Spironolactone is a diuretic, also known as a 'water tablet'.
It will make you go to the toilet more often to pass urine.
The most common side-effect is a mild stomach upset. This is not usually troublesome.
|Type of medicine||Aldosterone antagonist diuretic, potassium-sparing diuretic|
|Used for||Fluid retention|
|Also called||Aldactone®; |
Combination brands: Lasilactone® (spironolactone with furosemide); Aldactide® (spironolactone with hydroflumethiazide - co-flumactone)
Spironolactone is used to treat fluid retention (oedema) caused by liver disease, kidney problems or heart failure. Oedema occurs when fluid leaks out of your blood vessels, causing swelling in the tissues of your lungs, feet or ankles. This makes you feel breathless or your legs feel puffy. Spironolactone prevents a build-up of fluid in your body by increasing the amount of urine your kidneys produce. It is also used to treat some other conditions which cause fluid retention, such as a disorder called primary hyperaldosteronism.
Spironolactone is known as a potassium-sparing diuretic. Unlike some other diuretics, it does not cause your body to lose potassium. Diuretics are sometimes referred to as 'water tablets'.
Spironolactone is often used alongside other diuretics. When it is used like this, it may be prescribed as a combination product, such as in Lasilactone® (spironolactone with furosemide) and Aldactide® (spironolactone with hydroflumethiazide). Combinations like these help to reduce the number of tablets you need to take each day.
Before taking spironolactone
Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking spironolactone it is important that your doctor or pharmacist knows:
- If you are pregnant, trying for a baby or breastfeeding.
- If you have kidney problems.
- If you are being treated for prostate cancer.
- If you have a problem with your adrenal glands, called Addison's disease.
- If you have a rare inherited blood disorder, called porphyria.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
- If you have ever had an allergic reaction to a medicine.
How to take spironolactone
- Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about spironolactone and a full list of side-effects which you may experience from taking it.
- Take spironolactone exactly as your doctor has told you. The usual dose varies from 25 mg to 200 mg. Depending upon which dose is right for you, you may be asked to take several tablets a day but these are generally taken at the same time.
- Take the tablets with or just after a meal.
- Spironolactone is commonly prescribed just once daily and you can generally take the dose at a time to suit you. However, diuretics are best taken no later than mid-afternoon. This is because you will find you may need to go to the toilet a couple of times after taking them and this could disturb your sleep if you take it late in the day.
- If you have been prescribed more than one tablet of spironolactone a day and told to take them at different times, make sure you take your last tablet no later than 6 pm.
- If you forget to take a dose, take it as soon as you remember. However, if it is after 6 pm in the evening, skip the missed dose and continue as usual the next day. Do not take two doses at the same time to make up for a missed dose.
Getting the most from your treatment
- Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. The salt balance in your bloodstream may be upset by diuretics and your doctor will want you to have a blood test from time to time to check for this.
- Diuretics help you to lose water, so you can breathe or move more easily. If, however, you lose too much fluid, you may become dehydrated. This will make you feel thirsty and make your skin look and feel dry. Let your doctor know if this happens, as your dose may need to be adjusted.
- Another sign of dehydration with spironolactone is rapid weight loss after starting the tablets. Speak with your doctor if you notice this happening.
- Because spironolactone is a potassium-conserving diuretic, you should try to avoid things with a high potassium content, such as 'salt substitutes' or low-sodium salt. This is so the level of potassium in your body does not become too high.
- Treatment with diuretics is usually long-term, so continue to take these tablets unless you are advised otherwise by your doctor.
- If you buy any medicines, check with a pharmacist that they are suitable to take with your other medicines.
- If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.
Can spironolactone cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.
|Spironolactone side-effects||What can I do if I experience this?|
|Feeling sick (nausea) or being sick (vomiting)||Stick to simple meals - avoid rich or spicy foods|
|Feeling tired, dizzy, or sleepy||If this happens, do not drive and do not use tools or machines until you feel better|
|Sexual problems, breast discomfort and enlargement, feeling confused, irregular periods, confusion, sweating, cramps, hair loss or unwanted hair growth, and skin rash||If any of these become troublesome, speak with your doctor|
If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.
How to store spironolactone
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else has taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
Manufacturer's PIL, Aldactone® 25 mg, 50 mg and 100 mg Tablets; Pfizer Limited, The electronic Medicines Compendium. Dated June 2022.
Medicines Complete BNF 85th Edition; British Medical Association and Royal Pharmaceutical Society of Great Britain, London.