# Vancomycin Empiric Dosing Calculator (2020 ASHP/IDSA)

Empiric starting dosing for vancomycin per the 2020 ASHP/IDSA/PIDS/SIDP consensus guideline. Loading dose: 20–25 mg/kg actual body weight (obesity cap 3000 mg). Maintenance dose: 15–20 mg/kg actual body weight every 8–12 h. Optional creatinine clearance (CrCl) input suggests an empiric dosing interval (≥90 → q8h, 50–89 → q12h, 30–49 → q18–24h, 10–29 → q24h, <10 → q24–48h). Optional measured trough is classified against the SECONDARY trough target of 15–20 mg/L. The 2020 guideline shifted the primary monitoring target to AUC₀₋₂₄/MIC = 400–600 mg·h/L (within first 24–48 h); trough-only monitoring is no longer recommended as primary. Derived from Rybak MJ et al., Am J Health-Syst Pharm 2020. Empiric start doses ONLY — individualize by AUC-guided Bayesian monitoring. Not medical advice.

> Canonical page: https://elysiatools.com/en/tools/vancomycin-dosing

- **Category:** Health

- **Keywords:** vancomycin, empiric dosing, loading dose, maintenance dose, trough, AUC, MIC, MRSA, ASHP, IDSA, therapeutic drug monitoring, TDM, nephrotoxicity, antibiotic, pharmacokinetics

## Overview

This vancomycin empiric dosing calculator estimates a loading dose and maintenance dose from actual body weight, suggests an dosing interval from optional creatinine clearance (CrCl), and classifies an optional trough against the secondary 15–20 mg/L target. It follows the 2020 ASHP/IDSA consensus approach, which prioritizes AUC₀₋₂₄/MIC 400–600 mg·h/L for monitoring. It provides empiric starting doses only and is not medical advice.

## Inputs

- **Actual Body Weight (kg)** (number): Actual body weight in kg. Must be positive.
- **Creatinine Clearance CrCl (mL/min, optional)** (number): Optional CrCl in mL/min. Guides empiric dosing interval. Must be ≥0.
- **Target trough (mg/L, optional)** (number): Optional measured/target trough in mg/L for classification against the secondary trough target.
- **Decimal Places** (number)

## When to use

- Estimate an initial vancomycin loading dose from a patient’s actual body weight.
- Calculate the empiric maintenance dose range and use CrCl to suggest a dosing interval.
- Classify a measured trough while recognizing that AUC-guided monitoring is the primary target.

## How it works

- Enter the patient’s actual body weight in kilograms.
- Optionally enter CrCl to receive an empiric interval suggestion based on renal function.
- Optionally enter a measured or target trough to classify it against the secondary 15–20 mg/L range.
- Review the loading dose, maintenance dose, interval suggestion, and AUC monitoring target in the JSON result.

## Use cases

- Pharmacists can estimate empiric loading and maintenance dose ranges before individualized therapeutic drug monitoring.
- Clinicians can compare an optional trough result with the secondary 15–20 mg/L target.
- Students and healthcare teams can review how actual body weight and CrCl affect an initial vancomycin regimen.

## Frequently asked questions

### What weight does the calculator use?

It uses actual body weight in kilograms for both loading and maintenance dose estimates.

### How is the loading dose calculated?

The loading dose is 20–25 mg/kg of actual body weight, with a 3,000 mg cap for obesity.

### How is the maintenance dose calculated?

The maintenance dose is 15–20 mg/kg of actual body weight.

### What does the optional CrCl input do?

CrCl suggests an empiric interval: q8h for 90 or higher, q12h for 50–89, q18–24h for 30–49, q24h for 10–29, and q24–48h below 10 mL/min.

### Is a trough of 15–20 mg/L the primary monitoring target?

No. The primary target is AUC₀₋₂₄/MIC 400–600 mg·h/L; a 15–20 mg/L trough is classified as a secondary target.

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