Should furosemide (Lasix) injection be diluted for intravenous (IV) push in patients with impaired renal function or those at risk of hypotension?

Furosemide IV Push Administration

Furosemide injection does not require dilution for IV push administration, but must be given slowly over 1-2 minutes to prevent ototoxicity, regardless of the patient's renal function or hemodynamic status. 1

Standard Administration Protocol

The FDA-approved administration technique is straightforward:

• Administer undiluted furosemide slowly via IV push over 1-2 minutes for standard doses (20-80 mg) 1
• The slow injection rate is critical to minimize the risk of ototoxicity, not the dilution status 2, 1
• For doses administered intramuscularly or intravenously, the initial dose should be given slowly under close medical supervision 1

High-Dose Administration Requirements

When higher doses are necessary, the administration method changes significantly:

• For doses ≥250 mg, furosemide must be diluted and given as a controlled IV infusion rather than IV push 2
• Add furosemide to Normal Saline, Lactated Ringer's, or D5W after adjusting pH to >5.5 1
• Administer the diluted solution at a rate not exceeding 4 mg/min to prevent ototoxicity 2, 1
• Infusions should be administered over 5-30 minutes for high doses 2

Critical pH Considerations

• Furosemide injection has a pH of approximately 9 and may precipitate at pH values below 7 1
• Never mix furosemide with acidic solutions (labetalol, ciprofloxacin, amrinone, milrinone) as precipitation will occur 1
• Do not add furosemide to a running IV line containing acidic products 1

Special Population Considerations

Patients with Renal Impairment

• The same slow IV push technique (1-2 minutes) applies regardless of renal function 1
• Higher doses may be required in patients with creatinine clearance <30 mL/min to achieve therapeutic tubular concentrations, but the administration rate remains unchanged 3
• No dose adjustment in administration technique is needed; only the total dose may need adjustment 4

Patients at Risk of Hypotension

• Slow administration (1-2 minutes) is already the standard and provides adequate protection against acute hemodynamic changes 1
• Ensure systolic blood pressure ≥90-100 mmHg before administering furosemide 2, 3
• The slow injection rate allows for immediate cessation if hypotension develops 5

Common Pitfalls to Avoid

• Do not dilute standard doses (20-80 mg) for IV push—this adds unnecessary steps without clinical benefit 1
• Do not administer furosemide rapidly (faster than 1-2 minutes for standard doses)—this significantly increases ototoxicity risk 2, 5
• Do not assume dilution is required for renal impairment—the administration technique is the same, only total dose considerations differ 3, 4
• Do not mix with acidic medications—precipitation will render the drug ineffective 1

Monitoring During Administration

• Monitor blood pressure every 15-30 minutes in the first 2 hours after administration, especially with higher doses 2
• Assess for signs of ototoxicity (tinnitus, hearing changes) particularly with doses >80 mg or rapid administration 2, 5
• Place bladder catheter in acute settings to rapidly assess treatment response 2