What are furosemide (Lasix) side effects?

Common side effects of furosemide are listed below. Tell your doctor if these side effects are severe or do not go away after a few days.

• Frequent urination
• Blurred vision
• Dizziness
• Low blood pressure and lightheadedness when going from sitting to standing
• Headache
• Diarrhea
• Constipation

Rarely, furosemide can cause more serious side effects. Call your doctor immediately if you experience:

• Fever
• Trouble breathing or swallowing
• Rash, hives, blisters, peeling, itching, or other signs of an allergic reaction
• Ringing in the ears, loss of hearing
• Yellowing of the skin or eyes

The above list may not include all the potential adverse effects of furosemide. Tell your healthcare professional right away if you have any unusual or allergic reaction or if the side effects are worsening. You can also report unusual adverse effects of furosemide to the Food and Drug Administration at 1-800-FDA-1088.

Furosemide overdose: In case of an intentional or accidental overdose of furosemide, contact your health care professional right away. You can also call your local poison control center or the national poison helpline at 1-800-222-1222. Signs and symptoms of an overdose of furosemide may include dizziness, confusion, extreme thirst, dry mouth, tiredness, stomach cramps, and vomiting.

Source: FDA