What the FDA labels say about taking them together
Cyclophosphamide and paclitaxel
Cyclophosphamide's FDA label (Frindovyx) of August 26, 2026 names paclitaxel in its drug interactions section; the paclitaxel labels PlainMeds reads (4) do not name cyclophosphamide. The cyclophosphamide label: “Natalizumab Paclitaxel: Increased hematotoxicity has been reported when cyclophosphamide was administered after paclitaxel infusion.”
Check it at the source: the cyclophosphamide FDA label on DailyMed (effective January 19, 2026, Amneal Pharmaceuticals LLC); the paclitaxel FDA label on DailyMed (effective January 21, 2026, Natco Pharma USA LLC).
What does the cyclophosphamide label say about paclitaxel?
Frindovyx label (AVYXA Pharma, LLC, August 26, 2026), drug interactionsACE inhibitors can cause leukopenia. ● Natalizumab ● Paclitaxel: Increased hematotoxicity has been reported when cyclophosphamide was administered after paclitaxel infusion. ● Thiazide diuretics ● Zidovudine Increased cardiotoxicity ● Anthracyclines ● Cytarabine ● Pentostatin ● Radiation therapy of the cardiac region ● Trastuzumab Increased pulmonary toxicity ● Amiodarone ● G-CSF, GM-CSF (granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor) Increased nephrotoxicity ● Amphotericin B ● Indomethacin:
Cyclophosphamide label (Eugia US LLC, April 21, 2025), drug interactionsNatalizumab Paclitaxel: Increased hematotoxicity has been reported when cyclophosphamide was administered after paclitaxel infusion.
Source: FDA drug label (Frindovyx, NDA210852), AVYXA Pharma, LLC, effective August 26, 2026 (SPL set 5ad8ea65-4c98-487a-9c8d-df778765ec5e), via openFDA
Source: FDA drug label (Cyclophosphamide, NDA210735), Eugia US LLC, effective April 21, 2025 (SPL set 3c1eb470-0bba-457d-94e3-b9508f0d398a), via openFDA
Source: FDA drug label (Cyclophosphamide), Amneal Pharmaceuticals LLC, effective January 19, 2026 (SPL set 520bfe39-dfd5-4a20-9a37-80078afded0d), via openFDA; the full label on DailyMed
What does the paclitaxel label say about cyclophosphamide?
Paclitaxel's label (effective January 21, 2026) and its 3 other brand-application labels do not name cyclophosphamide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Paclitaxel), Natco Pharma USA LLC, effective January 21, 2026 (SPL set a1eb16b4-285b-4e81-9c4e-1244d4a52af8), 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
| Cyclophosphamide | Paclitaxel | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Breast cancer, Lung cancer |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.67 per capsule 50 mg 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