Furosemide 40 mg: uses, price & cheaper substitutes
Prescription required (Schedule H)
Common uses: Fluid build-up (oedema) – swelling of the legs, body or lungs due to heart failure; Swelling due to kidney disease or nephrotic syndrome.
Listed MRPs range from ₹0.31 to ₹0.97 per tablet across 4 listings. Use only on a doctor's prescription.
Price comparison
| Brand | Manufacturer | Pack | MRP | ₹ / tablet | As on |
|---|---|---|---|---|---|
| Lasipen 40 | Morepen Laboratories Ltd | 10 | ₹3.09 | ₹0.31 | 19 October 2026 |
| Frusamide 40 | Sanofi India Ltd | 15 | ₹5.58 | ₹0.37 | 19 October 2026 |
| Frusenex 40 | Geno Pharmaceuticals Ltd | 10 | ₹4.89 | ₹0.49 | 19 October 2026 |
| Lasix 40 | Sanofi India Ltd | 15 | ₹14.51 | ₹0.97 | 19 October 2026 |
MRPs as printed/listed on the date shown; actual price may vary.
Uses
- Fluid build-up (oedema) – swelling of the legs, body or lungs due to heart failure.
- Swelling due to kidney disease or nephrotic syndrome.
- Fluid in the abdomen (ascites) and legs due to liver cirrhosis.
- High blood pressure that has not responded to other medicines, usually in kidney disease.
How to take it
Take the tablet in the morning with water, with or without food. If your doctor prescribes two doses, take the second by late afternoon so you are not up all night passing urine. It starts working within an hour and keeps you passing urine for around 6 hours, so plan outings accordingly. Weigh yourself regularly if your doctor asks, and drink the amount of fluid your doctor advises – not too much, not too little. Long-term use needs regular blood tests for potassium and kidney function.
Side effects
Common
- Passing a lot of urine for a few hours.
- Thirst and dry mouth.
- Dizziness or light-headedness on standing.
- Headache.
- Muscle cramps or twitching.
Serious
Stop and get medical help urgently if you notice any of these.
- Severe dehydration – very little dark urine, confusion, fainting.
- Low potassium or sodium – weakness, irregular heartbeat, severe cramps.
- Kidney problems – pain in the back or side, very little urine.
- Ringing in the ears or hearing loss, mainly with high doses or injections.
- Severe skin reaction with blisters and fever.
Safety information
Alcohol
Avoid alcohol. It adds to dehydration and the drop in blood pressure, causing faintness.
Pregnancy
Not usually used in pregnancy or breastfeeding unless the condition is serious. Tell your doctor if you are pregnant.
Kidney problems
Often prescribed in kidney disease, sometimes in higher doses, but kidney function and salts must be monitored. It can worsen kidney function if you become dehydrated.
Liver problems
Used for cirrhosis fluid, usually with spironolactone. Potassium changes can trigger confusion in liver disease, so blood tests are essential.
Children
Used in children for heart and kidney conditions with weight-based doses under a paediatrician.
Missed dose
Take it as soon as you remember, but not late in the evening. If it is nearly time for the next dose, skip it. Do not double up.
Interactions
- Ramipril, telmisartan, amlodipine and other blood pressure medicines – blood pressure can fall too much; doctors often start low.
- Digoxin, amiodarone, sotalol – low potassium makes heart rhythm problems more likely.
- Painkillers like ibuprofen, diclofenac – blunt its effect and can harm the kidneys.
- Lithium – levels rise; needs monitoring.
- Gentamicin, amikacin – higher risk of hearing and kidney damage.
- Laxatives, steroids – more potassium loss. Spironolactone or potassium supplements – your doctor balances these.
Frequently asked questions
When should I take Lasix 40?
In the morning, so that the heavy urination happens during the day. If a second dose is prescribed, take it in the early afternoon, not at bedtime.
How quickly does Lasix work?
The tablet starts working within about an hour and the effect lasts around 6 hours. You will pass a lot of urine during that time.
Can I take Lasix 40 with alcohol?
Avoid it. Alcohol dehydrates you further and drops blood pressure, and the combination can make you faint.
Does Lasix lower potassium?
Yes, furosemide makes you lose potassium in the urine. Your doctor will check blood levels and may add a potassium supplement or spironolactone. Report weakness, cramps or palpitations.
Lasix vs Aldactone – what is the difference?
Lasix (furosemide) is a strong loop diuretic that removes a lot of fluid quickly but loses potassium. Aldactone (spironolactone) is milder and saves potassium. They are often combined in heart failure and cirrhosis.
Is Lasix 40 safe in pregnancy?
It is avoided in pregnancy unless there is a serious reason such as heart failure, and only under a specialist. Tell your doctor if you are pregnant.
How much water should I drink on Lasix?
Follow your doctor's limit. In heart failure or cirrhosis you may be asked to restrict fluids; in hot weather or with diarrhoea you may need a little more. Do not guess – ask.
Can I take Lasix 40 for weight loss or swelling after standing all day?
No. Furosemide removes water, not fat, and misuse causes dangerous dehydration and salt loss. It is a Schedule H medicine for diagnosed heart, kidney and liver conditions.
Can I take Lasix with Telma or ramipril?
Yes, this is common in heart failure, but blood pressure can drop sharply at first. Your doctor usually starts with low doses and checks kidney function.
Sources
- NHS – Furosemide (19 October 2026)
- NPPA Pharma Sahi Daam (ceiling prices) (19 October 2026)
- PMBI Jan Aushadhi Product & MRP List (19 October 2026)
Medyzen Editorial Team · Last updated
This page is general information, not medical advice. Do not start, stop or change a medicine without asking a doctor or pharmacist. Terms