Furosemide, widely known by the brand name Lasix, is a powerful loop diuretic used to remove excess fluid from the body. It is commonly prescribed when fluid retention starts affecting vital organs such as the heart, lungs, or kidneys.
This article is written as a complete patient-focused medical guide. It explains not only how furosemide works, but also who can take it, who should avoid it, available strengths, brand names, side effects, diet advice, required tests, and supportive medicines.
What Is Furosemide and Why Is It Prescribed?
Furosemide increases urine production by acting on the kidneys. Doctors prescribe it when the body retains excess salt and water, leading to swelling and breathing difficulty.
It is commonly used in:
- Patients with heart failure and leg or lung swelling
- Severe generalized swelling such as anasarca
- Kidney disease with fluid retention
- Liver cirrhosis with ascites
Important: Furosemide controls fluid overload but does not cure the underlying disease.
How Furosemide Works in the Body
Inside the kidneys, furosemide blocks salt reabsorption in a specific area called the loop of Henle. When salt is lost, water follows, resulting in increased urine output.
This rapid fluid loss reduces pressure on the heart and lungs but may disturb body electrolytes, especially potassium. A common complication is hypokalemia (low potassium).
Available Strengths (Dosage Forms in the Market)
Furosemide is available in the following strengths:
- Tablets: 20 mg, 40 mg
- Injection: 10 mg/ml (hospital use)
Note: The correct dose depends on age, kidney function, and disease severity. Never adjust the dose without medical advice.
Common Brand Names Available
Furosemide is sold under various brand names. Availability may vary by region.
- Lasix
- Frusix
- Frudex
- Furosemide (generic)
Always check the generic name “Furosemide” on the medicine strip.
Who Can Take Furosemide?
Doctors may prescribe furosemide for:
- Patients with heart-related fluid overload
- Kidney disease patients with swelling
- Liver disease patients with ascites
- Hospitalized patients requiring rapid fluid removal
Who Should NOT Take Furosemide?
Furosemide should be avoided or used with extreme caution in:
- Severe dehydration
- Very low blood pressure
- Patients unable to pass urine (anuria)
- Severe electrolyte imbalance
- Known allergy to sulfonamide medicines
Pregnant or breastfeeding women should use it only if clearly advised by a doctor.
Side Effects of Furosemide
Common Side Effects
- Frequent urination
- Dizziness or weakness
- Muscle cramps
- Dry mouth or thirst
Serious Side Effects (Seek Medical Help)
- Irregular heartbeat
- Severe weakness or confusion
- Sudden hearing problems (rare)
- Reduced urine output
Recommended Foods While Taking Furosemide
- Fresh fruits and vegetables
- Balanced diet with adequate protein
- Potassium-rich foods (only if advised by doctor)
- Adequate fluid intake (not excessive)
Foods and Drinks to Avoid
- High-salt packaged foods
- Alcohol
- Excess caffeine
- Very salty snacks
Important Pathology Tests for Monitoring
- Serum electrolytes (Sodium, Potassium)
- Kidney function tests (Creatinine, Urea)
- Blood pressure monitoring
- Body weight tracking
Supportive Medicines (Doctor Prescribed)
- Potassium supplements (if deficiency develops)
- Magnesium supplements
- Blood pressure control medicines
Trusted External Medical References
Frequently Asked Questions (FAQs)
Medical Disclaimer
This content is for educational purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider before starting or stopping any medication.
Source: Mahfooz Medical Health