From the Guidelines
When converting Bumex (bumetanide) from oral (PO) to intravenous (IV) administration, use a 1:1 conversion ratio, as supported by the most recent guidelines 1. This means that if a patient is taking 1 mg of oral bumetanide, they should receive 1 mg of IV bumetanide. The key points to consider in this conversion include:
- Bumetanide has equivalent bioavailability between oral and IV routes, with approximately 80-95% of the oral dose being absorbed.
- The onset of action differs between routes, with IV bumetanide acting within minutes while oral bumetanide takes effect in 30-60 minutes.
- The duration of action is about 4-6 hours regardless of administration route.
- When switching from IV to oral, maintain the same total daily dose but consider dividing it appropriately based on the patient's clinical status and fluid management needs.
- Monitor the patient's response closely after conversion, including urine output, electrolytes (particularly potassium), and renal function, as individual responses may vary despite the equivalent dosing. It's also important to note that the most recent guidelines from 2022 1 support the use of a 1:1 conversion ratio, and this approach is consistent with previous guidelines 1.
From the Research
Conversion from Oral to Intravenous Bumex
The conversion from oral (PO) to intravenous (IV) Bumex (bumetanide) can be determined based on the drug's bioavailability and potency.
- The bioavailability of bumetanide is approximately 80% after oral administration 2, 3.
- Bumetanide is about 40-fold more potent than frusemide (furosemide) 4.
- Studies have shown that oral or intravenous bumetanide 0.5 to 2 mg/day produces results comparable to those with frusemide 20 to 80 mg/day 4.
- The absolute bioavailability of the oral preparation is approximately 80% 3.
Dosing Considerations
When converting from oral to intravenous Bumex, the following considerations should be taken into account:
- The IV dose may be lower than the oral dose due to the higher bioavailability of the IV route 3.
- The potency of bumetanide should be considered when converting from oral to IV, as it is approximately 40-fold more potent than frusemide 4.
- The dose of bumetanide may need to be adjusted based on the individual patient's response and renal function 4, 5.