Furosemide

• The dose of furosemide will be different for different people.
• Oedema (excess fluid): The usual dose for adults is 20 to 40 mg a day. Some people may need higher doses. Your healthcare provider will tell you how long to take furosemide for.
• High blood pressure: The usual dose for adults is 40 to 80 mg a day. Treatment is usually long term.
• Always take your furosemide exactly as your healthcare provider 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.

• Once a day dosing: Furosemide is usually taken once a day. It's best taken in the morning so it works during the day.
• Twice a day dosing: Some people are prescribed a second dose, which should be taken 6 to 8 hours after the first dose. For example, if you take a dose at 8 am your next dose can be taken at 2 pm.
• Timing: It’s best not to take a dose of furosemide too late in the day because you'll need to pee within a few hours of taking it. You don’t want to disturb your sleep by needing to go to the toilet during the night. Read more about tips for taking diuretics. 
• Food: If possible, try to take furosemide on an empty stomach, 1 hour before or 2 hours after food.
• Missed dose: If you forget to take your dose, take it as soon as you remember. But if it's late in the afternoon, skip the missed dose and continue as usual the next day. Don't take double the dose.

Taking furosemide with pain medicines

Be careful when taking some pain relief medicines. Taking NSAIDs, such as ibuprofen and diclofenac, together with blood pressure medicines, can be harmful to your kidneys. This is called the ‘triple whammy’. NSAIDs can also be found in some cold and flu medicines. 

If you're taking furosemide with other blood pressure medicines, such as ACE inhibitors or ARBs, tell your healthcare provider or pharmacist before starting NSAIDs. Talk to them about safe pain-relief options for you.

Image credit: Healthify He Puna Waiora

Read more about:

• Examples of ACE inhibitors and ARBs
• The triple whammy.

Some other things to know when you're taking furosemide

• Have a sick day plan: If you have diarrhoea (runny poo) or are vomiting (being sick) from a stomach bug, or you're dehydrated from another illness, it’s important to let your healthcare provider know. They may advise you to stop taking furosemide for a few days and start again when your eating and drinking returns to normal.
• Alcohol: Furosemide doesn't directly interact with alcohol. This means that most people could have the occasional drink while taking it without any serious problems. However, if furosemide makes you feel dizzy or sick (nausea), don't drink alcohol as it will make you feel worse.
• Sunlight: Protect yourself from too much sunlight while being treated with furosemide. Always cover up and apply a thick layer of broad spectrum sunscreen (at least SPF 30) when you're outside. Don't use sunbeds.
• Monitoring: You may need blood tests while taking furosemide to check the amount of potassium and sodium in your blood, and to see how well your kidneys are working.
• Interactions: Furosemide may interact with other medicines, herbal supplements and rongoā Māori, so check with your healthcare provider or pharmacist before starting furosemide and before starting any new products.
• Pregnancy or breastfeeding: Talk to your healthcare provider if you're pregnant, planning a pregnancy or want to breastfeed.
   

Like all medicines furosemide can cause side effects, although not everyone gets them. If you're concerned about any symptoms you think might be related to your medicine, talk to your healthcare provider. The information below offers some guidance but doesn’t include all possible side effects.

Common side effects

Tell your healthcare provider if these side effects bother you.

• Needing to pee more often. It's a good idea to know where the nearest toilets are when you’re away from home.
• Nausea (feeling sick) or having a sore stomach. Take your tablets with or just after food.
• Feeling light-headed or dizzy. Don’t drink alcohol. Be careful when driving or using tools until you know how this medicine affects you.
• 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're an older adult.

Tell your healthcare provider immediately or phone Healthline free on 0800 611 116 if these occur

• Signs and symptoms of gout such as pain, redness and swelling in a joint (eg, your big toe, wrist, elbow or knee). Furosemide may raise uric acid levels in your blood and cause an acute attack of gout for some people.
• Signs of dehydration (losing too much salt and water) such as muscle cramps, weakness, dry mouth, feeling thirsty all the time or passing less urine than usual.
• Trouble with hearing such as a ringing or buzzing sound in your ears, reduced or loss of hearing.
   

Phone 111 for an ambulance or go to your nearest accident and emergency (A&E) clinic if these occur

• Signs of an allergic reaction such as itchy skin, and rash, swollen lips or tongue, problems breathing, like a tight chest or shortness of breath.

Read more about medicines and side effects and reporting a reaction you think might be a side effect.