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K A Rodvold

Publications and source records attributed to K A Rodvold.

78 records · Page 5Linked to original sources

Predictive performance of Sawchuk-Zaske and Bayesian dosing methods for tobramycin.

We evaluated the reliability of pharmacokinetic parameter estimations determined by the Sawchuk-Zaske method and by a Bayesian method for predicting steady-state tobramycin concentrations on day 4 and day 10 of therapy in 30 patients treated for gram-negative infections. We also assessed the effect of using only trough tobramycin concentrations on the predictive performance of the Bayesian method. The mean estimation of tobramycin volume of distribution was significantly different for the Bayesian methods compared with the Sawchuk-Zaske methods when the same number of L/kg). Comparing the Bayesian and Sawchuk-Zaske methods when the same number of serum concentrations was available, the Bayesian method overpredicted peak concentrations on day 4 of therapy. When only trough concentration data were used, the Bayesian method significantly overpredicted peak concentrations compared with the Sawchuk-Zaske method on days 4 and 10 of therapy. Each method predicted steady-state trough concentrations without significant differences in bias or accuracy. The Bayesian method may be useful in providing aminoglycoside dosing recommendations.

Aged↗

The influence of serum albumin and alpha 1-acid glycoprotein on vancomycin protein binding in patients with burn injuries.

Ten patients with burn injuries (mean total body surface area burn = 29% +/- 16) were studied at various points in the course of their burn therapy. Alpha 1-Acid glycoprotein, albumin, and vancomycin concentrations were determined with either a trough or peak vancomycin quantitative determination. Alpha 1-Acid glycoprotein concentrations ranged from 125 to 333 mg/dl and albumin concentrations ranged from 1.7 to 4.2 gm/dl. Vancomycin protein binding, as determined by ultrafiltration, averaged 29% +/- 6%. There was a strong (r = 0.92) relationship between percent protein-bound vancomycin and albumin. There was a poor statistical relationship between percent protein-bound vancomycin and alpha 1-acid glycoprotein (r = 0.28). Alpha 1-Acid glycoprotein appeared to have virtually no effect on the protein-binding characteristics of vancomycin over the range of concentrations studied.

Adult↗

National survey of once-daily dosing of aminoglycoside antibiotics.

To evaluate the scope of once-daily dosing of intravenous aminoglycoside antibiotics, a questionnaire was designed and mailed to a random sample of pharmacy directors at 500 acute care hospitals in the United States. The response rate was 68.4%. Nineteen percent of the respondents reported use of once-daily dosing of aminoglycosides. Affiliation with a pharmacy residency program and the presence of a pharmacokinetic consultation service by the pharmacy department were associated with this practice (p < 0.05). No other statistically significant differences were found. Reported indications, contraindications, and dosing were consistent with those found in the literature. The profession of pharmacy, as demonstrated by pharmacy residency programs and pharmacokinetic consultation services, appears to have been instrumental in implementing this method of dosing aminoglycosides.

Aminoglycosides↗

Retrospective evaluation of therapies for Staphylococcus aureus endocarditis.

We retrospectively evaluated antiinfective therapy for methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) endocarditis in 54 patients who had 57 treatment courses for the disease. Three treatments were assessed: 27 nafcillin-treated courses of MSSA endocarditis, 18 vancomycin-treated courses of MSSA endocarditis, and 11 vancomycin-treated courses of MRSA endocarditis. At baseline, patients with MSSA treated with vancomycin had more chronic conditions (p<0.01), a lower frequency of intravenous drug use (p<0.01), a lower hematocrit concentration (p<0.05), and a higher serum creatinine concentration (p<0.05) than the nafcillin group. Vancomycin-treated patients had a higher complication rate during therapy (p<0.05) and a longer duration in an intensive care unit (p<0.01) than the nafcillin group. The trend was for a higher complete response rate in the nafcillin group (74% vs 50%, p=0.12), but no difference in mortality (22% vs 28%, p=0.73). Patients with MRSA infection treated with vancomycin had higher mortality than those with MSSA who received that drug (55% vs 28%, p=0.24). Patients with vancomycin-treated MSSA endocarditis may have a poorer outcome than those who receive nafcillin, but this may be influenced by different or more severe clinical features.

Adult↗

Pharmacoeconomic analysis of ampicillin-sulbactam versus cefoxitin in the treatment of intraabdominal infections.

We conducted a retrospective pharmacoeconomic analysis of a prospective, multicenter, double-blind, randomized, controlled trial comparing the beta-lactamase inhibitor combination ampicillin-sulbactam (96 patients) and the cephalosporin cefoxitin (101) in the treatment of intraabdominal infections. An institutional perspective was adopted for the analysis. The primary outcomes of interest were cure and failure rates, development of new infection, and antibiotic-related adverse events. Epidemiologic data pertaining to outcomes was retrieved primarily from the trial, although results of other published studies were taken into consideration through extensive sensitivity analyses. Data pertaining to potential resource use and economic impact were retrieved mainly from the University Health Consortium and hospital-specific sources. When considering only costs associated with drug acquisition through cost-minimization analysis, a potential savings of $37.24/patient may be realized with ampicillin-sulbactam relative to cefoxitin based on an average 7-day regimen. Outcome data collected for the entire hospitalization during the trial revealed an approximately 9% greater frequency of failure with cefoxitin relative to ampicillin-sulbactam. When considering all outcomes of interest in the initial base-case analysis, a potential cost savings of approximately $890/patient may be realized with ampicillin-sulbactam relative to cefoxitin. In assessing the impact of the significant variability in probability and cost estimates, Monte Carlo analysis revealed a savings of $425/patient for ampicillin-sulbactam over cefoxitin (95% CI -$618 to $1516 [corrected]). Given the model assumptions, our analysis suggests a 78% certainty level that savings will be experienced when ampicillin-sulbactam is chosen over cefoxitin.

Abdominal Abscess↗