What is the conversion from intravenous (IV) Bumex (bumetanide) to oral (PO) bumetanide?

From the Guidelines

Conversion from IV to Oral Bumetanide

The conversion from intravenous (IV) Bumex (bumetanide) to oral (PO) bumetanide is approximately 1:1, meaning that the dose of oral bumetanide is similar to the dose of IV bumetanide.

• Key points to consider when converting IV to oral bumetanide include:
  • The bioavailability of oral bumetanide is high, which supports a 1:1 conversion ratio 1.
  • The duration of action of oral bumetanide is 4-6 hours, which may require twice-daily dosing 1.
  • The maximum total daily dose of oral bumetanide is 10 mg, which should not be exceeded 1.
• It is essential to monitor patients closely when converting from IV to oral bumetanide, as individual responses to diuretic therapy can vary 1.
• Factors that can affect the response to diuretic therapy, such as dietary sodium intake, use of nonsteroidal anti-inflammatory drugs (NSAIDs), and renal function, should be taken into consideration when converting IV to oral bumetanide 1.

The FDA Drug Labels for bumetanide (PO) do not address this question.

From the Research

Conversion from IV to Oral Bumetanide

The conversion from intravenous (IV) Bumex (bumetanide) to oral (PO) bumetanide can be based on the drug's pharmacokinetic properties.

• Bumetanide is rapidly and almost completely absorbed after oral administration, with peak plasma levels achieved approximately 30 minutes after oral administration 2.
• The absolute bioavailability of oral bumetanide is approximately 80% 3, 4.
• The potency of bumetanide is about 40-fold higher than that of frusemide (furosemide) 5, 6.
• 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 5.

Dosing Considerations

• When converting from IV to oral bumetanide, the dose may need to be adjusted based on the patient's response and the severity of their condition.
• The usual oral dose of bumetanide is 0.5 to 2 mg/day, while the IV dose is typically 0.5 to 1 mg 5, 4.
• Higher doses of bumetanide may be required in patients with chronic renal failure or nephrotic syndrome, up to 15 mg/day 5.

Key Points

• Bumetanide has a rapid onset of action, with peak effects occurring within 30 minutes to 1 hour after administration 2, 5.
• The drug is rapidly eliminated from the body, with a half-life ranging from 24-86 minutes 3.
• Bumetanide is generally well-tolerated, but may cause side effects such as hypokalemia, hypochloremia, and metabolic alkalosis 2, 5, 6.