Prevalence and socioeconomic factors in the prescription of concurrent amphetamine and alprazolam.

OBJECTIVE: Goals were to determine the prevalence of concurrent prescription of amphetamine and alprazolam, and examine variation by socioeconomic factors. METHODS: Washington State's Prescription Monitoring Program was reviewed for calendar years 2013 through 2017. Individuals receiving more than 180 days of amphetamine, alprazolam or both were tabulated for each zip code. Prescription rates were compared between zip codes with variation in rural/urban setting and fraction of low and high income households using a multiple regression. RESULTS: One in 3920 individuals in the general population of Washington State were taking a combination of alprazolam and amphetamine. The statewide prevalence of this combination increased 40.2% between 2013 and 2017. The prevalence of the combination in each zip code is significantly positively correlated with the fraction of high income households, p < 0.001, and urban area, p < 0.05. In contrast, the prevalence of amphetamine increased with both the fraction of high income, p < 0.001, and low income households, p < 0.01, with an incremental increase over twice as large with fraction of high income (b = 232 (25)) than low income households (b = 102 (38)). In contrast, alprazolam decreased in prevalence with the fraction of high income households, p < 0.05. CONCLUSIONS: The prevalence of concurrent prescription of alprazolam and amphetamine correlates with local socioeconomic factors, including greater household income, instead of the prevalence of FDA indications, including anxiety disorders or ADHD. More clinical studies are required to establish efficacy and guidelines for safe use to mitigate the increased risk of accidents in patients taking concurrent amphetamine and alprazolam.

Relative prevalence of 10 types of pharmacodynamic interactions in psychiatric treatment.

Objective: To assess the relative prevalence and factors affecting the prescription of medication combinations with a theoretical efficacy limiting pharmacodynamic interaction, defined as two medications with opposing indications and side effects or antagonistic action at the primary receptor of mechanism of action. Method: One hundred sixteen combinations were identified for 10 types of pharmacodynamic interactions. PubMed was searched for each combination to assess the quality of evidence either supporting clinical use or verifying reduced efficacy. Micromedex was searched to determine the presence of warnings to prescribers of reduced efficacy. The prevalence in clinical practice was determined by computer review of the Genoa Healthcare database for all prescribers at 10 participating community mental health centers. The expected prevalence was calculated as the product of the probability of each medication prescribed alone and was compared with the actual prevalence of the combination using the test of proportions. Results: The frequency of prescription of eight combinations met the Bonferroni corrected level of significance of p < 0.001. Four were combinations of amphetamine and D2 antagonists and each were prescribed less often than chance, p = 0.0001 consistent with epidemiological studies and multiple animal studies verifying an efficacy limiting interaction. Despite epidemiological studies indicating increased risk of accidents, alprazolam and amphetamine were prescribed more often than chance, p = 0.0001. Micromedex generated warnings for efficacy limiting interactions for five other combinations, but with no subsequent change in prescription frequency. Conclusions: Neither presence of medical evidence nor warnings from Micromedex consistently affect the prescription of combinations with pharmacodynamic efficacy limiting interactions.

Hotel Room Suicide: Cuyahoga, Orange, Travis, and Wayne Counties.

OBJECTIVE: To compare the suicide rates of local residents registering in local hotels with the general suicide rate in that county and to compare the suicide rates of hotel guests from outside the county with the national suicide rate. METHODS: The numbers of cases of suicide in hotel rooms and the general community were tabulated for Cuyahoga County, Ohio, for calendar years 2010-2017; in Orange County, California, and Travis County, Texas, for 2010-2012; and in Wayne County, Michigan, for 1997 to March 2005. The percentage of local residents registering in local hotel rooms was estimated from various sources to stratify the suicide risk for travelers and local residents. RESULTS: The suicide rate of local residents registering in local hotels was elevated compared to the general nonhotel population in each county (range of relative risk, 15.1-37.8; P < .0001, Poisson distribution). Hotel guests from outside each county had a reduced rate of suicide compared to the national rate (range of relative risk, 0.124-0.524; P < .05, Poisson distribution). With regard to suicide method, drug overdoses accounted for a significantly greater percentage in hotel rooms than in the nonhotel population in 3 of 4 counties (range of risk ratios, 2.03-4.51, P < .01; test of proportions), with the opposite pattern for gunshot wounds (range of risk ratios, 0.27-0.50; P < .01, test of proportions). CONCLUSIONS: Although local residents register in hotels for various reasons, there appears to be a subpopulation with a purpose of avoiding rescue. Consistent with the risk-rescue rating, means of suicide with lower lethality, eg, drug overdoses, account for a greater percentage of cases in a setting with less chance of rescue. In contrast to the local use population, the sense of purpose or meaning inherent in travel could explain the decreased risk of suicide in guests from outside the county.

Deblurring visual evoked potentials using commercially available software.

Visual evoked potentials are useful clinical tools to study visual pathways of the brain. Although the temporal resolution is unsurpassed by other brain imaging technologies, the spatial resolution is diminished or blurred by the low conductance of the electrical signals through the skull. Methods have been proposed to improve the spatial resolution by downwardly projecting the electrical signals measured on the scalp to the surface of the cerebral cortex through the inverse solution of the equations governing static current flow. We describe the adaptation and combination of commercially available engineering software programs to solve this inverse problem and report the results of a sample run of the system. Before deblurring, the visual evoked potentials appeared to be diffusely localized over the posterior scalp. After deblurring, the visual evoked potentials were only found at the electrodes closest to the visual cortex, as would be predicted by our current knowledge of neuroanatomy.