About Eravacycline Dosing

The Eravacycline Dose Calculator provides a recommended intravenous (IV) dosage regimen for adult patients with complicated intra-abdominal infections (cIAI). It bases its calculation on patient weight, hepatic function (Child-Pugh classification), and co-administration of strong CYP3A inducers, aligning with official prescribing information.

Calculator Outputs Explained

The tool generates a patient-specific dosing recommendation, which includes:

• Calculated Dose: The precise dose in milligrams (mg) based on the patient’s body weight.
• Dosing Frequency: The recommended interval for administration (e.g., every 12 or 24 hours).
• Administration Notes: Standard instructions for IV infusion, such as the required duration.
• Regimen Basis: A summary of the factors influencing the dose (e.g., “Standard Dose,” “Child-Pugh C,” or “CYP3A Inducer”).

How to Use

To determine the appropriate dose, follow these steps:

1. Enter Patient Weight: Input the patient’s weight and select the unit (kg or lbs).
2. Specify Hepatic Function: Choose the patient’s liver function status. Select “Severe (Child-Pugh C)” only for patients with this specific classification. Otherwise, use the default “Normal / Mild (A) / Moderate (B)”.
3. Indicate CYP3A Inducer Use: Specify whether the patient is concurrently taking a strong CYP3A inducer (e.g., rifampin, phenytoin, St. John’s Wort).

Dosing Overview

The recommended dosage of eravacycline (XERAVA™) is adjusted based on specific clinical factors:

• Standard Dosing: For most patients, the dose is 1 mg/kg administered intravenously every 12 hours.
• Severe Hepatic Impairment (Child-Pugh C): The dosing frequency is reduced to 1 mg/kg every 24 hours to account for decreased drug clearance.
• Concomitant Strong CYP3A Inducers: The dose is increased to 1.5 mg/kg every 12 hours to compensate for accelerated drug metabolism.
• Warning Scenario: The use of eravacycline in patients with both severe hepatic impairment (Child-Pugh C) and concurrent use of a strong CYP3A inducer has not been clinically studied. This situation requires careful consideration and consultation with a clinical pharmacist.

Switching

When switching a patient to eravacycline from another antibacterial agent, consider the half-life and mechanism of the previous drug. No specific washout period is defined, but the decision should be based on clinical judgment. Similarly, when transitioning from eravacycline to an oral agent, select an appropriate antibiotic based on susceptibility testing and the patient’s clinical status.

Missed Dose

If a dose of eravacycline is missed, it should be administered as soon as possible. If it is nearly time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule should be resumed. Do not administer two doses at once to make up for a missed dose.

Safety Alerts

• Eravacycline is a tetracycline-class antibacterial drug and shares warnings associated with this class. These may include tooth discoloration in children, photosensitivity, and potential for Clostridioides difficile-associated diarrhea.
• This tool is not a substitute for clinical judgment. The healthcare professional is responsible for verifying all calculations and consulting the full prescribing information before administration.
• The calculator is intended for use in adults with cIAI only. Safety and efficacy have not been established in pediatric patients.

Frequently Asked Questions

What is the standard dose of eravacycline for cIAI?
The standard dose is 1 mg per kilogram of body weight, administered via IV infusion every 12 hours.

How is the dose adjusted for patients with liver disease?
For patients with severe hepatic impairment (Child-Pugh C), the frequency is reduced to 1 mg/kg every 24 hours. No adjustment is needed for mild or moderate impairment.

My patient is taking rifampin. How does this affect the dose?
Rifampin is a strong CYP3A inducer. The eravacycline dose must be increased to 1.5 mg/kg every 12 hours to maintain efficacy.

Is a dose adjustment required for patients with kidney problems?
No, according to the prescribing information, no dosage adjustment is necessary for patients with any degree of renal impairment, including those on hemodialysis.

What is the valid weight range for this calculator?
The calculator is designed for patient weights between 30 kg (approx. 66 lbs) and 300 kg (approx. 660 lbs).

Can I use this calculator for indications other than cIAI?
This tool is specifically validated against the dosing recommendations for complicated intra-abdominal infections in adults.

Why does the tool show a warning for a patient with Child-Pugh C on a CYP3A inducer?
This combination has not been studied in clinical trials. The interaction between reduced clearance (from liver disease) and increased metabolism (from the inducer) is unpredictable, requiring expert clinical and pharmacological consultation.

How quickly should the IV infusion be administered?
Eravacycline should be infused intravenously over approximately 60 minutes.

References

• XERAVA™ (eravacycline) for injection, for intravenous use. U.S. Prescribing Information. FDA.
• Drugs@FDA: FDA-Approved Drugs. XERAVA (eravacycline). U.S. Food and Drug Administration.
• XERAVA™ (eravacycline) Official Website. Innoviva Specialty Therapeutics.
• Mazuski JE, Tessier JM, May AK, et al. The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection. Surg Infect (Larchmt). 2017;18(1):1-76.