title: Correlation between plasma and urinary caffeine levels in preterm infants.
abstract: BACKGROUND
  We hypothesize that urine levels might be reliable to assess the therapeutic range of caffeine.
  
  
  OBJECTIVE
  We correlated plasma and urinary levels of caffeine in preterm infants treated with this drug for apnea of prematurity.
  
  
  METHODS
  Infants (n=56) were given a loading dose of caffeine citrate (10 mg/kg, per os) and 24 h later a maintenance dose (2 mg/kg, per os, once a day). Plasma and urinary levels of caffeine were determined 24 h after the loading dose (before administration of the maintenance dose) and then weekly.
  
  
  RESULTS
  Plasma and urinary levels correlate at all examined ages: 29 weeks (r=0.92, P<0.001), 30 weeks (r=0.97, P<0.001), 31 weeks (r=0.82, P<0.001), 32 weeks (r=0.92, P<0.001), 33 weeks (r=0.87, P<0.001), 34 weeks (r=0.81, P<0.001).
  
  
  CONCLUSIONS
  Urinary levels of caffeine might be a useful means to assess therapeutic ranges.
authors.affiliation: Department of Pediatrics, Ospedale Civile di Tolmezzo, Italy. resppedto@ass3.sanita.fvg.it
authors.forename: Luigi
authors.initials: L
authors.lastname: Cattarossi
authors.forename: Marco
authors.initials: M
authors.lastname: Violino
authors.forename: Franco
authors.initials: F
authors.lastname: Macagno
authors.forename: Paolo
authors.initials: P
authors.lastname: Logreco
authors.forename: Marilena
authors.initials: M
authors.lastname: Savoia
mesh_terms: D001049:Apnea / Q000097:blood* / Q000188:drug therapy / Q000652:urine*; D002110:Caffeine / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use / Q000652:urine*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male
chemical_list: D002110:Caffeine