How does it work?
Inspra tablets contain the active ingredient eplerenone, which is a type of medicine called an aldosterone antagonist.
Eplerenone works by blocking the actions of a hormone in the body called aldosterone. This hormone is produced by glands found above the kidneys called the adrenal glands. Aldosterone acts in the kidneys, where it is involved in controlling the balance of salt and water in the body; it is also involved in the control of blood pressure and heart function.
Aldosterone is involved in the development and progression of heart failure, including heart failure that can occur following a heart attack. Heart failure is a weakening in the pumping action of the heart, usually involving the left side of the heart.
By blocking the action of aldosterone, eplerenone reduces the changes in the body that lead to worsening of the heart failure. It reduces the symptoms of heart failure, for example breathing difficulties and fatigue, and also reduces the risk of hospitalisation and death from heart failure.
What is it used for?
- Chronic mild heart failure.
- Heart failure in people who have recently had a heart attack. Eplerenone is used in combination with other medicines that are normally used following a heart attack, including beta-blockers. Treatment with eplerenone should be started 3 to 14 days after the heart attack.
How do I take it?
- Inspra tablets can be taken either with or without food. They should be swallowed with a drink of water.
- The tablets are usually taken once a day (every other day if you have moderate kidney problems). Follow the instructions given by your doctor. These will be printed on the dispensing label that your pharmacist has put on the packet of medicine.
- If you forget to take a dose take it as soon as you remember, providing there is still longer than 12 hours until your next dose is due. However, if it's nearly time for your next dose, skip the tablet you missed and just take your next dose as normal. Don't take a double dose to make up for a missed dose.
- This medicine may make some people feel dizzy. You should take care when driving or operating machinery until you know how this medicine affects you and you are sure you can perform such activities safely.
- This medicine can cause the level of potassium in your blood to rise, particularly if you are elderly or have kidney problems or diabetes. You will need to have a blood test to check the level of potassium in your blood before treatment with this medicine is started. This blood test should be repeated one week and one month after treatment is started and whenever your dose is changed.
- If you experience any of the following symptoms while taking this medicine you should inform your doctor promptly, so that the amount of potassium in your blood can be checked: muscle cramps, diarrhoea, nausea, dizziness or headache.
Use with caution in
- Elderly people.
- People with decreased kidney function.
- People with decreased liver function.
Not to be used in
- People with a high level of potassium in their blood (hyperkalaemia).
- People with severely decreased kidney function.
- People with severely decreased liver function.
- People taking potassium supplements, potassium-sparing diuretics, ketoconazole, itraconazole, nelfinavir, ritonavir, clarithromycin, telithromycin or nefazodone.
- People already taking an ACE inhibitor medicine (eg captopril) AND an angiotensin receptor blocker medicine (eg losartan).
- Inspra tablets contain lactose and may not be suitable for people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.
- This medicine is not recommended for children and adolescents under 18 years of age as it has not been studied in this age group.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- The safety of this medicine for use during pregnancy has not been established. It should be used with caution during pregnancy, and only if the expected benefit to the mother is greater than any possible risk to the developing baby. Seek medical advice from your doctor.
- It is not known if this medicine passes into breast milk. As a result, the manufacturer recommends that mothers who need treatment with this medicine should not breastfeed, and bottlefeed their infants instead. Seek further medical advice from your doctor.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
Common (affect between 1 in 10 and 1 in 100 people)
- Increased level of potassium in the blood (hyperkalaemia - see warning section above).
- Low blood pressure.
- Diarrhoea or constipation.
- Rash or itching.
- Muscle spasms or pain.
- Heart attack.
- Abnormal kidney function.
Uncommon (affect between 1 in 100 and 1 in 1000 people)
- Difficulty sleeping (insomnia).
- Heart problems, such as irregular heart beat, increased heart rate or heart failure.
- Underactive thyroid gland (hypothyroidism).
- A drop in blood pressure that occurs when moving from lying down to sitting or standing and results in dizziness and light headedness (postural hypotension).
- Blood clots in the leg (arterial thrombosis).
- Sore throat (pharyngitis).
