Continuous infusion of piperacillin-tazobactam provided clinical and microbiologic outcomes equivalent to those for intermittent infusion. Compared with intermittent infusion, continuous infusion significantly shortened the time to temperature normalization, while also offering a significant reduction in level 2 expenditures.

Principles of antibiotic pharmacodynamics include factors that are important for effective eradication of bacteria as well as the suppression of resistance. For effective eradication of bacteria and a good clinical outcome, a ratio for the area under the plasma concentration-time curve relative to the minimum inhibitory concentration (AUC/MIC) of greater than 100 is needed for gram-negative organisms, and a level of greater than 30 is required for gram-positive organisms. Pharmacodynamic principles can also be used to devise the optimal administration regimen for specific antimicrobial agents. Pharmacodynamic analysis of the activity of levofloxacin against Streptococcus pneumoniae revealed that, 99% of the time, actual hospitalized patients achieve an AUC/MIC of greater than 30. This indicates that levofloxacin will be very effective in treating S. pneumoniae infections in the majority of patients. Cost of treatment is an increasing concern voiced by healthcare providers and users alike. This has led to a much greater emphasis placed upon the cost of individual drugs used in the management of infections. However, when evaluating the cost of an antibiotic, it is extremely important that not only are the direct acquisition costs assessed, but consideration also given to other aspects incurring a financial burden, such as drug preparation cost, supplies, costs of treating adverse events or any treatment failures. It is only by having such a full assessment of costs that realistic financial comparisons can be made between different antibiotics.

Background Infectious diarrhea is a common problem among travelers. Expert guidelines recommend the prompt use of antibiotics for self-treatment of moderate or severe traveler’s diarrhea (TD). There is limited data on whether travelers follow these self-treatment guidelines. We evaluated the risk factors associated with TD, use of TD self-treatment, and risk of irritable bowel syndrome (IBS) during travel. Methods Department of Defense beneficiaries traveling outside the US for ≤ 6.5 months were enrolled in a prospective cohort study. Participants received pre- and post-travel surveys, and could opt into a travel illness diary and follow-up surveys for symptoms of IBS. Standard definitions were used to assess for TD and IBS. Sub-optimal self-treatment was defined as use of antibiotics (with or without antidiarrheal agents) for mild TD, or use of antidiarrheals alone or no self-treatment in cases of moderate or severe TD. Results Twenty-four percent of participants (270/1120) met criteria for TD. The highest incidence was recorded in Africa (8.6 cases/100 person-weeks, 95% CI: 6.7–10.5). Two hundred and twelve TD cases provided information regarding severity and self-treatment: 89 (42%) had mild TD and 123 (58%) had moderate or severe TD. Moderate or severe TD was independently associated with suboptimal self-treatment (OR 10.4 [95% CI: 4.92–22.0]). Time to last unformed stool did not differ between optimal and suboptimal self-treatment. IBS occurred in 4.5% (7/154) of TD cases and 3.1% (16/516) of patients without TD (p=0.39). Among TD cases, a lower incidence of IBS was noted in participants who took antibiotics (4.8% (5/105) vs. 2.2% (1/46)), but the difference did not reach statistical significance (p=0.60). Conclusions Our results suggest the underutilization of antibiotics in travelers with moderate or severe TD. Further studies are needed to systematically evaluate pre-travel instruction and traveler adherence to self-treatment guidelines, and the impact of suboptimal self-treatment on outcomes.

Recent studies have collected high-dimensional data longitudinally. Examples include brain images collected during different scanning sessions and time-course gene expression data. Because of the additional information learned from the temporal changes of the selected features, such longitudinal high-dimensional data, when incorporated with appropriate statistical learning techniques, are able to more accurately predict disease status or responses to a therapeutic treatment. In this article, we review recently proposed statistical learning methods dealing with longitudinal high-dimensional data.