Furosemide Dosage Calculation
You should administer 1 mL of furosemide IV to deliver the ordered 10 mg dose.
Calculation Method
The calculation is straightforward using the standard dosing formula:
- Available concentration: 10 mg/mL (as stated in the question, though note standard furosemide vials are typically 10 mg/mL per FDA labeling) 1
- Ordered dose: 10 mg
- Volume needed: 10 mg ÷ 10 mg/mL = 1 mL
Administration Guidelines
The IV dose must be given slowly over 1-2 minutes to avoid ototoxicity and other adverse effects 1, 2:
- Rapid IV administration can cause hearing loss, particularly at higher doses 2
- Slow administration over 1-2 minutes is the FDA-recommended standard for IV bolus furosemide 1
Clinical Context for This Dose
While 10 mg is below the typical starting dose, it may be appropriate in specific situations:
- Standard initial dosing for acute heart failure is 20-40 mg IV 3, 2
- Lower doses (10-20 mg) may be considered for patients who are diuretic-naive, have new-onset heart failure without prior renal dysfunction, or require cautious dosing 3
- Pediatric dosing is 1 mg/kg, which could result in a 10 mg dose for a 10 kg child 1
Critical Safety Checks Before Administration
Verify the patient does not have contraindications 3, 2:
- Systolic blood pressure must be ≥90 mmHg (ideally ≥100 mmHg) 3, 2
- Avoid if marked hypovolemia, severe hyponatremia, acidosis, or anuria is present 3
- In hypotensive patients, circulatory support must precede diuretic therapy 2
Monitoring After Administration
Essential monitoring includes 2:
- Urine output (bladder catheter placement recommended for accurate assessment) 3
- Blood pressure and signs of hypoperfusion 2
- Electrolytes, particularly potassium and sodium 3, 2
- Renal function 3, 2
Common Pitfall to Avoid
Do not confuse the concentration: Standard furosemide vials are 10 mg/mL (available as 20 mg/2 mL, 40 mg/4 mL, or 100 mg/10 mL) 1. Your question states "40ml" which appears to be an error—verify the actual vial concentration before drawing up the dose. If the vial is actually 40 mg/4 mL (10 mg/mL), then 1 mL is correct. If it's a different concentration, recalculate accordingly.