Fichas
Diuretics (Loop)
Fichas del conjunto (5)
- 1Give eg's of & indications for loop diuretics.eg's: furosemide, bumetanide, torasemide
Indications:
• Relief of breathlessness in acute pulmonary oedema in conjunction with O2 & nitrates
• Rx of fluid overload in CHF
• Rx of fluid overload in other oedematous states, eg renal DS or liver failure - 2MOA of loop diuretics.Loop diuretics act principally on the ascending limb of the loop of Henle, where they inhibit the Na+/K+/2Cl−co-transporter. This protein is responsible for transporting sodium, potassium & chloride ions from the tubular lumen into the epithelial cell. Water then follows by osmosis. Inhibiting this process has a potent diuretic effect. In addition, loop diuretics have a direct effect on BD vessels, causing dilatation of capacitance veins. In acute HF, this reduces preload & improves contractile function of the ‘overstretched’ HT muscle. Indeed, this is probably the main benefit of loop diuretics in acute HF, as illustrated by the fact that the clinical response is usually evident before a diuresis is established.
- 3In which parts of the nephron do particular classes of diuretic work?
- 4SE's of loop diuretics.SE's:
• Dehydration
• Hypotension
• Hearing loss & tinnitus (affects a similar Na+/K+/Cl- transporter in inner ear) - 5CI's, cautions, & important interactions of loop diuretics.CI's:
• Hypovolaemia
• Dehydration
Cautions:
• Hepatic encephalopathy
• Hypokalaemia
• Hyponatraemia
• Gout
Important interactions:
Loop diuretics have the potential to affect drugs that are excreted by the kidneys. For example, lithium levels are^ due to reduced excretion. The risk of digoxin toxicity may also be^, due to the effects of diuretic-associated hypokalaemia. Loop diuretics can^ the ototoxicity & nephrotoxicity of aminoglycosides.