Cyclophosphamide Injection, Solution Interactions

• 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: Acute water intoxication has been reported with concomitant use of indomethacin Increase in other toxicities: • Azathioprine: Increased risk of hepatotoxicity (liver necrosis) • Busulfan: Increased incidence of hepatic veno-occlusive disease and mucositis has been reported.

Source: FDA drug label - cyclophosphamide injection, solution

• 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: Acute water intoxication has been reported with concomitant use of indomethacin Increase in other toxicities: • Azathioprine: Increased risk of hepatotoxicity (liver necrosis) • Busulfan: Increased incidence of hepatic veno-occlusive disease and mucositis has been reported.

Source: FDA drug label - cyclophosphamide injection, solution

7 DRUG INTERACTIONS 7.1 Effect of Other Drugs on Cyclophosphamide Exposure Protease Inhibitors Cyclophosphamide is a pro-drug that is activated by cytochrome P450s [see Clinical Pharmacology (12.3) ]. Use of protease inhibitor-based regimens was found to be associated with a higher Incidence of infections and neutropenia in patients receiving cyclophosphamide, doxorubicin, and etoposide (CDE) than use of a Non-Nucleoside Reverse Transcriptase Inhibitor-based regimen. 7.2 Drugs that Can Potentiate Cyclophosphamide Toxicities Combined or sequential use of Cyclophosphamide Injection and other drugs or agents with similar toxicities to Cyclophosphamide Injection and can potentiate these effects and are listed in Table 2 .

Source: FDA drug label - cyclophosphamide injection, solution

Metronidazole Acute encephalopathy has been reported in a patient receiving cyclophosphamide and metronidazole. In an animal study, the combination of cyclophosphamide with metronidazole was associated with increased cyclophosphamide toxicity.

Source: FDA drug label - cyclophosphamide injection, solution

• Natalizumab • Paclitaxel: Increased hematotoxicity has been reported when cyclophosphamide was administered after paclitaxel infusion.

Source: FDA drug label - cyclophosphamide injection, solution