About This Calculator

The Meropenem-Vaborbactam Dose Calculator is a clinical tool designed for healthcare professionals to determine the appropriate dosing regimen for adult patients based on their renal function. By calculating or accepting a direct value for creatinine clearance (CrCl), it provides tailored recommendations to optimize efficacy and minimize potential toxicity associated with impaired drug clearance.

Outputs

After processing the inputs, the calculator provides the following key information:

• Calculated Creatinine Clearance (CrCl): The patient’s estimated CrCl in mL/min, if the Cockcroft-Gault method is used.
• Renal Function Category: A classification of the patient’s kidney function (e.g., Normal Function, Mild Impairment, Severe Impairment).
• Recommended Dose: The specific dose of meropenem-vaborbactam in grams.
• Dosing Schedule: The recommended administration frequency (e.g., every 8 hours, every 12 hours).
• Infusion Time: The standard infusion duration for all doses, which is 3 hours.
• Special Instructions: Important notes, such as administration timing for patients on hemodialysis.

How to Use

The tool offers two methods for determining the appropriate dose:

1. Calculate Creatinine Clearance (Cockcroft-Gault)

This is the primary method and requires the following patient data:

• Age: In years (must be 18 or older).
• Weight: Patient’s actual body weight in kilograms (kg) or pounds (lbs).
• Serum Creatinine (SCr): In mg/dL or µmol/L.
• Sex: Male or female, as this is a factor in the formula.

2. Enter Known CrCl / eGFR

Use this option if you have a recently calculated creatinine clearance or estimated glomerular filtration rate (eGFR) value available. Simply enter the value in mL/min to receive the corresponding dosing recommendation.

Dosing Overview

Dosing recommendations for meropenem-vaborbactam are based on creatinine clearance (CrCl). All doses should be administered as a 3-hour intravenous (IV) infusion.

Switching

When switching from another antibiotic to meropenem-vaborbactam, or vice versa, clinical judgment is paramount. Consider the timing of the last dose of the previous drug, its half-life, and the patient’s current clinical and renal status. No specific washout period is generally required, but the dosing schedule should be initiated based on the patient’s renal function as determined by this calculator.

Missed Dose

If a dose of meropenem-vaborbactam is missed, it should be administered as soon as possible. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. The regular dosing schedule should then be resumed. Do not administer two doses at the same time to make up for a missed one.

Safety Alerts

Meropenem-vaborbactam, like other beta-lactam antibiotics, carries important safety considerations:

• Hypersensitivity Reactions: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported. Before initiating therapy, inquire about previous hypersensitivity reactions to carbapenems, penicillins, or other beta-lactam agents.
• Seizure Potential: Carbapenems may cause central nervous system (CNS) adverse effects, including seizures. This risk is highest in patients with pre-existing CNS disorders or compromised renal function.
• Clostridioides difficile-Associated Diarrhea (CDAD): CDAD has been reported with nearly all systemic antibacterial agents and may range in severity from mild diarrhea to fatal colitis.

Frequently Asked Questions (FAQ)

Why is actual body weight used for the Cockcroft-Gault calculation?

The original Cockcroft-Gault formula was developed and validated using actual body weight. The prescribing information for Vabomere® (meropenem-vaborbactam) specifies dosing based on CrCl estimated via this method, making actual body weight the standard input.

What should I do for a patient on hemodialysis (HD)?

For patients on HD, the recommended dose is 1 gram every 12 hours. On days when dialysis is performed, the dose should be administered after the dialysis session is complete to avoid premature removal of the drug from circulation.

Can I use an eGFR value from the lab instead of calculating CrCl?

Yes, you can use the “Enter Known CrCl / eGFR” option. While the prescribing information is based on Cockcroft-Gault CrCl, for most adult patients with stable creatinine, eGFR (from MDRD or CKD-EPI) provides a reasonable estimate for dose adjustment purposes. However, CrCl is preferred.

Is this calculator appropriate for pediatric patients?

No. This calculator is designed for adults (age 18 and older) only. The safety and effectiveness of meropenem-vaborbactam in pediatric patients have not been established.

What is the standard infusion time?

All doses of meropenem-vaborbactam, regardless of the patient’s renal function, must be infused intravenously over 3 hours.

Why does the dose change with renal function?

Both meropenem and vaborbactam are primarily cleared from the body by the kidneys. In patients with renal impairment, the drugs are not cleared as efficiently, leading to higher concentrations in the blood. The dose is reduced to prevent drug accumulation and potential dose-related side effects.

Is there a dose adjustment for hepatic impairment?

No dose adjustment is necessary for patients with hepatic impairment, as the drug is not significantly metabolized by the liver.

What is the purpose of vaborbactam?

Vaborbactam is a beta-lactamase inhibitor. It has no antibacterial activity on its own. Its purpose is to protect meropenem from degradation by certain beta-lactamase enzymes, including Klebsiella pneumoniae carbapenemase (KPC), thereby restoring meropenem’s activity against resistant bacteria.

References

1. VABOMERE® (meropenem and vaborbactam) for injection, for intravenous use. U.S. Food and Drug Administration. Revised: 06/2021.
2. Vabomere® Healthcare Professional Information. Merck & Co., Inc.
3. Papp-Wallace KM, et al. The Newest Beta-Lactamase Inhibitor, Vaborbactam: A Potent Inhibitor of KPC Carbapenemases. Antimicrob Agents Chemother. 2018;62(4):e02209-17. doi:10.1128/AAC.02209-17
4. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. doi:10.1159/000180580