What Furosemide Treats
| Condition | Typical Dose |
|---|---|
| Heart failure (mild) | 20–40 mg once daily |
| Heart failure (severe) | 80–250 mg daily, may need IV |
| Kidney disease oedema | 40–80 mg twice daily |
| Hypertension (refractory) | 40–80 mg daily |
| Acute pulmonary oedema | 40–80 mg IV — emergency use |
Electrolytes to Monitor
| Electrolyte | Effect | Target / Action |
|---|---|---|
| Potassium | Furosemide causes potassium LOSS | Keep >3.5 mmol/L — supplement if low |
| Sodium | Can fall (hyponatraemia) with high doses | Keep >135 mmol/L |
| Magnesium | Can fall with furosemide | Keep >0.7 mmol/L |
| Creatinine / eGFR | Rises if over-diuresis (dehydration) | A rise >20% needs dose review |
Dehydration WarningSigns of too much furosemide: thirst, dizziness on standing, dry mouth, muscle cramps, dark urine. Contact your heart failure nurse or doctor if your weight drops more than 2 kg in 2 days.
Flexible DosingMany heart failure patients are taught to adjust their furosemide dose based on daily weight. Increase by 20–40 mg if weight rises >2 kg; reduce if signs of dehydration. Only do this if your doctor has specifically taught you this approach.
Why must I take furosemide in the morning?
Furosemide causes a strong surge in urine production within 1–2 hours of taking it. Taking it in the morning means this surge occurs during the day. Taking it in the evening causes repeated night-time toilet trips and disturbed sleep.
Will I need to take furosemide forever?
In chronic heart failure, yes — furosemide helps keep fluid from accumulating in the lungs and legs. Stopping it usually leads to rapid fluid reaccumulation. Never stop without consulting your doctor.
I'm on furosemide but my ankles are still swollen — why?
The ankles may not fully resolve, especially if you have venous insufficiency (valve problems in leg veins). Compression stockings and leg elevation help. Adding spironolactone or changing timing may help more.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.