L16 - duiretics Flashcards
what is diuretics
drug that increase water or solute excretion
-overrides homeostatic processes
how do we regulate omso and volume balance in the body regarding urine
- we can adjust level of urine production to make sure the levels of osmo and volume is normal
what is osmotic diuretics and eg of it
like mannitol
- filtered through the golumerulus but not absorbed so the osmo in the tubular fluid increases.
- draws in water into the fluid so urine vol increases
how is glucose an osmotic diuretics
when there is an excess glucose, it’s excreted in the urine. but this increase osmo so water is also excreted
why could osmotic diuretics be used
- to reducde fluid in tissues for surgery
- prevents ceberal oedema (swelling) following neurosurgery
why is it bad to give a patient with heart failure an osmotic diuretic
this would make the fluid come out of the tissues and accumulate in the systematic circulation.
so the heart needs to work harder to pump the blood and the fluid around the body
how does diuretics work on tubule reabsorption
- secreted through proximal tubule
- cant be filtered because they are bound to a plasma protein
- act on different points of the nephron
how do loop diuretics work
inhibiting transport of NA, K, CL- ions
- water stays in the collecting duct and not absorbed by the body
side of loop duiretics
- dehydration,
- alkalosis - as the ions like Mg, Ca, H and K are being excreted so theres more neg ions in the body
- hypoalakemia
- deafness - if not prevented early, ions needed for APs in the sensory cells
therapy or treatments by using loop diuretics
- removes fluid-like oedema
- hyper calcaemia
- hypertension
- drug overdose - eliminates more toxic drug
what is thiazides
eg Bendroflumethiazide
- inhibits NA/Cl- transporter in the DCT
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side fof thiazides
-increased excretion of Mg, H and K
-decreased Ca excretion so distrupted electical activity
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therapy or treatments by using thiazides
hypertension so reduces blood vol and vascular R
what is K+sparing diuretics
-anatagonist for minercorticoid receptor
- inhibits aldosterone
inhibits Na absorption in the collecting duct but very small effect
side effect of K-sparing diuretics
hyperkalemia
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