CYTOXAN

Cyclophosphamide is a prodrug. Cyclophosphamide pharmacokinetics are linear over the approved recommended dose range.

DistributionThe volume of distribution of cyclophosphamide is 30 to 50 L. Cyclophosphamide is approximately 20% protein bound, with no dose dependent changes. Some metabolites are greater than 60% protein bound.

EliminationThe elimination half-life (t½) of cyclophosphamide ranges from 3 to 12 hours, and clearance (CL) ranges from 4 to 5.6 L/h. When cyclophosphamide was administ...

The following adverse reactions are discussed in more detail in other sections of the labeling. Hypersensitivity [see Contraindications ( 4 )] Myelosuppression, Immunosuppression, Bone Marrow Failure, and Infections [see Warnings and Precautions ( 5.1 )] Urinary Tract and Renal Toxicity [see Warnings and Precautions ( 5.2 )] Cardiotoxicity [see Warnings and Precautions ( 5.3 )] Pulmonary Toxicity [see Warnings and Precautions ( 5.4 )] Secondary Malignancies [see Warnings and Precautions ( 5.5 )]...

Hypersensitivity Cyclophosphamide for injection is contraindicated in patients who have a history of severe hypersensitivity reactions to cyclophosphamide, any of its metabolites, or to other components of the product. Anaphylactic reactions including death have been reported with cyclophosphamide. Cross-sensitivity with other alkylating agents can occur. Urinary Outflow Obstruction Cyclophosphami...

Myelosuppression, Immunosuppression, Bone Marrow Failure and Infections: Severe immunosuppression may lead to serious and sometimes fatal infections. Close hematological monitoring is required. ( 5.1 ) Urinary Tract and Renal Toxicity: Hemorrhagic cystitis, pyelitis, ureteritis, and hematuria can occur. Urotoxicity can be fatal. Exclude or correct any urinary tract obstructions prior to treatment. ( 5.2 ) Cardiotoxicity: Myocarditis, myopericarditis, pericardial effusion, arrythmias and congesti...

7 DRUG INTERACTIONS 7.1 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. 7.2 Drugs th...