Bumex (Bumetanide) Dosing Guidelines
For adults with edema or heart failure, start bumetanide at 0.5–1.0 mg orally once daily in the morning, titrate by doubling the dose every 2–3 days until adequate diuresis is achieved (target weight loss 0.5–1.0 kg/day), with a usual maintenance range of 0.5–2.0 mg/day and a maximum of 10 mg/day; intravenous dosing mirrors oral dosing (0.5–1.0 mg initial bolus) because bioavailability is high (≥80%), and no dose adjustment is required for moderate renal impairment or elderly patients, though hepatic disease may prolong half-life and warrant closer monitoring. 1, 2, 3, 4
Oral Dosing
Starting Dose
- Begin with 0.5–1.0 mg once daily in the morning for most adults with edema or heart failure. 1, 2
- Patients with more severe volume overload or prior diuretic exposure may start at 1.0 mg once daily. 1, 3
Titration Increments
- If adequate diuresis is not achieved within 2–3 days, double the dose (e.g., 0.5 mg → 1.0 mg → 2.0 mg). 1, 2
- Continue doubling every 2–3 days until target weight loss of 0.5–1.0 kg/day is reached. 1, 2
Usual Maintenance Range
- Most patients respond to 0.5–2.0 mg/day. 1, 3, 4
- Patients with chronic renal failure or nephrotic syndrome may require up to 15 mg/day in divided doses. 3, 4
Maximum Daily Dose
- The maximum recommended dose is 10 mg/day. 1, 2
- Doses above 6 mg/kg/day increase ototoxicity risk and should be avoided. 2
Intravenous Dosing
Starting Dose
- Administer 0.5–1.0 mg IV bolus over 1–2 minutes. 1, 2
- For acute pulmonary edema or severe volume overload, start at 1.0 mg IV. 1, 3
Titration and Redosing
- If urine output remains inadequate after 2 hours, double the dose (e.g., 0.5 mg → 1.0 mg → 2.0 mg). 2
- Repeat dosing every 2–3 hours as needed until diuresis is achieved. 1, 2
Maximum IV Dose
- The maximum single IV dose is 10 mg. 1, 2
- Doses ≥250 mg should be infused over 4 hours to minimize ototoxicity. 2
IV-to-Oral Conversion
- Because bumetanide has ≥80% oral bioavailability, the IV and oral doses are equivalent (1:1 conversion). 3, 4, 5
- Transition to oral therapy once the patient is hemodynamically stable and volume overload is controlled. 2
Adjustments for Special Populations
Elderly Patients
- No dose adjustment is required based on age alone. 1, 2
- Start at the lower end of the dosing range (0.5 mg once daily) and titrate slowly, as elderly patients may have reduced renal clearance and prolonged half-life. 2, 5
- Monitor blood pressure, electrolytes, and renal function more frequently (every 3–7 days initially). 1, 2
Moderate Renal Impairment (CrCl 30–50 mL/min)
- No dose adjustment is required; bumetanide remains effective even in moderate renal dysfunction. 3, 4, 5
- Terminal half-life is prolonged in renal impairment, but total plasma clearance is preserved due to increased non-renal (hepatic) clearance. 5
- Higher doses (up to 10–15 mg/day) may be needed in advanced chronic kidney disease to overcome reduced tubular secretion. 3, 4
- Monitor serum creatinine, potassium, and sodium every 3–7 days during titration. 1, 2
Hepatic Disease
- No formal dose reduction is recommended, but bumetanide's half-life is significantly prolonged in cirrhosis due to reduced non-renal clearance. 5
- Start at 0.5 mg once daily and titrate cautiously, monitoring for signs of excessive diuresis or electrolyte disturbances. 5
- In cirrhotic patients with ascites, combine bumetanide with spironolactone (e.g., spironolactone 100 mg + bumetanide equivalent to furosemide 40 mg) to counteract secondary hyperaldosteronism. 2, 6
- Monitor liver function, electrolytes, and renal function every 3–7 days. 1, 2
Monitoring Parameters
Clinical Response
- Daily weights at the same time each day; target loss of 0.5–1.0 kg/day until dry weight is achieved. 1, 2
- Assess for resolution of peripheral edema, dyspnea, and jugular venous distension. 1, 2
Laboratory Monitoring
- Check serum potassium, sodium, and creatinine within 3–7 days of starting therapy or after any dose change. 1, 2
- Monitor for hypokalemia, hyponatremia, hyperuricemia, and metabolic alkalosis—common adverse effects of loop diuretics. 1, 3, 4
- Recheck electrolytes every 3–6 months during maintenance therapy. 1
Safety Thresholds
- Stop bumetanide immediately if:
Managing Diuretic Resistance
Sequential Nephron Blockade
- If bumetanide doses exceed 5 mg/day (equivalent to furosemide 200 mg/day) without adequate response, add a thiazide diuretic (e.g., hydrochlorothiazide 25 mg or metolazone 2.5–5 mg) rather than further escalating bumetanide. 2, 7
- Alternatively, add an aldosterone antagonist (spironolactone 25–50 mg) to enhance natriuresis and spare potassium. 1, 2
Conversion to IV Therapy
- If oral bumetanide fails, switch to IV bumetanide at twice the total daily oral dose (e.g., 2 mg oral → 4 mg IV total daily). 2
Spot Urine Sodium Check
- Measure spot urine sodium 2 hours after a dose; levels <50–70 mEq/L indicate inadequate diuretic effect and warrant dose escalation or combination therapy. 2
Common Pitfalls and Caveats
Avoid Underdosing
- Do not persist with 0.5 mg once daily in patients with significant volume overload; this dose is insufficient and delays euvolemia. 2, 3
- Titrate aggressively (doubling every 2–3 days) until target weight loss is achieved. 1, 2
Avoid Excessive Escalation
- Do not exceed 10 mg/day without adding a second diuretic class; bumetanide has a ceiling effect beyond which further dose increases offer no additional benefit. 1, 2
Electrolyte Replacement
- Hypokalemia occurs in ~3.6% of patients; supplement potassium and magnesium proactively, especially when combining with other diuretics. 2, 4
- Magnesium depletion impairs potassium repletion; correct magnesium deficits first. 2
Ototoxicity Risk
- Bumetanide has lower ototoxicity than furosemide but higher than torsemide. 2, 3
- Avoid doses >6 mg/kg/day and rapid IV boluses (>4 mg/min) to minimize hearing loss. 2
Drug Interactions
- NSAIDs and COX-2 inhibitors blunt diuretic efficacy; discontinue before escalating bumetanide. 1, 2
- Concurrent aminoglycosides dramatically increase ototoxicity risk; avoid co-administration. 2
Conversion from Furosemide
Equivalence Ratio
- 40 mg furosemide = 1 mg bumetanide. 2, 7
- Example: A patient on furosemide 80 mg/day converts to bumetanide 2 mg/day. 2, 7
Clinical Scenarios Favoring Bumetanide
- Patients with diuretic resistance to furosemide may respond better to bumetanide, particularly in renal disease. 3, 8
- Bumetanide is 40-fold more potent than furosemide (except for potassium excretion, where potency is lower). 3, 4