What the FDA labels say about taking them together
Cyclophosphamide and etanercept
Cyclophosphamide's FDA label (Cyclophosphamide) of April 21, 2025 names etanercept in its drug interactions section, and etanercept's label names cyclophosphamide too. The etanercept label: “… Abatacept – Increased risk of serious adverse events, including infections Cyclophosphamide – Not recommended for use with Enbrel.”
Check it at the source: the cyclophosphamide FDA label on DailyMed (effective January 19, 2026, Amneal Pharmaceuticals LLC); the etanercept FDA label on DailyMed (effective May 11, 2026, Immunex Corporation).
What does the cyclophosphamide label say about etanercept?
Cyclophosphamide label (Eugia US LLC, April 21, 2025), drug interactionsCyclophosphamide on Other Drugs Etanercept A higher incidence of non-cutaneous malignant solid tumors in patients with Wegener’s granulomatosis occurred with the addition of etanercept to cyclophosphamide treatment.
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 etanercept label say about cyclophosphamide?
Etanercept label, drug interactionsLive vaccines – Avoid concurrent administration with Enbrel ( 5.8 , 7.1 ) Anakinra – Increased risk of serious infection ( 5.12 , 7.2 ) Abatacept – Increased risk of serious adverse events, including infections ( 5.12 , 7.2 ) Cyclophosphamide – Not recommended for use with Enbrel.
Etanercept label, warnings and precautionsIn a study of patients with granulomatosis with polyangiitis, the addition of Enbrel to standard therapy (including cyclophosphamide) was associated with a higher incidence of non-cutaneous solid malignancies and was not associated with improved clinical outcomes when compared with standard therapy alone [see Drug Interactions (7.3) ].
Source: FDA drug label (ENBREL), Immunex Corporation, effective May 11, 2026 (SPL set a002b40c-097d-47a5-957f-7a7b1807af7f), 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 | Etanercept | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Rheumatoid arthritis, Psoriasis |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.67 per capsule 50 mg capsule | $2,084.14 per mL 25 mg/0.5 mL syringe |
| 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