Can Lasix Be Given in This Patient?
Yes, furosemide (Lasix) can be safely administered to this patient with coronary artery disease, hypertension, and tachycardia, particularly if there is evidence of volume overload, pulmonary congestion, or heart failure. 1
Clinical Context for Furosemide Use
The appropriateness of furosemide depends critically on the clinical presentation:
When Furosemide Is Indicated
Acute severe hypertension with "flash" pulmonary edema: Initial therapy with intravenous nitroglycerin, furosemide, and a short-acting or intravenous ACE inhibitor is appropriate in patients presenting with acute coronary syndrome and pulmonary congestion 1
Evidence of volume overload: In the acute setting with CAD and hypertension, diuretics are primarily used for patients with evidence of increased filling pressures, pulmonary venous congestion, or heart failure 1
Heart failure with preserved or reduced ejection fraction: Loop diuretics such as furosemide are preferred over thiazides because they produce greater diuresis, work even in the presence of renal impairment, and have linear dose-response characteristics allowing escalation to high doses 1
Dosing Considerations
Standard dosing: Furosemide 20-40 mg produces significant diuretic and natriuretic effects in most patients with cardiac conditions 2
Higher doses when needed: High-dose furosemide (≥500 mg/day) can be used safely in severe cardiac failure refractory to lower doses, with careful monitoring 3
Route selection: Whether administered intravenously or orally depends on hemodynamic stability—IV route is preferred in acute, unstable presentations 1
Critical Monitoring Requirements
Electrolyte surveillance is mandatory when using furosemide in this population:
Serum electrolytes (particularly potassium), CO2, creatinine, and BUN should be determined frequently during the first few months of therapy and periodically thereafter 4
Hypokalemia may develop, especially with brisk diuresis, inadequate oral electrolyte intake, or when combined with other medications 4
In patients with CAD, digitalis therapy may exaggerate metabolic effects of hypokalemia, especially myocardial effects 4
Combination Therapy Approach
Furosemide should be combined with neurohormonal blockade rather than used as monotherapy:
The combination of diuretic therapy with an ACE inhibitor or ARB, a β-blocker, and/or an aldosterone antagonist provides effective therapy and avoids adverse activation of the RAAS and sympathetic nervous system 1
Among furosemide recipients who also received potassium supplements or potassium-sparing diuretics, hypokalemia was less frequent, less severe, and of slower onset 5
Safety Profile
Furosemide has a favorable safety profile in cardiovascular patients when used appropriately:
In a surveillance study of 2,367 hospitalized patients receiving furosemide (78% for congestive heart failure), adverse reactions occurred in 10.1%, but only 14 instances were considered life-threatening 5
The most common adverse reactions were intravascular volume depletion (4.6%), hypokalemia (3.6%), and other electrolyte disturbances (1.5%) 5
The frequency of adverse reactions increased progressively with higher daily doses but was not correlated with total cumulative dose 5
Important Caveats
Avoid excessive diuresis, which may cause dehydration and blood volume reduction with circulatory collapse and possibly vascular thrombosis, particularly in elderly patients 4
Tachycardia management: If tachycardia or ischemia is the predominant presentation without volume overload, intravenous esmolol together with intravenous nitroglycerin is usually the first choice rather than furosemide 1
Drug interactions: Furosemide combined with ACE inhibitors or ARBs may lead to severe hypotension and deterioration in renal function; an interruption or reduction in dosage may be necessary 4
Thiazides vs. loop diuretics: While thiazide diuretics play a major role in long-term BP control, in the acute setting with CAD, loop diuretics are preferred when volume overload is present 1