Sounds like 'few-ROW-seh-mide'

Easy-to-read medicine information about furosemide – what is it, how to take furosemide safely and possible side effects.

Type of medicine Also called
  • Diuretic (causes you to pass more urine)
  • 'Water' tablet or 'water pill'
  • Frusemide
  • Diurin®
  • Lasix®
  • Urex Forte®

What is furosemide?

  • Furosemide is a diuretic, which means it causes you to pass out more urine from your kidneys. It helps your body to get rid of extra salt and water.
  • It is used to lessen extra fluid in the body (called oedema) caused by conditions such as heart failure, liver disease, or kidney disease. This can reduce symptoms such as swelling in your ankles or feet, or shortness of breath. 
  • Furosemide is also used to treat high blood pressure (hypertension).
  • Furosemide is available as tablets, oral liquid and injection.


  • The dose of furosemide will be different for different people.
  • The usual dose for water retention is 20 to 40 milligrams a day. Some people may require higher doses.
  • The usual dose for high blood pressure is 40 to 80 milligrams a day.
  • Always take your furosemide exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much furosemide to take, how often to take it, and any special instructions.

How to take furosemide

  • Furosemide is usually taken once a day, in the morning. Some people may need a second dose, at lunchtime. 
  • Because furosemide will cause you to pass urine often and usually starts working within 1 hour of taking your dose, it is best taken in the morning so it works during the day and your sleep is not disturbed by you needing to get up to go to the toilet during the night.
    But, if you want to go out in the morning and don't want to have to find a toilet, you can delay taking your dose until lunch-time or early afternoon. 
  • You can take furosemide with or without food.
  • Limit or avoid drinking alcohol while you are taking furosemide. Alcohol may increase your chances of getting side effects such as dizziness.
  • If you forget to take your dose, take it as soon as you remember that day. However, if it is after 4 pm in the afternoon, you should skip the forgotten dose and continue as usual the next day. Do not take double the dose.

Possible side effects

Like all medicines, furosemide can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sick (nausea)
  • Stomach upset

  • These are quite common when you first start taking furosemide, and usually go away after the first few days
  • Try taking your furosemide dose with or after food
  • Tell your doctor if troublesome
  • Dizziness
  • Feeling light headed
  • Feeling faint when you stand up
  • Be careful when getting up from either lying down or sitting to avoid falls. These effects puts you at risk of falls and injuries, especially if your are elderly
  • Be careful when driving or using tools until you know how this medicine affects you
  • Trouble with hearing such as ringing in the ears, reduced hearing or deafness (loss of hearing)
  • Tell your doctor
  • Signs of dehydration (loosing too much salt and water) such as muscle cramps, weakness, dry mouth, thirst or passing unusually reduced amounts of urine
  • Tell your doctor
  • Signs of an allergic reaction such as skin rashes, itching, blisters, peeling skin, swelling of the face, lips, mouth or have problems breathing
  • Tell your doctor immediately or ring HealthLine 0800 611 116


Furosemide can interact with a number of medications and herbal supplements so check with your doctor or pharmacist before starting furosemide or before starting any new medicines. 

Also check with your pharmacist before taking anti-inflammatories that can be bought over-the-counter, such as diclofenac (e.g. Voltaren Rapid), ibuprofen (e.g. Nurofen), naproxen (e.g. Naprogesic).

Learn more

The following links provide further information on furosemide.

Medsafe Consumer Information Sheets: Diurin , Lasix

New Zealand Formulary Patient Information: Furosemide , Amiloride and furosemide

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft. Health Navigator NZ Last reviewed: 22 Oct 2015