Initial evaluation of N,N-diethyl-m-toluamide and permethrin absorption in human volunteers under stress conditions.
OBJECTIVE
This was a pilot study to determine (1) whether it is feasible to effectively blind human subjects to the presence of the insect repellents N,N-diethyl-m-toluamide (DEET) and permethrin; (2) whether DEET affects the absorption of permethrin; and (3) whether combat videotape viewing and mental arithmetic are stressful.


METHODS
Ten volunteers were exposed to DEET, permethrin, and stress (1-hour combat videotape plus mental arithmetic) in a double-blind, randomized, placebo-controlled trial. Outcome measurements included hemodynamics, plasma DEET and permethrin levels, and questionnaires to assess blinding.


RESULTS
Highly sensitive serologic assays readily detected DEET but not permethrin. Staff members and subjects were effectively blinded to both. The videotape-math combination was stressful by both self-report and hemodynamic measures.


CONCLUSIONS
It is possible to blind subjects with respect to DEET and permethrin. Permethrin on clothing does not enter the bloodstream at appreciable levels. Combat videotapes and mental arithmetic can be stressful.
Roy
Michael J
MJ
Department of Medicine, Division of Military Internal Medicine, Room A3062, Uniformed Services University, Bethesda, MD 20814, USA.
Kraus
Patricia L
PL
Cooper
Jamie A
JA
Cherstniakova
Svetlana
S
Coll
Regina
R
Seegers
Cynthia A
CA
Deuster
Patricia A
PA
Koslowe
Patricia
P
Law
Wendy A
WA
Krantz
David S
DS
Cantilena
Louis
L
D000328:Adult; D018592:Cross-Over Studies; D003671:DEET / Q000097:blood*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007302:Insect Repellents / Q000097:blood*; D016014:Linear Models; D008297:Male; D026023:Permethrin / Q000097:blood*; D010865:Pilot Projects; D012869:Skin Absorption; D013315:Stress, Psychological / Q000503:physiopathology*
D007302:Insect Repellents; D003671:DEET; D026023:Permethrin