What the FDA labels say about taking them together
Arsenic trioxide and furosemide
Arsenic trioxide's FDA label of July 23, 2021 names furosemide in its warnings and precautions section; the furosemide labels PlainMeds reads (4) do not name arsenic trioxide. The arsenic trioxide label: “Consider testing thiamine levels in patients at risk for thiamine deficiency.”
Check it at the source: the arsenic trioxide FDA label on DailyMed (effective July 23, 2021, Amneal Pharmaceuticals LLC); the furosemide FDA label on DailyMed (effective September 30, 2025, Validus Pharmaceuticals LLC).
What does the arsenic trioxide label say about furosemide?
Arsenic trioxide label, warnings and precautionsConsider testing thiamine levels in patients at risk for thiamine deficiency (e.g., chronic alcohol use, malabsorption, nutritional deficiency, concomitant use of furosemide).
Source: FDA drug label (Arsenic Trioxide), Amneal Pharmaceuticals LLC, effective July 23, 2021 (SPL set 5845022e-8c01-451b-ae49-a28e58c5f845), via openFDA; the full label on DailyMed
What does the furosemide label say about arsenic trioxide?
Furosemide's label (effective September 30, 2025) and its 3 other brand-application labels do not name arsenic trioxide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Lasix), Validus Pharmaceuticals LLC, effective September 30, 2025 (SPL set 2c9b4d8f-0770-482d-a9e6-9c616a440b1a), 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
| Arsenic trioxide | Furosemide | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Heart failure, High blood pressure, Edema (fluid retention) |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $0.490 per mL 20 mg/2 mL vial |
| Shortage now | A presentation being discontinued | In shortage |
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