Adults

Highly variable and individualized based on the specific cancer or autoimmune condition, concomitant therapies, and patient's general health, typically administered intravenously. Dosage ranges from 50 mg/m² to 1500 mg/m² at various intervals (daily, weekly, monthly).

Elderly

Reduced doses may be necessary in elderly patients due to age-related decline in renal or hepatic function and increased susceptibility to myelosuppression.

Renal_impairment

Dose adjustment is required for patients with severe renal impairment (CrCl <20 mL/min). Generally, a 25-50% dose reduction may be necessary.

Onset

Onset of action varies based on the indication and dosage regimen, often days to weeks for therapeutic effect.

Excretion

Primarily excreted renally as unchanged drug and metabolites. Approximately 5-25% of the dose is excreted unchanged in urine.

Half life

Elimination half-life of cyclophosphamide is approximately 3 to 10 hours; active metabolites have a longer half-life.

Absorption

Rapidly and extensively absorbed after oral administration. IV administration ensures complete bioavailability.

Metabolism

Extensively metabolized in the liver by cytochrome P450 enzymes to active metabolites (e.g., phosphoramide mustard, acrolein) and inactive metabolites.

Warfarin

May alter the anticoagulant effect of warfarin, requiring close monitoring of INR.

Allopurinol

May increase bone marrow depression and cyclophosphamide toxicity.

Live vaccines

Increased risk of severe infection; avoid administration during cyclophosphamide therapy.

Phenobarbital

Can induce hepatic enzymes, potentially increasing the formation of active cyclophosphamide metabolites and toxicity.

Anthracyclines (e.g., Doxorubicin)

Increased risk of cardiotoxicity.