What the FDA labels say about taking them together
Dofetilide and verapamil
Dofetilide's FDA label of April 21, 2026 names verapamil in its contraindications section; the verapamil labels PlainMeds reads (4) do not name dofetilide. The dofetilide label: “The concomitant use of verapamil or the cation transport system inhibitors cimetidine, trimethoprim, or ketoconazole with TIKOSYN is contraindicated, as each of these drugs cause a substantial increase in dofetilide …”
Check it at the source: the dofetilide FDA label on DailyMed (effective April 21, 2026, Pfizer Laboratories Div Pfizer Inc); the verapamil FDA label on DailyMed (effective April 6, 2026, Zydus Pharmaceuticals (USA) Inc.).
What does the dofetilide label say about verapamil?
Dofetilide label, contraindicationsThe concomitant use of verapamil or the cation transport system inhibitors cimetidine, trimethoprim (alone or in combination with sulfamethoxazole), or ketoconazole with TIKOSYN is contraindicated (see WARNINGS and PRECAUTIONS, Drug-Drug Interactions ), as each of these drugs cause a substantial increase in dofetilide plasma concentrations.
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 verapamil label say about dofetilide?
Verapamil's label (effective April 6, 2026) and its 3 other brand-application labels do not name dofetilide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Verapamil hydrochloride), Zydus Pharmaceuticals (USA) Inc., effective April 6, 2026 (SPL set e19ab8d8-dae5-489d-9805-7e7407bea06d), 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 | Verapamil | |
|---|---|---|
| Labeled for | Atrial fibrillation | High blood pressure, Atrial fibrillation, Angina |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.203 per capsule 125 mcg capsule | $0.191 per tablet 180 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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