When should furosemide (loop diuretic) not be used to control hypertension?

When Not to Give Furosemide in Controlling Hypertension

Furosemide should not be used for hypertension control in patients with severe hyponatremia, hypovolemia, hypotension, severe hypokalemia, hepatic encephalopathy, or progressive renal failure, as these conditions can be worsened by loop diuretic therapy and increase mortality risk. 1, 2

Absolute Contraindications

• Severe hyponatremia (serum sodium <120 mmol/L) - Furosemide can worsen electrolyte imbalances and should be discontinued immediately 1
• Hypovolemia or hypotension (SBP <90 mmHg) - Patients are unlikely to respond to diuretic treatment and may experience further hemodynamic compromise 1
• Severe hypokalemia (<3 mmol/L) - Furosemide should be stopped to prevent life-threatening arrhythmias 1
• Hepatic coma or overt hepatic encephalopathy - Diuretics can precipitate or worsen encephalopathy in cirrhotic patients 1, 2
• Progressive renal failure with increasing azotemia and oliguria - Furosemide should be discontinued as it may worsen renal function 2
• Anuria - Furosemide must be stopped in anuric patients as it will be ineffective and potentially harmful 1

Relative Contraindications and Cautions

• Renal impairment - Requires careful monitoring and dose adjustment; high doses may be ineffective and increase toxicity risk 1, 3
• Electrolyte disturbances - Correct potassium abnormalities before initiating therapy 1
• Hepatic cirrhosis with ascites - Therapy should be initiated in hospital settings due to risk of precipitating hepatic coma 2
• Concomitant use with nephrotoxic drugs - Particularly aminoglycosides, cisplatin, and NSAIDs which can enhance nephrotoxicity 2
• Patients receiving ACE inhibitors or ARBs - Combined use may lead to severe hypotension and deterioration in renal function 2

Specific Clinical Scenarios to Avoid Furosemide

In Liver Disease

• Patients with hepatic coma - Therapy should not be initiated until the underlying condition improves 2
• States of electrolyte depletion - Correct electrolyte abnormalities before starting furosemide 2
• Patients with marked hypovolemia - In cirrhosis, diuretics should only be used with intravascular fluid overload (evidenced by good peripheral perfusion and high blood pressure) 1

In Heart Failure

• Patients with symptomatic hypotension (SBP <90 mmHg) - Vasodilators are preferred over diuretics in these patients 1
• Severe obstructive valvular disease - Risk of hemodynamic compromise is increased 1

In Renal Disease

• Advanced CKD patients with hypertension - Consider thiazide diuretics which may be more effective than furosemide in some patients with severe renal failure 4
• Patients with marked hyponatremia - Correct sodium abnormalities before initiating therapy 1

Monitoring Requirements When Using Furosemide

• Serum electrolytes (particularly potassium, sodium) - Monitor frequently during the first few months of therapy 2
• Renal function (BUN, creatinine) - Regular monitoring is essential, especially in high-risk patients 2
• Blood pressure - Monitor for hypotension, especially when combined with other antihypertensive medications 1
• Urine output - Assess response to therapy and avoid excessive diuresis 1

Alternative Approaches for Hypertension Control

• Consider torsemide - May be preferable in patients with variable or unpredictable response to furosemide due to better oral bioavailability and longer duration of action 5
• Thiazide diuretics - May be more effective than loop diuretics in some patients with chronic kidney disease and hypertension 3, 4
• Aldosterone antagonists - Consider as first-line diuretic therapy in patients with cirrhosis and ascites 1
• Vasodilators - May be preferable in patients with SBP >110 mmHg who cannot tolerate diuretics 1

Remember that furosemide, while approved for hypertension treatment, is not typically a first-line agent for uncomplicated hypertension and should be reserved for patients with concomitant edematous conditions or those who have not responded adequately to thiazide diuretics 2, 6.