Furosemide

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)
  • Loop diuretic
  • 'Water' tablet or 'water pill'
  • Frusemide
  • Diurin®
  • Lasix®
  • Urex Forte®

What is furosemide?

Furosemide is a diuretic, which means it helps your body get rid of extra salt (sodium) and water. It works by increasing the amount of urine (pee) you make. Furosemide 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).

In New Zealand furosemide is available as tablets and liquid and can be given as an injection in the hospital.

Dose

  • The dose of furosemide will be different for different people.
  • Water retention (oedema): the usual dose is 20 to 40 milligrams a day. Some people may need higher doses.
  • High blood pressure: the usual dose is 40 to 80 milligrams a day.
  • Your doctor will advise you how long to take furosemide for.
  • 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. 
  • Furosemide 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. Read more about tips for taking diuretics
  • 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. But, if it is late in the afternoon, skip the missed dose and continue as usual the next day. Do not take double the dose.
  • If your tablets look different to your last supply, ask your doctor or pharmacist for advice.
Be careful when taking some pain relief medicines
Taking diuretics together with pain relief medicines called ‘non-steroidal anti-inflammatory drugs’ (NSAIDs) and medicines called ACE inhibitors or ARBs can be harmful to your kidneys (this combination of medicines is called the triple whammy). Read more: Be careful when taking some pain relief medicines

Precautions – before starting furosemide

  • Are you pregnant or breastfeeding?
  • Do you have difficulty peeing, or do you have prostate problems?
  • Do you have problems with your liver or kidneys?
  • Do you have gout or diabetes? These conditions can be made worse by furosemide.
  • Are taking any other medicines? This includes any medicines you are taking which you can buy without a prescription, as well as herbal and complementary medicines and medicines you can buy for pain relief.

If so, it’s important that you tell your doctor or pharmacist before you start furosemide. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Possible side effects

Like all medicines furosemide can cause side effects, although not everyone gets them. Often 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 lightheaded
  • Feeling faint when you stand up
  • Be careful when getting up from either lying down or sitting to avoid falls. These effects put you at risk of falls and injuries, especially if you 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 (losing 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

Interactions

Diuretics can interact with a number of other medicines and herbal supplements so check with your doctor or pharmacist before starting diuretics or before starting any new medicines.

Be careful when taking some pain relief medicines

Taking the group of pain relief medicines called ‘non-steroidal anti-inflammatory drugs’ (NSAIDs) can be harmful to your kidneys. Examples include: 

Taking NSAIDs together with diuretics and medicines called ACE inhibitors or ARBs can be harmful to your kidneys (this combination of medicines is called the triple whammy). If you are taking ACE inhibitors or ARBs and diuretics, tell your doctor or pharmacist before starting NSAIDs.

  • Examples of ACE inhibitors are captopril, cilazapril, enalapril, lisinopril, perindopril and quinapril.
  • Examples of ARBs are candesartan, irbesartan, valsartan and losartan.

Before buying NSAIDs for pain relief, check with your pharmacist whether these are safe for you.

Read more about NSAIDs, ACE inhibitors, ARBs and The triple whammy SafeRx

Learn more

The following links provide further information on furosemide.

FurosemideAmiloride and furosemide (Māori) New Zealand Formulary Patient Information
DiurinLasix Medsafe Consumer Information Sheets

References

  1. Furosemide New Zealand Formulary
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 13 Feb 2019