Diuretics help to reduce fluid overload in heart failure. Loop diuretics are preferred for acute exacerbations. Thiazide-like diuretics are now recommended by NICE for the treatment of hypertension in newly diagnosed patients.
Thiazide-like diuretics are fully effective only when renal function is normal or only minimally impaired and are contraindicated in severe impairment. Loop diuretics may be required in hypertensive patients with severe renal impairment.
Do not prescribe diuretics routinely later than early afternoon.
Thiazide-like and loop diuretics can cause serum-potassium levels to fall in some patients, particularly during the first few weeks of treatment. Hypokalaemia should be treated appropriately if it occurs. A potassium-sparing diuretic is generally more effective and convenient than potassium chloride supplements.
Regular review of diuretic use is desirable to confirm continued need and to monitor adverse effects such as dehydration, which may cause renal impairment particularly in the elderly. Use of potassium supplements or potassium-sparing diuretics should be re-assessed regularly by measuring serum-potassium levels.
The action of indapamide is progressive and the reduction in blood pressure may continue and not reach a maximum until several months after the start of therapy.
Indapamide is claimed to lower blood pressure with less metabolic disturbance than other diuretics particularly less aggravation of diabetes mellitus.
Metolazone and loop diuretics appear to have a synergistic effect when combined. Profound diuresis can occur so monitor patient carefully. Use intermittently based on achievement of a target weight. Reduce dose or stop treatment until target weight exceeded again.
If a diuretic is to be initiated or changed. Existing patients should remain on bendroflumethiazide.
NB Indapamide MR is not recommended as limited evidence of additional benefits and higher cost.
Oedema resistant to large doses of loop diuretics alone.
This product has been discontinued by the manufacturers but imported sources are now available. Local specialist opinion is to use bendroflumethiazide as an alternative in line with the recommendations of the British Society for Heart Failure.
Furosemide (40-60mg) has a similar effect to bumetanide (1mg) for most clinical uses. Diuresis is complete within 6 hours of oral administration with both drugs therefore if necessary they can be given twice in one day without disturbing sleep.
Bioavailability of oral bumetanide is sometimes better than furosemide particularly in patients with right-sided congestive heart failure associated with liver/ splanchnic congestion.
The therapeutic effect of loop diuretics can be measured by monitoring the patient’s weight on a daily basis.
In acute heart failure, small doses of parenteral loop diuretics are valuable (onset of action approximately 5 minutes after IV injection).
Large doses of loop diuretics may be required in renal failure.
IV Guide available through 'Injectable Medicines Guide' link on front page of INsite.
Potassium-sparing diuretics and aldosterone antagonists
Amiloride and spironolactone are weak diuretics if given alone, but their diuretic and antihypertensive effects are additive with those of loop and thiazide diuretics. They should be used in preference to potassium supplements if hypokalaemia is a problem with loop or thiazide diuretics alone.
Combinations should not be used unnecessarily and in practice are often not justified when treating hypertension, as the risk of hyponatraemia is greater than with one agent alone.
Amiloride and spironolactone may take 2-3 days to become fully effective.
Potassium-sparing diuretics are contra-indicated in renal failure; the elderly may insidiously develop hyperkalaemia due to deterioration in renal function.
Close monitoring required if prescribed together with other agents that raise serum potassium. These include potassium supplements, ACE inhibitors and angiotensin-II antagonists. Non-steroidal anti-inflammatory drugs (NSAIDs) and ciclosporin may also increase the risk of hyperkalaemia. Serum potassium should be monitored 3 monthly and within 7-14 days after a dose change.
NICE recommends in patients with heart failure due to left ventricular systolic dysfunction who remain moderately to severely symptomatic despite optimal therapy of ACE inhibitors and β blocker. Specialist advice should be sought as monitoring required.
Can also be used when an aldosterone antagonist is clearly indicated (e.g. primary hyperaldosteronism or treatment of oedema and/or ascites in hepatic cirrhosis).
Evidence supports the use in patients admitted to CCU following an MI with proven left ventricular failure in addition to other treatment. Second line as an alternative to spironolactone in patients who have chronic heart failure or hypertension and suffer from gynaecomastia.
Combined loop or thiazide diuretic with a potassium-sparing agent should not be used indiscriminately. They are more expensive than diuretic alone and are more likely to cause hyponatraemia or other adverse reactions than a single agent.
Amiloride 5mg with furosemide 40mg
Proprietary brands are more costly
Amiloride 5mg with hydrochlorothiazide 50mg; (Moduretic)
Products that combine a diuretic with potassium chloride are not recommended because they often contain insufficient potassium (8-12mmol per tablet) to correct hypokalaemia.
Non Formulary Items
Indapamide SR (Natrilix-SR®)
Section Title (top level)
Section Title (sub level)
First Choice item
Non Formulary section
Display tracking information
Link to adult BNF
Link to children's BNF
Link to SPCs
Scottish Medicines Consortium
High Cost Medicine
Cancer Drugs Fund
Traffic Light Status Information
Drugs not recommended for use in the Leicestershire Health Community because of lack of evidence of clinical effectiveness, cost prioritization or concerns over safety.
All new drugs will be black until they have been through the appropriate approval process - then they will appear as a specific entry
Drugs which should be prescribed only by hospital specialists (clinical review by specialist as appropriate and annually as a minimum).
Drugs which would initially be prescribed by a hospital specialist and then by a GP where full agreement to share the care of each specific patient has been reached under a LMSG Shared Care Agreement (SCA). Specific patient monitoring or intervention required.
Drugs suitable to be initiated and prescribed in primary care only after specialist assessment and recommendation. A shared care agreement is not required.
Drugs for which GPs are able to take full responsibility for prescribing and monitoring subject to specified conditions e.g. prescribing in line with agreed LMSG guidance or able to demonstrate suitable competence see comments under individual entries.
Drugs for which GPs would normally take full responsibility for prescribing and monitoring. Drugs included in this list have been specifically considered by LMSG.