Double-blind Crossover Study (double-blind + crossover_study)

Distribution by Scientific Domains


Selected Abstracts


Characterization of aggressive behavior and phenytoin response

AGGRESSIVE BEHAVIOR, Issue 1 2006
Rebecca J. Houston
Abstract Recent work has suggested that the success of pharmacological treatment for chronic aggressive behavior may depend, in part, on the subtype of aggressive behavior displayed (e.g. reactive, impulsive aggression vs. predatory, premeditated aggression). The present study examined the usefulness of characterizing aggressive behavior during a 16-week double-blind crossover study of phenytoin (PHT) treatment in 41 aggressive adult males. The Impulsive/Premeditated Aggression Scales (IPAS) were used to characterize aggressive behavior as predominantly impulsive or predominantly premeditated in nature. Analyses indicated that participants who did not respond to PHT treatment endorsed significantly more premeditated characteristics on the IPAS than those who responded to PHT treatment. Non-responders also exhibited fewer aggressive outbursts during placebo treatment, suggesting a greater level of behavior control. Participants who did not complete the study were younger, endorsed significantly more premeditated aggression characteristics and reported more lifetime antisocial behaviors than those who completed the study. Taken together, these data emphasize several factors that may influence the success of pharmacological treatment in aggressive individuals, namely the importance of characterizing the predominant type of problem aggressive behavior. Aggr. Behav. 00:1,6, 2005. © 2005 Wiley-Liss, Inc. [source]


Ultrasonographic guided axillary plexus blocks with low volumes of local anaesthetics: a crossover volunteer study

ANAESTHESIA, Issue 3 2010
P. Marhofer
Summary Our study group recently evaluated an ED95 local anaesthetic volume of 0.11 ml.mm,2 cross-sectional nerve area for the ulnar nerve. This prospective, randomised, double-blind crossover study investigated whether this volume is sufficient for brachial plexus blocks at the axillary level. Ten volunteers received an ultrasonographic guided axillary brachial plexus block either with 0.11 (,low' volume) or 0.4 (,high' volume) ml.mm,2 cross-sectional nerve area with mepivacaine 1%. The mean (SD) volume was in the low volume group 4.0 (1.0) and 14.8 (3.8) ml in the high volume group. The success rate for the individual nerve blocks was 27 out of 30 in the low volume group (90%) and 30 out of 30 in the high volume group (100%), resulting in 8 out of 10 (80%) vs 10 out of 10 (100%) complete blocks in the low vs the high volume groups, respectively (NS). The mean (SD) sensory onset time was 25.0 (14.8) min in the low volume group and 15.8 (6.8) min in the high volume group (p < 0.01). The mean (SD) duration of sensory block was 125 (38) min in the low volume group and 152 (70) min in the high volume group (NS). This study confirms our previous published ED95 volume for mepivacaine 1% to block peripheral nerves. The volume of local anaesthetic has some influence on the sensory onset time. [source]


Randomized Double-blind Placebo Controlled Crossover Study of Acetaminophen, Ibuprofen, Acetaminophen/Hydrocodone, and Placebo for the Relief of Pain From a Standard Painful Stimulus

