Loop Diuretics Flashcards
Give some examples of loop diuretics
Furosemide and Bumetanide
How do loop diuretics work?
Work in the ascending loop of Henle
Block the Na/K/Cl channels from working so reabsorbtion into epithelial cells is blocked and thus intraluminal levels increase
This results in salt, water and potassium excretion
ALSO causes vasodilation of capacitance veins reducing pre-load helping in HF
What are the common uses of loop diuretics?
- Acute pulmonary oedema - along with oxygen and nitrates for symptomatic relief of breathless ness (used in pulmonary oedema due to LVF as well)
- Chronic heart failure - reduce fluid overload
- Other oedematous states - liver failure and renal failure
- Resistant hypertension
What are the contra-indications of using loop directs?
Hypovalamic patiens
Dehydrated patients
Hypokalamic patients
When should you use loop directs with caution?
Hypokalaemia/Hyponatramic patients
Patients at risk of hepatic encephalopathy (hypokalaemia can worsen coma)
When taken chronically can exacerbate gout!
What are the common interactions with loop diuretics?
Any drugs that are excreted by the kidney;
- Lithium: decrease excretion so increased levels
- Digoxin: hypokalaemic levels can cause digoxin toxicity
- Aminoglycoside Abx Increase otoxocity and nephrotoxicity
- NSAIDs may reduce effects of loop diuretics
What are the common side effects of loop diuretics?
Dehydration
Hypotension
Low electrolyte state (hypo, natraemic, kalaemic, chlor, mag, cal) –> METABOLIC ALKALOSIS
Affects endolymph in ear so at high doses can lead to tinnitus and hearing loss
Should you monitor patients on loop diuretics?
For safety, periodic monitoring of serum sodium, potassium and renal function is also advisable, particularly in the first few weeks of therapy.
When should patients take their tablets?
Morning so diuretic effects do not cause them to wake up in the night
