title: Pharmacokinetics of intranasal alfentanil.
abstract: OBJECTIVE
  To determine the pharmacokinetics of intranasal and intravenous (IV) administrations of alfentanil in 10 healthy volunteers.
  
  
  METHODS
  Randomized, prospective, double-blind, placebo-controlled, cross-over trial with at least one week between the two modes of administration.
  
  
  METHODS
  Healthy volunteers at a university medical center.
  
  
  METHODS
  10 healthy, nondrug-dependent volunteers.
  
  
  METHODS
  Alfentanil 0.54 mg was administered either intranasally [with 12 ml of sodium chloride (NaCl) 0.9% IV] or IV (with 12 sprays of NaCl 0.9% intranasally). Each subject was assigned once to the intranasal and once to the IV group. To guarantee a complete elimination of alfentanil, there was a time period of at least one week between the different modes of administration.
  
  
  RESULTS
  Venous blood was sampled from a cubital vein at 3, 6, 9, 12, 15, 20, 30, 60, and 120 minutes after administration. Alfentanil plasma concentrations were determined by radioimmunoassay. Maximal plasma concentrations were 20.1 ng/ml +/- 7.3 ng/ml after 9 minutes in the intranasal group. At this measurement point, the intranasal alfentanil concentrations were 64.7% (18.7 ng/ml +/- 6.8 ng/ml) of the IV concentrations (28.9 ng/ml +/- 7.9 ng/ml). The calculated bioavailability after intranasal administration was 64.96% +/- 26.3%.
  
  
  CONCLUSIONS
  This pharmacokinetic study demonstrates a rapid rise in plasma concentrations, as well as a high bioavailability, following the intranasal administration of alfentanil.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Benjamin Franklin Medical Center, Free University of Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schwagmeier
authors.forename: N
authors.initials: N
authors.lastname: Boerger
authors.forename: W
authors.initials: W
authors.lastname: Meissner
authors.forename: H W
authors.initials: HW
authors.lastname: Striebel
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D004311:Double-Blind Method; D005260:Female; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D011446:Prospective Studies
chemical_list: D015760:Alfentanil