What the FDA labels say about taking them together
Dofetilide and vandetanib
Vandetanib's FDA label of April 23, 2026 names dofetilide in its warnings and precautions section; the dofetilide label PlainMeds reads does not name vandetanib. The vandetanib label: “Avoid administration of CAPRELSA with anti-arrhythmic drugs and other drugs that may prolong the QT interval.”
Check it at the source: the dofetilide FDA label on DailyMed (effective April 21, 2026, Pfizer Laboratories Div Pfizer Inc); the vandetanib FDA label on DailyMed (effective April 23, 2026, Genzyme Corporation).
What does the dofetilide label say about vandetanib?
Dofetilide's label (effective April 21, 2026) does not name vandetanib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Tikosyn), Pfizer Laboratories Div Pfizer Inc, effective April 21, 2026 (SPL set 02438044-d6a3-49e9-a1ac-3aad21ef2c8c), via openFDA; the full label on DailyMed
What does the vandetanib label say about dofetilide?
Vandetanib label, warnings and precautionsAvoid administration of CAPRELSA with anti-arrhythmic drugs (including but not limited to amiodarone, disopyramide, procainamide, sotalol, dofetilide) and other drugs that may prolong the QT interval (including but not limited to chloroquine, clarithromycin, dolasetron, granisetron, haloperidol, methadone, moxifloxacin, and pimozide) [see Drug Interactions (7.4) and Clinical Pharmacology (12.2) ].
Source: FDA drug label (CAPRELSA), Genzyme Corporation, effective April 23, 2026 (SPL set e5721cb8-4185-47b9-bbb3-1c587e558a03), 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
| Dofetilide | Vandetanib | |
|---|---|---|
| Labeled for | Atrial fibrillation | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.203 per capsule 125 mcg capsule | 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