title: [Subnormal vitamin B6 levels in theophylline users].
abstract: OBJECTIVE
  To study the effect of theophylline use on the vitamin B-6 status.
  
  
  METHODS
  Descriptive.
  
  
  METHODS
  Department of Geriatric Medicine of Nijmegen Academic Hospital and Department of Pulmonary Diseases, University of Nijmegen, the Netherlands.
  
  
  METHODS
  Vitamin B-6 status was determined by measuring pyridoxal-5'-phosphate (PLP) in whole blood (using a high performance liquid chromatography method, reference values: 35-107 mumol/l) in 141 patients from the Geriatric department (84 non-chronic obstructive pulmonary disease (COPD), 40 COPD patients without theophylline and 17 COPD patients with theophylline) and in 25 non-geriatric COPD patients on theophylline.
  
  
  RESULTS
  Of the 84 geriatric non-COPD patients (mean age: 82 years; SD: 6) 56% had a subnormal vitamin B-6 status, of the 40 geriatric COPD patients without theophylline (82 years; SD: 6) 70%, of the 17 geriatric COPD patients on theophylline (80 years; SD: 5) 94% and of the 25 non-geriatric COPD patients on theophylline (62 years; SD: 11) 96%.
  
  
  CONCLUSIONS
  In patients who used theophylline a higher prevalence of subnormal vitamin B-6 status was found than in patients who did not.
authors.affiliation: Afd. Geriatrie, Academisch Ziekenhuis, Nijmegen.
authors.forename: M G
authors.initials: MG
authors.lastname: Martinez de Haas
authors.forename: P J
authors.initials: PJ
authors.lastname: Poels
authors.forename: C J
authors.initials: CJ
authors.lastname: de Weert
authors.forename: C M
authors.initials: CM
authors.lastname: Thomas
authors.forename: J M
authors.initials: JM
authors.lastname: Rooyackers
authors.forename: W H
authors.initials: WH
authors.lastname: Hoefnagels
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004336:Drug Antagonism; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000188:drug therapy; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000097:blood; D012189:Retrospective Studies; D013806:Theophylline / Q000009:adverse effects* / Q000494:pharmacology; D026681:Vitamin B 6 Deficiency / Q000097:blood / Q000139:chemically induced*
chemical_list: D011732:Pyridoxal Phosphate; D013806:Theophylline