Comparative Pharmacology
Head-to-head clinical analysis: CYTOXAN versus MELPHALAN HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYTOXAN versus MELPHALAN HYDROCHLORIDE.
CYTOXAN vs MELPHALAN HYDROCHLORIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Cyclophosphamide is an alkylating agent that crosslinks DNA, leading to cell cycle nonspecific cytotoxicity. It requires hepatic activation by cytochrome P450 enzymes to form active metabolites, primarily phosphoramide mustard.
Melphalan is a bifunctional alkylating agent that forms cross-links between DNA strands, inhibiting DNA replication and transcription. It is cell cycle phase-nonspecific.
500-1500 mg/m² IV every 2-4 weeks or 1-5 mg/kg/day PO for 10-14 days.
16 mg/m² intravenously over 15-20 minutes every 2 weeks for 4 doses, then every 4 weeks
None Documented
None Documented
Terminal elimination half-life of cyclophosphamide is 3-12 hours (range 2-19 h) in adults; the half-life of active metabolites (e.g., 4-hydroxycyclophosphamide) is approximately 8-10 hours. Half-life is prolonged in hepatic impairment (up to 20 h) and reduced in dose adjustments.
1.5-2.5 h (terminal) in normal renal function; may be prolonged in renal impairment.
Renal elimination of unchanged cyclophosphamide (5-30%) and metabolites (primarily 4-ketocyclophosphamide and carboxyphosphamide) accounts for approximately 80% of total clearance; fecal excretion is minimal (<5%).
Renal: 10-30% unchanged; fecal: 20-30% as metabolites; biliary: minor.
Category C
Category D/X
Alkylating Agent
Alkylating Agent