title: Enantioselectivity in the Metabolism of Cyclophosphamide in Patients With Multiple or Systemic Sclerosis.
abstract: The aim of this study was to evaluate the enantioselective pharmacokinetics of cyclophosphamide and its metabolites 4-hydroxycyclophosphamide and carboxyethylphosphoramide mustard in patients with systemic or multiple sclerosis. Patients with systemic sclerosis (n = 10) or multiple sclerosis (n = 10), genotyped for the allelic variants of CYP2C9*2 and CYP2C9*3 and of the CYP2B6 G516T polymorphism, were treated with 50 mg cyclophosphamide/kg daily for 4 days. Serial blood samples were collected up to 24 hours after administration of the last cyclophosphamide dose. Cyclophosphamide, 4-hydroxycyclophosphamide, and carboxyethylphosphoramide enantiomers were analyzed in plasma samples using liquid chromatography-tandem mass spectrometry coupled to chiral column Chiralcel OD-R or Chiralpak AD-RH. Cytokines IL-2, IL-4, IL-6, IL-8, IL-10, IL- 12p70, IL-17, TNF-α, and INT-δ in the plasma samples collected before cyclophosphamide infusion were analyzed by Milliplex MAP human cytokine/chemokine. Pharmacokinetic parameters showed higher plasma concentrations of (S)-(-)-cyclophosphamide (AUC 215.0 vs 186.2 μg·h/mL for multiple sclerosis patients and 219.1 vs 179.2 μg·h/mL for systemic sclerosis patients) and (R)-4-hydroxycyclophosphamide (AUC 5.6 vs 3.7 μg·h/mL for multiple sclerosis patients and 6.3 vs 5.6 μg·h/mL for systemic sclerosis patients) when compared to their enantiomers in both groups of patients, whereas the pharmacokinetics of the carboxyethylphosphoramide metabolite was not enantioselective. Cytokines' plasma concentrations were similar between multiple and systemic sclerosis groups. The pharmacokinetics of cyclophosphamide is enantioselective in patients with systemic sclerosis and multiple sclerosis, with higher plasma concentrations of the (S)-(-)-cyclophosphamide enantiomer due to the preferential formation of the (R)-4-hydroxycyclophosphamide metabolite.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Francine Attié
authors.initials: FA
authors.lastname: de Castro
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Belinda Pinto
authors.initials: BP
authors.lastname: Simões
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Eduardo Barbosa
authors.initials: EB
authors.lastname: Coelho
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Vera Lucia
authors.initials: VL
authors.lastname: Lanchote
mesh_terms: D000328:Adult; D003520:Cyclophosphamide / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D065702:Cytochrome P-450 CYP2B6 / Q000235:genetics; D065729:Cytochrome P-450 CYP2C9 / Q000235:genetics; D016207:Cytokines / Q000097:blood; D005260:Female; D005838:Genotype; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D012595:Scleroderma, Systemic / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D016207:Cytokines; D007166:Immunosuppressive Agents; D003520:Cyclophosphamide; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6
keywords: cyclophosphamide enantiomers; metabolism; multiple sclerosis; pharmacokinetics; systemic sclerosis