Clinically digital program support for personalised dosing of vancomycin
European Statement
Clinical Pharmacy Services
Author(s)
Wei Wang, Hao Bai
Why was it done?
It depend on the pharmacokinetic (PK)/pharmacodynamic (PD) of vancomycin. Vancomycin can be described as a kinetic model with one compartment connected by a series of first-order kinetic rate processes. The mini programme uses two drug levels during the same dosing interval by the TDM to calculate the area under the curve (AUC) of vancomycin and integrated into patients’ condition and minimal inhibitory concentration of pathogen to provide an optimal dosing regimen of vancomycin.
What was done?
We designed and developed a mini programme support for personalised therapeutic drug monitoring (TDM) of vancomycin. This programme can be easily used in the WeChat by the mobile device.
How was it done?
The traditional vancomycin TDM strategy, which is guided by trough concentrations, has several limitations:
The recommended trough concentration range of 10-15mg/L assumes that the bacteria’s minimum inhibitory concentration (MIC) for vancomycin is ≤1mg/L. However, with the drifting of vancomycin’s MIC values over recent years, this trough concentration has not been able to effectively guide patient prognosis, as has been confirmed by many clinical studies.
There are practical difficulties: for example, the 2009 IDSA guidelines clearly specify that the trough concentration of vancomycin should be sampled half an hour before the fifth dose. However, in reality, due to misunderstandings by nursing staff or excessive workload, sampling times often deviate from this guideline.
After the trough concentration has been determined, there are no explicit measures for dose adjustment. The 2009 IDSA guidelines do not provide recommendations on how to adjust subsequent doses based on trough concentrations.
A decade later, in 2020, the IDSA released new vancomycin TDM guidelines. These guidelines suggest moving away from the trough concentration TDM strategy for vancomycin, and instead recommend using an AUC-guided strategy, determined by two-point blood concentration monitoring of vancomycin.
What has been achieved?
Vancomycin follows first-order pharmacokinetics. To monitor the AUC of vancomycin, it is necessary to measure the serum vancomycin concentration at two steady-state points, then use Monte Carlo simulations and Bayesian software to calculate the AUC and adjust the dosage. This process requires a large number of calculations. Therefore, there is an urgent need for an auxiliary decision making system in clinical practice that can facilitate personalised dosing of vancomycin.
What next?
This mini programme has run above 1 year, providing personalised medicine service of vancomycin to hundreds of patients in China, guiding the precise and rational use of antimicrobial drugs , enhancing the effectiveness of vancomycin and reducing drug toxicity in clinical practice.