- Flatulence (wind).
- Increased sweating.
- Back pain.
- Reduced sensation or numbness.
- Feeling weak or generally unwell.
- Raised levels of white blood cells called eosinophils (eosinophilia).
- Elevated levels of glucose, cholesterol or triglycerides in the blood.
- Decreased level of sodium in the blood (hyponatraemia).
- Inflammation of the kidneys (pyelonephritis).
- Inflammation of the gallbladder (cholecystitis).
- Enlargement of the breasts in men.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.
If any of the following medicines are taken in combination with eplerenone it could cause the amount of potassium in the blood to rise too high. These should therefore be avoided where possible. If your doctor considers them necessary the level of potassium in your blood should be monitored:
- ACE inhibitors, eg captopril (eplerenone must not be used in combination with an ACE inhibitor AND an angiotensin receptor blocker)
- angiotensin-II receptor blockers, eg losartan (eplerenone must not be used in combination with an ACE inhibitor AND an angiotensin receptor blocker)
- other aldosterone antagonists, eg spironolactone
- potassium-sparing diuretics, eg amiloride, triamterene (these must not be taken with eplerenone)
- potassium salts, eg potassium citrate for cystitis
- potassium supplements (these must not be taken with eplerenone)
- potassium-containing salt substitutes, eg Lo-salt
You should not take non-steroidal anti-inflammatory drugs (painkillers such as ibuprofen, naproxen,diclofenac or indometacin) while you are taking eplerenone, unless recommended by your doctor. This is because NSAIDs can affect your kidney function and the level of potassium in your blood and could increase the risk of side effects from your eplerenone. Your doctor will need to check your kidney function before prescribing you an NSAID.
Eplerenone may increase the blood level of lithium and for this reason, it is not normally recommended for people taking lithium. People who need to take this medicine in combination with lithium should have the level of lithium in their blood closely monitored. Tell your doctor if you experience any side effects that could suggest your lithium level has risen too high, for example loss of appetite, blurred vision, slurred speech, muscle weakness, drowsiness, unsteadiness or muscle twitching.
Eplerenone may increase the level of digoxin in the blood. If you are taking this medicine in combination with digoxin you should let your doctor know if you experience any side effects that could suggest your digoxin level has risen too high, for example feeling sick or vomiting, diarrhoea, dizziness, blurred vision or a yellow tinge to your vision. Your doctor may want to check your digoxin level.
Eplerenone may enhance the blood pressure lowering effect of medicines used to treat high blood pressure (antihypertensives) and medicines that can lower blood pressure as side effect. If you are taking other medicines that can lower blood pressure in combination with eplerenone and you frequently feel dizzy, you should let your doctor know as your medicine doses may need adjusting. Examples of some medicines that can lower blood pressure are listed below:
- alpha-blockers such as prazosin or doxazosin
- antipsychotic medicines such as chlorpromazine or haloperidol
- tricyclic antidepressants such as amitriptyline.
The following medicines can decrease the breakdown of eplerenone in the body, which could increase the risk of its side effects. Your doctor may lower your dose of eplerenone if you are also prescribed any of these:
- azole antifungals, such as fluconazole, itraconazole, ketoconazole (ketoconazole and itraconazole must not be taken with eplerenone)
- macrolide-type antibiotics, eg erythromycin, clarithromycin, telithromycin (clarithromycin and telithromycin must not be taken with eplerenone)
- nefazodone (must not be taken with eplerenone)
- protease inhibitors for HIV infection, such as ritonavir, lopinavir, saquinavir and amprenavir (ritonavir and nelfinavir must not be taken with eplerenone)
The following medicines can increase the breakdown of eplerenone in the body. As these could make it less effective, they are not recommended for use in combination with eplerenone:
- the herbal remedy St John's wort (Hypericum perforatum).
Corticosteriods such as hydrocortisone, dexamethasone and prednisolone can cause fluid and salt retention and so may oppose the therapeutic effect of eplerenone.
Other medicines containing the same active ingredient
There are currently no other medicines available in the UK that contain eplerenone as the active ingredient.