Pharmacokinetics of doxepin in subjects with pruritic atopic dermatitis.
BACKGROUND
Doxepin applied topically by itself or in combination with triamcinolone acetonide is a safe and effective treatment for atopic dermatitis.


OBJECTIVE
We evaluated the pharmacokinetic profile of doxepin and desmethyldoxepin after topical application of doxepin hydrochloride 5% cream alone or in combination with 0.025% triamcinolone acetonide (doxepin/TAC).


METHODS
Twenty-four subjects with atopic dermatitis received either doxepin or doxepin/TAC cream 4 times daily for 7 days in a randomized, double-blind, controlled trial. Serum samples were obtained and pharmacokinetic parameters estimated from the dose-normalized serum concentrations of doxepin and desmethyldoxepin. Efficacy and adverse experiences were determined by physician and subject evaluations.


RESULTS
Pharmacokinetic parameters (K(e ), t(1/2 ) and AUC) calculated in 9 subjects (doxepin/TAC = 4 subjects, doxepin = 5 subjects) with detectable serum concentrations were similar for both groups. Pruritus relief and lessening of pruritus severity were significantly greater with doxepin/TAC than doxepin alone.


CONCLUSIONS
Topically applied doxepin is safe and effective therapy for pruritus.
Drake
L A
LA
Dermatology Clinical Investigations Unit, Pediatric Psychopharmacology Unit, Boston, MA 02114-2696, USA.
Cohen
L
L
Gillies
R
R
Flood
J G
JG
Riordan
A T
AT
Phillips
S B
SB
Stiller
M J
MJ
D000287:Administration, Topical; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000982:Antipruritics / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D003876:Dermatitis, Atopic / Q000188:drug therapy*; D004311:Double-Blind Method; D004316:Doxepin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D009824:Ointments; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000627:therapeutic use
D000893:Anti-Inflammatory Agents; D000982:Antipruritics; D004338:Drug Combinations; D009824:Ointments; D004316:Doxepin; D014222:Triamcinolone Acetonide; C028701:desmethyldoxepin