Flashcards in Pharmacology 3 Deck (43)
Are osmotic diuretics membrane permeable? And where is their major site of action?
They are membrane IMPERMEABLE = given IV
Major site of action is the proximal tubule (because this is where most iso-osmotic reabsorption of water occurs_
i.v. osmotic diuretic
Hyperglycemia and the use of iodine-based radiocontrast dyes in imaging may also result in which type of diuresis?
Carbonic anhydrase inhibitor
Type of drug used in
-glaucoma and following eye surgery
-prophylaxis of altitude sickness
-some forms of infantile epilepsy
Carbonic anhydrase inhibitors
Increase excretion of HCO3- with Na+, K+ and H2O – alkaline* diuresis and metabolic acidosis result
Carbonic anhydrase inhibitors
Lack of vasopressin secretion from the posterior pituitar
Neurogenic diabetes insipidus
Treatment for neurogenic diabetes insipidus?
Does desmopressin increase blood pressure?
Ethanol and nicotine effects on vasopressin?
Ethanol inhibits secretion of vasopressin and nicotine enhances
Inability of the nephron to respond to vasopressin?
Nephrogenic diabetes insipidus
-no current pharmacological treatment
Nephrogenic diabetes insipidus inheritance?
Drugs which inhibit vasopressin?
Canagliflozin, dpagliflozin and empaglifolzin
Most common adverse effects of SGLT2 inhibitors?
Genital bacterial and fungal infections
Treatment for acute urinary retention?
Immediately catheterise men and then offer alpha blocker before removing catheter
alpha blockers: alfuzosin, tamsulosin
Often presents in patients with chronic bladder outflow obstruction in association with uraemia, oedema, CCF, hypertension
This happens because you have retained urea, sodium and water =need to be diluted on excretion and you also have a defect in the concentrating ability of the kidney
Role of prostaglandins in obstruction
Ureter becomes blocked (e.g. by calculus) and then ureter releases prostaglandins in response
After how many months would calculus need intervention?
If not passed in 1 month then likely to require intervention
Treatment for infected hydronephrostomy?
Indications to treat calculus urgently?
Treatment for clot retention?
3-way irrigating haematuria catheter
Investigations for frank haematuria?
CT urogram and cystoscopy
Torsion of spermatic cord presentation?
Usually sudden onset of pain, sometimes previous episodes of self limiting pain
Act as competitive antagonists of vasopressin receptors?
These receptors mediate vasoconstriction
These receptors mediate H20 reabsorption in collecting tubule by directing aquaporin 2 (AQP2)-containing vesicles to the apical membrane
Blockade of V2 receptors and the effect on water and Na+?
ade of V2 receptors causes excretion of water without accompanying Na+ and thus raises plasma Na+ concentration
Used in SIADH to correct hyponatremia
Where is SGLT1 expressed?
In the intestine (enterocytes) and the kidney
Where is SGLT2 expressed?
Almost exclusively confined to the proximal tubule
S1 vs S2 segment of proximal tubule and glucose reabsorption?
S1 segment --> 90% of glucose reabsorption
S2/S3 segment --> reabsorb up to 10% of filtered glucose, respectively
Method of glucose reabsorption at apical membrane?
secondary active transport
Reabsorption of glucose at basolateral membrane?
Inhibition of SGLT2 results in glucosuria and this mimics which condition?
Familial renal glucosuria (FRG)
Canagliflozin, dapagliflozin and empagliflozin are what type of drug?
What are prostaglandins formed from?
Formed from fatty acid arachidonic acid (by the cyclo-oxygenase enzymes)
Where is PGE2 made?
Where is PGI2 (prostacyclin) made?
Act as vasodilators, are natriuretic, and are synthesised in response to ischaemia, mechanical trauma, angiotenin II, ADH and bradykinin?
Prostaglandins and afferent and efferent arteriole?
Vasodilator effect on AFFERENT arteriole
Vasoconstrictor effect on efferent arteriole (because releases renin that leads to increased levels of angiotensin II)
Which type of drug may precipitate acute renal failure?