What is the relationship between hypotension and Lasix (Furosemide)?

From the Guidelines

If a patient has soft blood pressure and is taking Lasix (furosemide), the medication should be used with caution and the healthcare provider should be contacted if systolic blood pressure is below 90 mmHg or if the patient is experiencing symptoms like dizziness, lightheadedness, or fainting. The use of diuretics like Lasix in patients with heart failure is recommended to improve symptoms, as stated in the 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 1. However, it is crucial to monitor symptoms, urine output, renal function, and electrolytes during the use of intravenous diuretics. Some key points to consider when using Lasix in patients with soft blood pressure include:

• The initial recommended dose of furosemide should be 20–40 mg intravenously (or equivalent) for patients with new-onset acute heart failure or those with chronic, decompensated heart failure not receiving oral diuretics 1.
• Diuretics should be given either as intermittent boluses or as a continuous infusion, and the dose and duration should be adjusted according to the patient's symptoms and clinical status 1.
• The healthcare provider may need to adjust the Lasix dosage or consider alternative medications based on the patient's condition and overall health status, as suggested in the 2009 focused update incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management of heart failure in adults 1.
• Patients should monitor their blood pressure regularly while on Lasix, stay well-hydrated unless instructed otherwise, and rise slowly from sitting or lying positions to avoid orthostatic hypotension.
• The ultimate goal of diuretic treatment is to eliminate clinical evidence of fluid retention, such as jugular venous pressure elevation and peripheral edema, while being cautious of potential hypotension and azotemia 1.

From the FDA Drug Label

The postural hypotension that sometimes occurs can usually be managed by getting up slowly. The FDA drug label does mention that hypotension can occur with the use of Furosemide, also known as Lazix, and that it can be managed by getting up slowly 2.

• Soft blood pressure is likely referring to hypotension or low blood pressure.
• Furosemide can cause hypotension due to its diuretic effects, which can lead to dehydration and blood volume reduction.
• Patients taking Furosemide should be advised to manage hypotension by getting up slowly and to report any symptoms of excessive fluid and/or electrolyte losses to their healthcare provider 2.

From the Research

Soft Blood Pressure and Lazix

• Soft blood pressure is not a commonly used term in medical literature, but it can be inferred to refer to a condition where blood pressure is not severely elevated, but still requires management.
• Lazix, also known as furosemide, is a loop diuretic used to treat fluid overload and edema in patients with heart failure, liver disease, and kidney disease 3.
• The use of furosemide in patients with soft blood pressure may be beneficial in reducing fluid overload and improving symptoms, but its effects on blood pressure are not well understood 4, 5.

Mechanism of Action

• Furosemide works by inhibiting the Na(+)-K(+)-2Cl(-) cotransporter (NKCC)-2 in the ascending limb of the loop of Henle, leading to increased urine production and reduction in extracellular fluid volume 3.
• The effects of furosemide on blood pressure are complex and may involve changes in venous compliance, renal blood flow, and glomerular filtration rate 3, 5.

Clinical Evidence

• Studies have shown that furosemide can be effective in reducing mortality and hospital readmissions in patients with acute decompensated heart failure, but its effects on blood pressure are not well established 4, 6.
• A systematic review and meta-analysis found that continuous infusion of furosemide was associated with a greater body weight reduction and potential increase in 24-h urine output compared to intermittent administration, but no difference in adverse events was noted 5.
• Another study found that exercise, including aerobic and resistance training, can be effective in reducing blood pressure and improving cardiovascular health, but its effects on patients with soft blood pressure and taking furosemide are not well understood 7.