What the FDA labels say about taking them together
Cyclophosphamide and zidovudine
Cyclophosphamide's FDA label (Frindovyx) of August 26, 2026 names zidovudine in its drug interactions section; the zidovudine labels PlainMeds reads (3) do not name cyclophosphamide. The cyclophosphamide label: “… cyclophosphamide was administered after paclitaxel infusion. Thiazide diuretics Zidovudine”
Check it at the source: the cyclophosphamide FDA label on DailyMed (effective January 19, 2026, Amneal Pharmaceuticals LLC); the zidovudine FDA label on DailyMed (effective February 10, 2025, Aurobindo Pharma Limited).
What does the cyclophosphamide label say about zidovudine?
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 interactionsToxicity: Increased hematotoxicity and/or immunosuppression; Drugs: ACE inhibitors: ACE inhibitors can cause leukopenia. Natalizumab Paclitaxel: Increased hematotoxicity has been reported when cyclophosphamide was administered after paclitaxel infusion. Thiazide diuretics Zidovudine
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 zidovudine label say about cyclophosphamide?
Zidovudine's label (effective February 10, 2025) and its 2 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 (Zidovudine), Aurobindo Pharma Limited, effective February 10, 2025 (SPL set 51abd2ce-6be1-412d-b806-5f24935ac5e3), 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 | Zidovudine | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.67 per capsule 50 mg capsule | $0.464 per tablet 300 mg tablet |
| 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