ACADEMIC EMERGENCY MEDICINE, Issue 9 2009
James R. Miner MD
Abstract Objectives:, The objective was to compare subjects' change in perceived acute pain from an identical painful stimulus after receiving three separate, commonly used pain medications and placebo. Methods:, This was an institutional review board,approved, randomized, double-blind crossover study of healthy human volunteers. Subjects received 1000 mg of acetaminophen, 800 mg of ibuprofen, the combination of 650 mg of acetaminophen with 10 mg of hydrocodone, or placebo (800 mg of lactose) in a randomized order over four separate occasions each 1 week apart. Prior to receiving the drug on each study day, subjects placed their nondominant hand in a bath of 0°C water for 45 seconds. The bath was divided into two sections; the larger was the reservoir of cooled water monitored at 0°C, and the other half was filled from constant overflow. Water drained from the overflow section into the cooling unit and was then pumped up into the base of the reservoir through a diffusion grid. Subjects completed a 100-mm visual analog scale (VAS) representing perceived pain during the exposure. The cold water exposure and VAS were repeated 1 hour after receiving the study drug, and then subjects were observed for side effects for 4 hours. Data were compared using descriptive statistics, 95% confidence intervals (CIs), and repeated-measures analysis of variance (ANOVA). Results:, Twenty-five subjects were enrolled. The mean VAS preexposure was 56.9 mm (±15.1 mm; range = 5 to 92 mm). The mean decrease in VAS after receiving the study drug for acetaminophen was 10.2% (95% CI = ,1.4 to 20.4), for ibuprofen was ,6.6% (95% CI = ,16.5 to 3.20), for acetaminophen/hydrocodone was 9.5% (95% CI = 1.4 to 20.4), and for placebo was ,6.9% (95% CI = ,15.2 to 1.4). The range in change in pain scores for all agents was ,91.3% to 57.6%. Mild side effects (nausea, dizziness, or somnolence) were reported in 11 subjects (44%) after receiving acetaminophen/hydrocodone; no other side effects were reported. Conclusions:, There was a wide range of changes in pain scores from this identical painful stimulus after receiving the study medications. Acetaminophen and acetaminophen/hydrocodone resulted in a similar decrease in pain (10.2 and 9.5%), while ibuprofen and placebo had a similar lack of effect (,6.6 and ,6.9%). Forty-four percent of subjects receiving acetaminophen/hydrocodone reported mild side effects; no other side effects were seen. In this noninflammatory pain model, the VAS is not able to distinguish differences in pain relief between acetaminophen and acetaminophen/hydrocodone or ibuprofen and placebo. [source]


Pathological gambling in Parkinson disease is reduced by amantadine

ANNALS OF NEUROLOGY, Issue 3 2010
Astrid Thomas MD
To investigate the possible efficacy of amantadine in the control of pathological gambling (PG) associated with Parkinson disease (PD), 17 PD patients with PG were randomly selected for a double-blind crossover study with amantadine 200mg/day versus placebo and an open follow-up. Assessments included PG-specific scales (Yale-Brown Obsessive-Compulsive Scale for PG, Gambling-Symptom Assessment Scale, South Oaks Gambling Screen) and assessment of expenditures and time spent gambling. Amantadine abolished or reduced PG in all treated patients, as confirmed by scale score and daily expenditure reduction. Amantadine might be useful to treat PG. The effect of amantadine, acting as an antiglutamatergic agent, also opens new insights into the pathogenesis of PG. ANN NEUROL 2010 [source]


Influence of short-term exposure to airborne Der p 1 and volatile organic compounds on skin barrier function and dermal blood flow in patients with atopic eczema and healthy individuals

CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2006
J. Huss-Marp
Summary Background Epidemiological studies indicate environmental pollutants to be involved in the increase in the prevalence of allergic diseases. In human exposure studies, volatile organic compounds (VOCs) have been shown to cause exacerbations of allergic asthma whereas, no data concerning atopic eczema (AE) are available. Objective We investigated the effect of airborne VOCs on the skin of patients with AE and controls in the presence or absence of house dust mite allergen, Der p 1. Methods In a double-blind crossover study, 12 adults with AE and 12 matched healthy volunteers were exposed on their forearms to Der p 1 and subsequently to a mixture of 22 VOCs (M22, 5 mg/m3) in a total body exposure chamber for 4 h. Transepidermal water loss (TEWL) and skin blood flow were measured in all subjects before, during and after exposure. Additionally, an atopy patch test (APT) with Der p 1 was applied to the skin after exposure. Results A significant increase in transepidermal water loss was observed 48 h after exposure to VOCs as compared with exposure with filtered air in all individuals (mean difference: +34%; 95% Confidence Interval: 7,69%). Prior Der p 1 exposure resulted in a significant rise of dermal blood flow after 48 h in patients with AE but not in controls. Six out of seven patients showed enhanced atopy patch test (APT) reactions to HDM allergen after previous exposure to VOCs. Conclusion Our results show that exposure to VOCs , at concentrations commonly found in indoor environments , can damage the epidermal barrier and enhance the adverse effect of Der p 1 on sensitized subjects with AE. These findings may contribute to a better understanding of the mechanisms underlying the increase in prevalence and exacerbation of AE. [source]