DISCUSSION
Antibiotic concentration in pancreas tissue is very important for the treatment of SAP patients with infections. Previous studies show that quinolones and carbapenems have high pancreatic tissue levels and aminoglycosides fail to penetrate into the pancreas in sufficient tissue concentrations[22-25]. However, there are limited data with respect to vancomycin. This case indicated the good penetration ability of vancomycin in human pancreatic tissue, which provides evidence for the prescription of vancomycin in SAP patients.
This result was inconsistent with another published animal study[29], which concluded only 9% of vancomycin can penetrate into pancreas tissue. The reason may be the difference between human and animal studies or the difference of concentration between drainage and tissue. Besides, it can also be explained as the increased permeability to pancreas tissue of vancomycin under the pathological inflammation state[30].
As for the dosage regimen, only renal function was considered for this patient. Twice measured trough steady state concentration was 11.9 mg·L-1 and 15.7 mg·L-1 respectively, which were within the therapeutic window of 10-20 mg·L-1[19]. AUC0-24h was three times of 154, which was also during the range of 400-600 recommended as the pharmacokinetics/pharmacodynamics target of vancomycin[20]. And the patient’s outcome was good. As a consequence, the dosage regimen for this patient was acceptable.
A previous study of the pharmacokinetics of vancomycin in patients with SAP[31] shows the trough concentration is relatively low, and the clearance is relatively high. However, the clearance (Table 1) of this patient is similar to the description of vancomycin pharmacokinetics characteristic in package insert[32]. But the pharmacokinetic parameters need to be validated with more future studies since we only have one patient.