Loop Diuretic Medicine
How to Loop Diuretics work, and what are they used to treat?
Originally published on: April 6th, 2017. Last modified on April 21st, 2022
A loop diuretic is a medicine taken to treat nocturia and is usually taken in the morning.
They work by making the kidneys pass out more urine, thus reducing your visits to the toilet during the night. Diuretic medicine increases the production and flow of urine from your body so you will find that you need to visit the toilet more frequently during the day. This effect will usually pass within 6 hours of taking the medication.
Loop diuretics are not licensed to treat nocturia, which means that the medication may not have undergone clinical trials (a type of research that tests one treatment against another) to see if it is effective and safe in the treatment of nocturia.
Your GP or specialist may suggest an unlicensed medication if they think the medication is likely to be effective and the benefits of treatment outweigh any associated risk. If your GP is considering prescribing a loop diuretic, they should tell you that it is unlicensed and will discuss the possible risks and benefits with you.
Everyone’s reaction to a medicine is different. Side-effects experienced on loop diuretics are uncommon, but the higher the dosage the greater the risk of side effects developing.
You may experience some of the side effects listed below or none at all. If you are having problems with this medicine, it’s important to tell your GP immediately.
Serious possible side-effects include:
- The salt balance in the bloodstream is sometimes upset which can cause a low blood level of potassium, sodium, and magnesium, and a high level of calcium. These effects may cause weakness, confusion and, rarely, abnormal heart rhythms to develop. You may be advised to have a blood test to check for these problems.
- If you have diabetes or gout, these conditions may be made worse by diuretics.
- An upset stomach
- Dizziness on standing (due to too low blood pressure).
For more information about this medication please visit Patient.info.
If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call NHS non-emergency number on 111 (You should use the NHS 111 service if you urgently need medical help or advice but it’s not a life-threatening situation)