791-8b07-4b41-927e-c9f28bec5f60), 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
| Cabozantinib | Phenytoin | |
|---|---|---|
| Labeled for | n/a | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.145 per capsule 100 mg capsule |
| 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