Pharmacokinetics of intranasal alfentanil.
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.
Schwagmeier
R
R
Department of Anesthesiology and Intensive Care Medicine, Benjamin Franklin Medical Center, Free University of Berlin, Germany.
Boerger
N
N
Meissner
W
W
Striebel
H W
HW
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
D015760:Alfentanil