Cyclophosphamide and Darunavir interaction
Cyclophosphamide and Darunavir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Darunavir (PREZISTA) label · effective 2025-08-29
Immunosuppressant/neoplastic: everolimus Co-administration of everolimus and PREZISTA/ritonavir is not recommended. irinotecan Discontinue PREZISTA/ritonavir at least 1 week prior to starting irinotecan therapy.
Immunosuppressants : e.g. cyclosporine, tacrolimus, sirolimus ↑ immunosuppressants Therapeutic concentration monitoring of the immunosuppressive agent is recommended when co-administered with PREZISTA/ritonavir.
From the Cyclophosphamide (Frindovyx) label · effective 2026-08-26
Effect of Other Drugs on Cyclophosphamide Exposure Protease Inhibitors Concomitant use of protease inhibitors may increase the concentration of cytotoxic metabolites and may enhance the toxicities of cyclophosphamide, including higher incidence of infections, neutropenia, and mucositis.
Monitor for increased toxicities in patients receiving protease inhibitors.
…toxicities: ● Azathioprine: Increased risk of hepatotoxicity (liver necrosis) ● Busulfan: Increased incidence of hepatic veno-occlusive disease and mucositis has been reported. ● Protease inhibitors: Increased incidence of mucositis Increased risk of hemorrhagic cystitis ● Radiation treatment: Increased risk of hemorrhagic cystitis may result from a combined…
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.