Administration of tobramycin in the beginning of the hemodialysis session: a novel intradialytic dosing regimen.

BACKGROUND: Aminoglycoside antibiotic efficacy is related to peak concentration (C(max)) and postantibiotic effect, whereas toxicity is directly related to body exposure as measured by area under the serum concentration versus time curve (AUC). On the basis of pharmacokinetic simulation models, tobramycin administration during the first 30 min of high-flux hemodialysis achieves similar C(max) but significantly lower AUC and prehemodialysis concentrations compared with conventional dosing in the last 30 min of hemodialysis. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: To test this hypothesis, a pilot study in which five adult chronic hemodialysis patients who were undergoing high-flux dialysis received one dose of tobramycin 1.5 mg/kg intravenously during the first or last 30 min of hemodialysis was conducted. After a 1-mo washout period, patients crossed over to the other treatment schedule. Tobramycin serum concentrations were measured to determine C(max), interdialytic and intradialytic elimination rate constants and half-lives, AUC, and clearance. RESULTS: Tobramycin administration during the first and last 30 min of hemodialysis resulted in similar C(max) of 5.63 +/- 0.49 and 5.83 +/- 0.67 mg/L (P > 0.05) but significantly lower prehemodialysis concentrations of 0.16 +/- 0.09 and 2.44 +/- 0.43 mg/L (P < 0.001) and AUC of 21.06 and 179.23 +/- 25.84 mg/h per L (P < 0.001), respectively. CONCLUSIONS: Tobramycin administration during the first 30 min of hemodialysis results in similar C(max) but lower AUC to conventional dosing, which may translate into comparable efficacy but lower toxicity.

The use of wireless laptop computers for computer-assisted learning in pharmacokinetics.

OBJECTIVE: To implement computer-assisted learning workshops into pharmacokinetics courses in a doctor of pharmacy (PharmD) program. DESIGN: Workshops were designed for students to utilize computer software programs on laptop computers to build pharmacokinetic models to predict drug concentrations resulting from various dosage regimens. In addition, students were able to visualize through graphing programs how altering different parameters changed drug concentration-time curves. Surveys were conducted to measure students' attitudes toward computer technology before and after implementation. Finally, traditional examinations were used to evaluate student learning. ASSESSMENT: Doctor of pharmacy students responded favorably to the use of wireless laptop computers in problem-based pharmacokinetic workshops. Eighty-eight percent (n = 61/69) and 82% (n = 55/67) of PharmD students completed surveys before and after computer implementation, respectively. Prior to implementation, 95% of students agreed that computers would enhance learning in pharmacokinetics. After implementation, 98% of students strongly agreed (p < 0.05) that computers enhanced learning. Examination results were significantly higher after computer implementation (89% with computers vs. 84% without computers; p = 0.01). CONCLUSION: Implementation of wireless laptop computers in a pharmacokinetic course enabled students to construct their own pharmacokinetic models that could respond to changing parameters. Students had greater comprehension and were better able to interpret results and provide appropriate recommendations. Computer-assisted pharmacokinetic techniques can be powerful tools when making decisions about drug therapy.