The concentration/MIC (C/MIC) ratio maximizing the bactericidal activity of ceftazidime against 10 Pseudomonas aeruginosa isolates from cystic fibrosis patients was identified. Bactericidal activity was assessed by determining the percent difference in the area under the killing curve at each C/MIC ratio for all of the isolates from that of their growth control. The percent effect at each C/MIC ratio was fitted to a sigmoidal Emax model with maximum bactericidal activity defined as the C/MIC ratio that produced an effect that was 90% of the Emax. Our results suggest that at least some isolates may require higher C/MIC ratios than previously reported for maximal activity.

Slow extended daily dialysis (SLEDD) is the newest form of dialysis that is being used increasingly to replace continuous venovenous hemodialysis (CVVHD) for critically ill patients; it is less expensive to administer and has similar safety for patients who are prone to hemodynamic instability. Unfortunately, there are limited data regarding the appropriate dosing of antimicrobial agents for patients undergoing SLEDD. Furthermore, many nonnephrologists are not familiar with the differences between SLEDD, other continuous renal replacement therapies--for example, CVVHD--and routine hemodialysis. Thus, there is potential for inaccurate and, at worst, inadequate dosing of critical antimicrobial agents for this patient population. We review the available pharmacokinetic data on SLEDD and give preliminary recommendations for how to approach dosing in this situation.

Current evidence suggests that controlling antibiotic resistance requires the monitoring of both susceptibility trends and antimicrobial usage within specific patient-care areas of the hospital. To assess the differences between antimicrobial usage-versus-susceptibility relationships found in the hospital and those relationships found in specific patient-care areas, susceptibility and antimicrobial usage data collected over a 5-year period (1992-1996) at the Medical University of South Carolina were analyzed. For each area, the relationship between drug use and susceptibility was analyzed for 8 gram-negative organisms with respect to 19 different agents and for 3 staphylococci with respect to 10 agents with use of simple linear regression. The relationships found in the hospital had a poorer overall agreement with the relationships found in the intensive care units (ICUs; <20%) than they did with the relationships found in the non-ICUs ( approximately 65%). Surveillance should include both susceptibility and drug usage patterns in individual areas within an institution.

Objectives. To assess the effectiveness, efficiency, and student satisfaction with computer-mediated instruction (CMI) versus lecture-mediated instruction (LMI) of pain management to doctor of pharmacy (PharmD) students. Methods. This study compared the instruction of pain management by CMI versus LMI. An examination was administered and a student survey was conducted to determine effectiveness and student perception of efficiency and satisfaction with these teaching methods.Results. Mean examination scores were not significantly different between the 2 groups, with 62 (91%) of the LMI group and 46 (94%) of the CMI group scoring $70% (p 5 0.73). Efficiency and student perception of learning significantly increased in the CMI group.Conclusions. CMI appears to be at least as effective as LMI in teaching pain management to pharmacy students and students perceive that efficiency and learning is increased with CMI. Therefore, CMI seems to be a viable teaching option.

Bactericidal activity, historically assessed by in vitro tests which employ fixed drug concentrations, may also be evaluated in in vitro pharmacodynamic models in which in vivo pharmacokinetics and bacterial growth conditions can be simulated. However, systematic comparisons between the two methods are lacking. We evaluated the bactericidal activities of ceftazidime, at two different concentration/MIC ratios (C/MICs), against 10 clinical isolates of Pseudomonas aeruginosa in a two-compartment model with continuous-infusion conditions and a 2-h half-life. These values were compared to those determined by traditional 24-h time-kill (TTK) methods at the same C/MICs. Bactericidal activities were compared by using area under the colony count-time curves. Antibiotic exposure (area under the drug concentration-time curve) was also evaluated. Although bactericidal activity appeared greater by the TTK method (P = 0.05), when it was normalized for drug exposure, these differences disappeared (P = 0.2). This disparity was likely due to differences in drug exposure in the TTK method and in the peripheral compartment of the model (site of bacteria) over the first 8 h of the experiment, during which the antibiotic accumulated to target concentrations. This suggests that the bactericidal effects with constant antibiotic concentrations are similar in the two methods; however, this may not hold true with fluctuating drug concentrations. Further, results from the pharmacodynamic model may theoretically be more relevant, as in vivo pharmacokinetics and bacterial growth conditions call be more faithfully simulated.