About This Calculator

The Bedaquiline Dose Calculator is a clinical support tool designed to help healthcare professionals determine the appropriate dosing regimen for bedaquiline (Sirturo®) in the treatment of multidrug-resistant tuberculosis (MDR-TB). It provides dosing information based on the specific treatment phase (induction or continuation) and highlights critical safety considerations, such as drug interactions and necessary baseline monitoring.

Understanding the Outputs

After inputting the required clinical data, the calculator provides a comprehensive dosing recommendation that includes:

• Recommended Dose: The specific milligram (mg) strength for the selected treatment phase.
• Dosing Schedule: The frequency of administration (e.g., daily or three times weekly).
• Administration Notes: Key instructions, such as the requirement to take bedaquiline with food.
• Clinical Warnings: Alerts for potential drug-drug interactions with CYP3A4 inducers/inhibitors and cautions for use in special populations (e.g., hepatic or renal impairment).
• Monitoring Requirements: A summary of essential monitoring, including the FDA Black Box Warning regarding QT prolongation and the need for regular ECG and liver function tests.

How to Use the Calculator

To ensure an accurate and safe dosing recommendation, follow these steps:

• Select Treatment Phase: Choose between the “Induction Phase (Weeks 1-2)” for initial daily dosing or the “Continuation Phase (Weeks 3-24)” for subsequent weekly dosing.
• Acknowledge Baseline Data: Confirm that you have reviewed the patient’s baseline ECG (for QTc interval) and liver function tests (LFTs). This is a mandatory safety check.
• Identify Drug Interactions: Specify if the patient is taking concomitant strong or moderate CYP3A4 inducers (e.g., rifampin) or inhibitors (e.g., ketoconazole), as these can significantly alter bedaquiline levels.
• Flag Special Populations: Indicate if the patient has pre-existing conditions such as severe hepatic or renal impairment, or if they are pregnant or breastfeeding, to receive appropriate warnings.
• Enter Patient Weight (Optional): While bedaquiline is not dosed by weight in adults, this information can be entered for context.

Standard Dosing Overview

The standard adult dosing for bedaquiline is divided into two distinct phases over a total of 24 weeks:

• Induction Phase (Weeks 1-2): 400 mg taken once daily with food.
• Continuation Phase (Weeks 3-24): 200 mg taken three times per week with food. There should be at least 48 hours between each dose (e.g., Monday, Wednesday, Friday).

Switching Therapy

Bedaquiline is a core component of specific MDR-TB regimens. Any decision to switch to or from bedaquiline outside of the standard 24-week treatment course should be made only under the guidance of a physician experienced in the treatment of MDR-TB. Do not stop or alter the dosing schedule without expert clinical consultation.

Managing a Missed Dose

Guidance for a missed dose depends on the treatment phase:

• During Induction (Weeks 1-2): The patient should take the missed dose as soon as they remember. They should then take the next dose at the usual scheduled time. The patient should not take two doses at the same time to make up for a missed one.
• During Continuation (Weeks 3-24): The patient should take the missed dose as soon as possible and then resume the three-times-a-week dosing schedule. Ensure at least 48 hours are maintained between doses.

Safety Alerts

Frequently Asked Questions

References

1. SIRTURO® (bedaquiline) Prescribing Information. Food and Drug Administration (FDA). accessdata.fda.gov
2. World Health Organization (WHO). (2022). WHO consolidated guidelines on tuberculosis. Module 4: Treatment – drug-resistant tuberculosis treatment. who.int
3. Centers for Disease Control and Prevention (CDC). Treatment for TB Disease. cdc.gov
4. European Medicines Agency (EMA). Sirturo (bedaquiline) Summary of Product Characteristics (SmPC). ema.europa.eu