A pharmacokinetic and pharmacodynamic study, in healthy volunteers, of a rapidly absorbed intranasal midazolam formulation.
OBJECTIVE
To compare 2.5 mg and 5.0 mg single-dose pharmacokinetics (PK), pharmacodynamics (PD) and tolerability of an intranasal (i.n.) midazolam formulation, to a 2.5-mg intravenous (i.v.) dose.


METHODS
Design was an open-label, three-way crossover, randomized PK and PD study in seventeen healthy volunteers. Twelve-hour PK parameters were determined for each treatment arm. Subjects completed serial self-ratings for sedation and other drug effects. Nurse observers made serial observations for sedation and adverse effects. An otolaryngologist conducted a nasal endoscopy, pre-dose, 2-4 h, and at end of study, to examine the nasal cavity for formulation-induced changes in nasal anatomy.


RESULTS
Midazolam was rapidly absorbed following i.n. administration, with a median t(max) of 10 min; dose proportionate increases for C(max) and AUC; t(1/2) of 4 h; and, 60% (+/-23) nasal administration bioavailability compared to the i.v. dose. PD responses were rapid, paralleled the PK, and in magnitude was in a rank order of i.v. 2.5 mg > or = i.n. 5.0 mg > i.n. 2.5 mg doses. The formulation was well tolerated with no serious cardiovascular or respiratory complications. Fourteen subjects complained of at least one of the following: a brief and mild to moderate intensity facial flushing, nasal passage burning, sore throat or bad taste after drug administration. There were no adverse findings from the nasal endoscopic exam.


CONCLUSIONS
Dosages of an investigational i.n. midazolam formulation resulted in rapid absorption and attained plasma concentrations that correlated with pharmacodynamic effects.
Wermeling
Daniel P
DP
Department of Pharmacy Practice and Science,University of Kentucky College of Pharmacy, Lexington, KY 40536, United States. dwermel@uky.edu
Record
Kenneth A
KA
Archer
Sanford M
SM
Rudy
Anita C
AC
D000281:Administration, Intranasal; D000328:Adult; D000704:Analysis of Variance; D014151:Anti-Anxiety Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002853:Chromatography, Liquid; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008874:Midazolam / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D012890:Sleep / Q000187:drug effects; D013997:Time Factors; D055815:Young Adult
D014151:Anti-Anxiety Agents; D008874:Midazolam