The efficacy of low-dose intranasal scopolamine for motion sickness.
BACKGROUND
Scopolamine is an effective motion sickness prophylactic, but oral and transdermal formulations are slowly absorbed. To enhance absorption and potentially efficacy, an intranasal formulation of scopolamine (INSCOP) was tested.


METHODS
There were 16 motion sickness susceptible subjects with an average age of 23.5 +/- 3.0 yr and an average score of 11.3 +/- 4.7 on the Modified Motion Sickness Susceptibility Questionnaire-Short Form who volunteered to participate in the study. Each subject was given 0.4 mg of INSCOP and a placebo in a randomized, double-blind crossover design and, at 40 min post-dose, experienced Coriolis cross-coupling in a staircase progression until moderate nausea. Efficacy data and cognitive, physiological, and alertness assessments were collected during baseline control and throughout experimental testing.


RESULTS
Intranasal scopolamine significantly increased the mean number of head movements tolerated [INSCOP 275.9 +/- 120.5, Placebo 230.7 +/- 76.4; t (15) = 2.21]. Estimation of medication absorption via plasma concentration indicated the drug was absorbed relatively rapidly to measurable levels by 15 min post-administration. Diastolic blood pressures and heart rate were significantly lower after administration of INSCOP compared to placebo. No significant cognitive or medication side effects were reported. Subjects reported no significant decrease in alertness as indicated by the Karolinska Sleepiness Scale.


CONCLUSIONS
Results of the current study strongly suggest that intranasal scopolamine is efficacious for the treatment of motion sickness in susceptible individuals with no significant cognitive or sedative effects. Intranasal delivery offers a promising alternative for use in dynamic operational environments without cognitive detriment or increased side effects.
Simmons
Rita G
RG
Naval Aerospace Medical Research Laboratory, 280 Fred Bauer Street, Building 1811, Pensacola, FL 32508, USA. rita.simmons@med.navy.mil
Phillips
Jeffrey B
JB
Lojewski
Renee A
RA
Wang
Zuwei
Z
Boyd
Jason L
JL
Putcha
Lakshmi
L
D000281:Administration, Intranasal; D015992:Body Mass Index; D018680:Cholinergic Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D003312:Coriolis Force; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006305:Health Status Indicators; D006339:Heart Rate; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000188:drug therapy*; D012307:Risk Factors; D012601:Scopolamine / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D012894:Sleep Stages; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
D018680:Cholinergic Antagonists; D012601:Scopolamine