Can Furosemide (Lasix) contribute to orthostatic dizziness?

From the Guidelines

Yes, Lasix (furosemide) can cause dizziness when standing, a condition known as orthostatic hypotension, due to its potent diuretic effect leading to dehydration and reduced blood volume. This occurs because Lasix increases urine output, which can lead to dehydration and reduced blood volume 1. When you stand up, gravity pulls blood downward, and if your blood volume is already low due to the medication, your blood pressure may drop suddenly, causing dizziness, lightheadedness, or even fainting. Some key points to consider include:

• The severity of orthostatic hypotension is correlated with premature death, as well as increased numbers of falls and fractures 1.
• Diuretics, such as Lasix, may further aggravate orthostatic hypotension 1.
• To minimize this side effect, it's advisable to change positions slowly, especially when getting up from lying or sitting positions.
• Staying well-hydrated (unless fluid restriction is recommended by your doctor) and taking Lasix earlier in the day rather than at bedtime can also help reduce these symptoms.
• If dizziness becomes severe or persistent, you should consult your healthcare provider, as dosage adjustments may be necessary. In particular, elderly patients, those taking higher doses, or when the medication is first started are more prone to this effect 1.

From the FDA Drug Label

The postural hypotension that sometimes occurs can usually be managed by getting up slowly.

• Postural hypotension is a condition that can cause dizziness when standing.
• The FDA drug label for furosemide (Lasix) mentions that postural hypotension can occur and advises patients to get up slowly to manage it.
• This suggests that Lasix can attribute to dizziness when standing due to postural hypotension 2.

From the Research

Diuretics and Dizziness

• The provided studies do not directly address the question of whether Lasix (furosemide) can attribute to dizziness when standing 3, 4.
• However, it is known that diuretics like furosemide can cause fluid and electrolyte abnormalities, which may lead to dizziness and other symptoms 3.
• The studies focus on the comparative effects of furosemide and other diuretics in the treatment of heart failure 3, and the mechanisms of furosemide's effects on renal and cardiovascular physiology 4.
• While the studies do not specifically mention dizziness as a side effect of furosemide, they do discuss the potential for diuretics to cause dehydration and electrolyte imbalances, which can contribute to dizziness and lightheadedness 3, 4.

Potential Mechanisms

• The inhibition of the Na(+)-K(+)-2Cl(-) cotransporter (NKCC)-2 in the ascending limb of the loop of Henle by furosemide can lead to changes in renal blood flow and glomerular filtration rate, which may contribute to dizziness 4.
• The activation of tubuloglomerular feedback or renin release, particularly if renal function is already compromised, may also play a role in the development of dizziness 4.
• However, the exact mechanisms by which furosemide may cause dizziness are not well understood and require further study 4.