title: Determination of cyclophosphamide in urine, serum and cerebrospinal fluid of multiple sclerosis patients by field desorption mass spectrometry.
abstract: The levels of cyclophosphamide in samples of urine, serum and cerebrospinal fluid of multiple sclerosis patients, who had received the drug orally (4 x 100 mg/day) have been determined by field desorption mass spectrometry using the principle of stable isotope dilution. After thorough preparation of the samples, concentrations of cyclophosphamide of 10 to 60 micrograms/ml in urine and 200 to 400 ng/ml in serum and cerebrospinal fluid have been determined from 0.6-3 ml samples. The first quantitative data for cyclophosphamide in cerebrospinal fluid of multiple sclerosis patients could be established without the use of radioactive material. The relatively high level of the parent drug found in the fluid at the end of a 3-weeks treatment may shed some light on the mechanism of action of this drug in the treatment of the disease.
mesh_terms: D003520:Cyclophosphamide / Q000097:blood / Q000134:cerebrospinal fluid / Q000627:therapeutic use / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D009103:Multiple Sclerosis / Q000097:blood / Q000134:cerebrospinal fluid / Q000188:drug therapy / Q000652:urine*
chemical_list: D003520:Cyclophosphamide