Clinical evaluation of vancomycin dosage regimens based on the Bayesian method

• Published in: Japanese Journal of Chemotherapy Vol. 46; no. 12; pp. 491 - 497
• Main Authors: Nagayama, Yoshiaki, Yamazaki, Akira, Takahashi, Satoru, Saito, Nobuhiko, Sako, Kenichi, Takao, Yoshihiro, Kobayashi, Teruaki, Shinozaki, Kimikazu
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Chemotherapy 1998; 公益社団法人 日本化学療法学会
• Subjects: MRSA; TDM; バンコマイシン; ベイジアン法; 投与設計
• ISSN: 1340-7007; 1884-5886
• DOI: 10.11250/chemotherapy1995.46.491

Vancomycin hydrochloride (VCM) has the highest antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The clinical usefulness of the dosage regimens based on a two compartment model and the Bayesian method were evaluated to establish a safe and effective VCM treatment for infections caused by MRSA. The subjects were 23 patients (24 courses) treated with VCM from September 1993 to September 1997. VCM (500-1, 000mg/dose) was administered by intravenous infusion over 1.0 to 1.5 hours and dosing intervals were from 12 to 48 hours. Serum VCM concentrations at the trough and 1 hour after the end of infusion (peak) were measured until 96 hours from the onset of therapy. Pharmacokinetic parameters were calculated for VCM dosage regimens based on a two compartment model and the Bayesian method by Rodvold's population pharmacokinetic parameters. The prediction of serum VCM concentrations and the dosage regimens were analyzed. The dosage and the predicted serum VCM concentration were calculated by the programs using two points of serum VCM concentrations. Although predicted values were slightly lower than measured values at the trough, the predictability of serum VCM concentrations was good. In the initial dosage setting, VCM doses of 9.09-27.03 (16.03±5.46, mean±SD) mg/kg/dose were administered and serum VCM concentrations at the trough and peak were achieved within a therapeutic range in 9 courses (37.5%) and 8 courses (33.3%), respectively. After the dosage regimens, VCM doses became 9.13-31.58 (21.28±6.49, mean±SD) mg/kg/dose and serum VCM concentrations achieved within a therapeutic range at the trough and peak were similar in 18 courses (75%), respectively. The rate of bacterial eradication (MRSA) was 60% (18/30). Although other antibiotics or β-lactam antibiotics were used in 17 courses concomitantly, the efficacy rate was 58.3%. No case developed into renal failure due to VCM treatment. These data indicate that the Bayesian method is useful for interpreting patient pharmacokinetics and conducting a safe and effective treatment with VCM.