diuretics Flashcards
where do loop diuretics act
TAL
where do thiazide diuretics act
distal tubule
where does spironolactone and amiloride act
collecting tubule
what happens in the thick ascending loop
impermeable to water
active reabsorption of Na Cl
what is the function of ADH
increases permeability to water of the collecting duct. this means more can be reabsorbed into the blood producing more concentrated urine
what is the function of aldosterone
increases permeability of ions and water in the collecting duct
how is sodium reabsorbed in the distal nephron
swapped for K and H ions
how do diuretics work
cause naturesis which causes diuresis
what is furosemide (loop diuretic)
loop diuretic.
inhibits absorption of ions in the TAL
they inhibit the counter current multiplier which sets up the concentration gradient
causes loss of K and H and increase in bicarbonate
increase renal prostaglandins which change renal blood flow
moderated in DCT which exchanges for sodium for K/H
very effective diuretic
how do potassium sparing diuretics work. eg spironolactone
•Inhibits aldosterone-sensitive sodium pump by renal prostaglandin production
how do carbonic anhydrase inhibitors work
inhibit transport of bicarbonate from the PCT into the interstitium leading to less sodium reasorbtion - very weak
how are diuretics used in heart failure
decrease pre load which decreases blood pressure
decreases venous return
decreases oedema
what are the symptoms of inappropriate ADH secretion
- Nausea and/or vomiting
- Cramps/tremors
- Depressed mood, irritability, personality change, memory issues, hallucinations
- Seizures
- coma
what are the causes of inappropriate ADH secretion
•CNS – infections, brain tumour or bleed, hydrocephalus, Guillain-Barre, MS •Cancers – Carcinomas of lung, GIT, GUT; lymphomas; sarcomas •Medication – antibiotics - some anti -epletics - some major sedatives - oxytocin - MDMA ( Ecstasy) •Lung disease •Hypothyroidism or parathyroidism •HIV •Sarcoid
how is inappropriate ADH secretion treated
fluid restriction
saline
tolvaptan
what might polycythaemia be caused by
kidney tumour causing increase EPO production
what is AZT for
anti retroviral therapy
what hormones are produced in the adrenal cortex
- Glucocorticoids e.g. cortisol
- Mineralocorticoids e.g. aldosterone
- Androgens
what hormones are produced in the adrenal medulla (catecholamines)
- adrenaline
* noradrenaline
what is beclometasone
used to treat asthma, psoriasis, hayfever etc
steroid- glucocorticoid
what is prednisolone used to treat
autoimmune and inflammatory disorders e.g. RA, asthma UC- glucocorticoid
what is dexamethasone
glucocorticoid- anti inflammatory used in allergy and asthma
what is fludrocortisone
mineralcorticoid-low blood pressure or to replace aldosterone
addison’s disease
where is aldosterone produced
adrenal cortex
