Urology Drugs - Werner Flashcards
What are the important drugs and substances that are ACTIVELY secreted in the PCT?
acids - probenicide, sulphinpyrazone
bases
What does probenicide compete with in the PCT?
penicillin
What does sulphinpyrazone compete with in the PCT?
uric acid
What kind of drugs do carnivores have delayed elimination of?
low pKa drugs
What chemicals have an effect on mesangial cells?
atrial natriuretic peptide - relax
sympathetic - contract
angiotensin 2 - constrict
What do carboanydrase inhibitors do?
increase excretion of bicarbonate with accompanying Na, K, and H2O
What are carboanhydrase drugs used to treat?
glaucoma
What is an example of carboanhydrase inhibitor?
acetazolamide
What is the effect of carboanhydrase on the urine?
mild alkaline urine –> metabolic acidosis
What part of the nephron is responsible for the countercurrent system?
loop of Henle
What parts of the loop of henle are water permeable?
descending limb
What are the most powerful diuretic drugs?
loop diuretics - furosemide, bumetanide, torasemide
What is the MOA of loop diuretic drugs?
inhibit Na/K/Cl carrier
How does loop diuretic drugs cause metabolic alkalosis?
increased Na in DT –> increased loss of H and K
What other molecules does loop diuretics affect?
increased loss of Ca and Mg, decreased loss of uric acid
What are the pharmacokinetic aspects of loop diuretics?
readily absorbed from GI, strongly protein bound, metabolized in liver
What are the SE of loop diuretics?
hypokalemia (and metabolic alkalosis, hypovolemia, hypotension)
What happens in the distal tubule?
active Na/Cl transport (dilution)
excretion of H and K (by Na/K pump)
calcium excretion
What are the 2 thiazide diuretics?
chlorothiazide and hydrochlorothiazide
What is the MOA of chlorothiazide?
blocks Na/Cl symport in DT
What other molecules does thiazide drugs effect?
K loss, excretion of uric acid and Ca decreased, excretion of Mg increased
What are the extra-renal effects of thiazide drugs?
vasodilation, hyperglycemia, reduce bone loss
What happens when thiazide drugs are used in hypertensive states?
initial fall in BP = increase in urine volume
later phase = direct action on BV
What are the clinical uses for thiazide diuretics?
hypertension, mild HF, central or nephrogenic diabetes insipidus
What are the renal SE of thiazides?
hypokalemia, metabolic alkalosis, increased uric acid in plasma
What are the non renal SE of thiazides?
hyperglycemia, increased plasma cholesterol, male impotence, hypersensitivity rxns
What do thiazide diuretics compete with to be excreted in the kidney?
uric acid
What do the principal cells reabsorb in the CD? What do they secrete?
Absorb: Na
Secrete: K
What do the intercalated cells do in the CD?
secrete H
What influences Na/Cl absorption in the CD?
aldosterone
What influences water reabsorption in the CD?
ADH/vasopressin
What is the quick effect of aldosterone on the CD?
stimulation of Na/H exchanger (membrane receptors)
What is the delayed effect of aldosterone on the CD?
cell receptors –>proteins that activate sodium channels
What drugs block the delayed effect of aldosterone in the CD?
amiloride and triamterene
What diuretic is a aldosterone receptor antagonist?
spironolactone
What increases the diuretic effect of K sparing diuretics?
high sodium load or aldosterone is high
What are the 2 clinical uses of K sparing diuretics?
increase K secondary to CHF
edema and ascites
What is the active metabolite of spironolactone?
canrenone - long half life
What are the SE of spironolactone?
GI, hyperkalemia, gynaecomastia, menstral, testicular, peptic ulcers
Which is more poorly absorbed? triamterene or amiloride?
amiloride
What do PGE2 and PGI2 influence on hemodynamics?
vasodilation in response to AG2 and norepinephrine mediated vasoconstriction
What influence does PGE2 and PGI2 have on renal control of NaCl and water?
increase renal blood flow and natriuresis(excretion of sodium)
What are the clinical indications of osmotic diuretics?
intracranial and intraocular pressure
prevention of acute renal failure
What are the side effects of osmotic diuretics?
transient expansion of ECF
What receptor does telmisartan bind to?
AT1 receptors
What kind of molecule is telmisartan?
lipophilic weak acid, binds reversibly
What drug can treat benign prostatic hyperplasia?
finasteride
What types of drugs should be used for acute prostatitis?
basic drugs (erythro, trimetho) lipophilic drugs (flouro, chloram, TMPS)
What types of antibiotics should be used for cystitis?
small spectrum, cidal
What drugs have a effect on the bladder for incontinence?
parasympathicolytics, sympathomimetics
What types of drugs will have effects on the spincter of the bladder for incontinence?
smpathomimetics, oestrogens
What can treat urethral hypertonicity?
phenoxybenzamine, prazosine, diazepam, dantrolene
What is another name for urethral hypertonicity?
detrussor-urethral dyssynergia
