What the FDA labels say about taking them together
Ondansetron and quizartinib
Quizartinib's FDA label of April 16, 2026 names ondansetron in its drug interactions section; the ondansetron label PlainMeds reads does not name quizartinib. The quizartinib label: “… of QT prolonging drugs include but are not limited to antifungal azoles, ondansetron, granisetron, azithromycin, pentamidine, doxycycline, moxifloxacin, atovaquone, prochlorperazine, and tacrolimus.”
Check it at the source: the ondansetron FDA label on DailyMed (effective January 8, 2026, Glenmark Pharmaceuticals Inc., USA); the quizartinib FDA label on DailyMed (effective April 16, 2026, Daiichi Sankyo Inc.).
What does the ondansetron label say about quizartinib?
Ondansetron's label (effective January 8, 2026) does not name quizartinib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Ondansetron), Glenmark Pharmaceuticals Inc., USA, effective January 8, 2026 (SPL set eee5217a-eba8-463a-812d-bf3c66f0934f), via openFDA; the full label on DailyMed
What does the quizartinib label say about ondansetron?
Quizartinib label, drug interactionsQT Interval Prolonging Drugs Clinical Impact VANFLYTA prolongs the QT/QTc interval. Coadministration of VANFLYTA with other drugs that prolong the QT interval may further increase the incidence of QT prolongation [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.2) ]. Prevention or Management Monitor patients more frequently with ECG if co-administration of VANFLYTA with drugs known to prolong the QT interval is required. Examples of QT prolonging drugs include but are not limited to antifungal azoles, ondansetron, granisetron, azithromycin, pentamidine, doxycycline, moxifloxacin, atovaquone, prochlorperazine, and tacrolimus.
Source: FDA drug label (VANFLYTA), Daiichi Sankyo Inc., effective April 16, 2026 (SPL set 29cdbcfe-497d-4e78-bb7b-2d4acafe8e86), 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
| Ondansetron | Quizartinib | |
|---|---|---|
| Labeled for | Nausea and vomiting | Leukemia, lymphoma and myeloma |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0582 per tablet 4 mg tablet | n/a |
| 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