Unit 8.1 Diuretics Chapter 29 diuretic drugs

Flashcard maker : Lewis Gardner
QuestionAnswer
afferent arteriolesthe small blood vessels approaching the glomerlus
aldosteronea mineralocorticoid steroid hormone produced by the adrenal cortex that regulates sodium potassium balance
ascitesintraperitoneal accumulation of fluid, containing large amounts of portion and electrolytes
collecting ductthe most distal part of the nephron between the distal convoluted tubule and the ureters which lead to the urinary bladder
distal convoluted tubulethe part of the nephrotoxicity immidiately distal to the ascending loop of hence and proximal to the collecting duct
diureticsdrugs or other substances that tend to promote the formation and excretion of urine
efferent arteriolsthe small blood vessels exciting the glomerulus; at this point blood has completed its forting in the glomerulus
filtratethe material that passes through a filter; in the case of the kidney, the filter is the glomerular and the filtrate is the material extracted from the blood
glomerular capsulethe open, rounded, and most proximal part of the proximal convoluted tubule that surrounds the glomerulus and receives the filtrate from the blood
glomerular filtration rate (GFR)an estimate of the volume of blood that passes through the glomeruli of the kidney per minute
glomerulusthe cluster of kidney capillaries that mark the beginning of the nephron and is immediately proemial to the proximal convoluted tubule
loop of henlethe part of the nephron that is immediately distal to the proximal convoluted tubules
nephronthe functional filtration unit of the kidney, consisting of the glomerulus, proximal convoluted tubule, loop of hence, distal convoluted….
open angle glaucomacondition in which pressure is elevated in the eye because of obstruction of the outflow of aqueous humour
proximal convoluted (twisted) tubulethe part of the nephron that is immediately distal to the glomerulus and proximal to the loop of henle
diuretics are first line therapy forhypertension
kidneysfilter out toxic waste products from the blood while simultaneously conserving essential substances
balance between elimination of toxins, and retention of essential chemicals is maintained by thenephron
diuretics exert their effect on thenephrons
afferent arterioles mnemonicA is for approach and afferent
Efferent arteriol mnemonicE is for exit and efferent
the proximal convoluted tubule returns60-70% of the sedum and water from the filtered fluid back into the bloodstream
most potent diuretics arethe loop diuretics
potency of diuretics is a function ofwhere they act in the nephron to inhibit sodium and water resorption
the more sodium and water the diuretic inhibit thegreater the diuresis and consequently the greater the potency
Carbonic anhydrase inhibitors (CAIs)chemical derivatives of sulphonamide antibiotics, inhibit the activity of the enzyme carbonic anhydrase found in the kidneys, eyes, and other parts
carboni anhydrase inhibitors act atthe location of the carbonic anhydrase enzyme system along the nephron, primarily in the proximal tubule.
Acetazolamidemost commonly used CAI (carbon anhydrase inhibitor)
for sodium and water to be resorbed back into the bloodhydrogen myst be exchanged for it
carbonic anhydrase makeshydrogen ions for exchange with sodium and water – making little sodium and water resorbed into the blood, and eliminated with urine
CAI's reduce the formation ofhydrogen and bicarbonate (HCO3-)which results in reduction in the availability of the ions for active transport system
CAI's can inducerespiratory and metabolic acidosis – which can increase oxygenation during hypoxiaq
undesirable effect of CAI's isthe elevation of blood glucose levels which causes glycosuria in patients with diabetes
indications for CAI'streatment of glaucoma, edema, epilepsy, and high altitude sickness
Acetazolamide is also usedto manage edema secondary to heart failure that has become resistant to other diuretics
CAIs are much lesspotent diuretics than loop diuretics or thiazides
contraindications for sure of CAIs includehyponatremia, hypokalemia, severe kidney or liver dysfunction, adrenal gland insufficiency and cirrhosis
ADE of CAI's aremetabolic abnormalities such as acidosis and hypokalemia. Drowsiness, anorexia, paresthesias, hematuria, urticaria, photosensitivity and melena
loop diuretics have effects onkidney, cardiovascular, and metabolic, and activate kidney prostaglandins which result in dilation of the blood vessels of the kidneys, lungs and body
loop diuretics hemodynamic effect is inboth the preload and central venous pressures (filling pressures of the ventricles)
loop diuretics haverapid onset, which is useful when rapid diuresis is needed
loop diuretics have an advantage over thiazide diuretics in thatdiuretic action continues even when the creatinine clearance decreases below 25mL/min
loop diuretics can still work even whenkidney function diminishes
major ADE of loop diureticselectrolyte disturbance – prolonged admin of high dosages can also result in hearing loss stemming from ototoxicity although rare
loop diuretics indicated tomanage edema associated with heart failure and liver or kidney disease, manage hypertension and to increase kidney excretion of calcium in hypercal
contraindications to the use of loop diureticshepatic coma, severe electrolyte loss
loop diuretics also affect lab resultsincrease in serum levels of uric acid, glucose, alanine aminotransferase, and aspartate aminotransferase
osmotic diuretics (manitol, urea, organic acids, and glucose)works along the entire nephron. major site of action is the proximal tubule and descending limb of the loop of Henle
mannitol (most commonly used osmotic diuretic)increases osmotic pressure in the glomerular filtrate, which in turn pulls fluid, primarily water into the renal tubules from surrounding tissue
mannitol only produces a slightloss of electrolytes, especially sodium. therefore not indicated for patients with peripheral edema
mannitol may inducevasodilation, and when it does it increases both glomerular filtration and kidney plasma flow
Mannitol can prevent kidney damageduring acute kidney injury
Mannitol is also used toreduces intracranial pressure and cerebral deem resulting from head trauma
for mannitol to be effective there must be enoughblood flow to the kidney and glomerular filtration must still remain to enable the drug to reach the kidney tubules
contraindications for Mannitolsevere kidney disease, pulmonary edema, and active intracranial bleedin
ADE of mannitolconvulsions, thrombophlebitis, and pulmonary congestionheadaches, chest pain, tachycardia, blurred vision, chills, and fever
potassium sparing diuretics (aldosterone inhibiting diuretics)block aldosterone and causes sodium and water to be excreted and potassium retained
Potassium sparing diuretics act in thecollecting ducts and distal convoluted tubules where they interfere with sodium potassium exchange
potassium sparing are often used asadjuncts with thiazide treatment
spironolactone and triamterene (potassium sparing diuretics) used totreat hyperaldosteronism and hypertension and to reverse potassium loss caused by potassium wasting diuretics
contraindications for potassium sparing diureticshyperkalemia, and severe kidney failure or anuria
ADE of potassium sparing diureticsgynecomastia, amenorrhea, irregular menses, and postmenopausal bleeding
thiazide and thiazide like diuretics site of actiondistal convoluted tubule, where they inhibit the resorption of sodium, potassium, and chloride – resulting in osmotic water loss
as kidney function decreases the efficacy of thiazidesdiminishes because delivery of the drug to the site of activity is impaired
thiazides not to be used ifcreatinine clearance is less than 30 to 50 mL/min (normal is 125mL/min)
thiazide are used intreatment of edema of various origins, idiopathic hypercalciuria, and diabetes insipidus, and hypertension
major ADE for thiazide iselectrolyte and metabolic disturbances

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