Chapter 6 - Renal Drugs Flashcards
What is a nephron
Basic functional unit of kidneys
How does a kidney maintain homeostasis
Filtration, reabsorption, secretion. Fluid balance regulation. Acid-base balance regulation. Production of hormones-erythropoietin. Blood pressure regulation.
What does a nephron consist of
Renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule
Describe the blood supply of the kidney
Renal artery enters the kidney at the hilus. Divides into smaller arteries and arterioles
What is the distal convoluted tubule
Continuation of the ascending loop of henle
What is the purpose of The distal convoluted tubule
Carrie tubular filtrate through the medulla. Empty into renal pelvis. Primary site of action of ADH and regulation of potassium an acid-base balance
Describe sodium reabsorption in the proximal convoluted tubule
Sodium in tubular filtrate attaches to carrier protein that moves it into the cytoplasm of the proximal convoluted tubule epithelial cell.
Describe sodium cotransport in the proximal convoluted tubule
Glucose and amino acids attach to the same carrier protein and follow sodium into the cell by passive transport.
Describe urine volume regulation in the kidney
Determined by amount of water contained in the tubular filtrate when it reaches the renal pelvis. Controlled by actions of ADH and aldosterone.
What gland created ADH hormone
Anterior pituitary gland
What does adh hormone do
Acts on the distal convoluted tubule and collecting ducts to promote reabsorption.
What disease do you have if you don’t have the ADH hormone
Diabetes insipitus
what does aldosterone hormone trigger
Increases reabsorption of sodium
What are the reflex components of urine control
A spinal reflex returns a motor impulses to the bladder muscles causing them to contract. Contraction gives the sensation of having to urinate
What are the three aspects of urine formation
️Glomerular filtration
Tubular reabsorption
Tubular secretion
What is erythropoiesis
Formation of erythrocytes.
What is erythropoietin
A hormone secreted by the healthy kidneys to cause the formation of erythrocytes.
What happens if the kidney is not producing erythropoietin
Animal may develop a non-regenerative anemia as a result
How do you confirm uremia
Blood tests
What can uremia do
Increase the sensitivity of some tissues to certain drugs
What blood tests do you do for uremia
Creatinine and bun (blood urea nitrogen)
What are diuretic drugs
Urine producing drugs. Used to remove excess extracellular fluid by increasing urine flow and sodium excretion and reducing hypertension
What is extracellular fluid
Edema
What are the two main reasons for diuretic use
To remove fluid from organs and to reverse high blood pressure
What are loop diuretics
Highly potent diuretics that inhibit the tubular reabsorption of sodium. They also promote the excretion of chloride, potassium and water.
What can happen to some patients on long term loop diuretic therapy
May also have to be placed on potassium supplementation
What are the dosage forms of the loop diuretics
Furosemide (lasix, disal, diuride)
What are the adverse side effects of loop diuretics
Hypokalemia
What are osmotic diuretics
Can be administered intravenously to promote diuresis by exerting high osmotic pressure in the kidney tubules and limiting tubular reabsorption
How does osmotic diuresis work
Water is drawn into the glomerular filtrate, reducing its reabsorption and increasing the excretion of water
What can osmotic diuretic drugs be used to treat
Oliguric acute renal failure and to reduce intracranial pressure
What are the dosage forms of osmotic diuretics
Mannitol 20% and Glucose
What do thiazide diuretics do
Reduce edema by inhibiting reabsorption of sodium, chloride and water. Their duration is longer than loop diuretics
What are the adverse side effects of loop diuretics
Hypokalemia if therapy is prolonged. A potassium supplement may be necessary to prevent Hypokalemia
What is a potassium sparing diuretic
Weaker diuretic and antihypertensive effects than other diuretics but they have the ability to conserve potassium.
What are potassium diuretics also called
Aldosterone antagonists.
What does an aldosterone antagonist do
Enhances the excretion of sodium and water and reduces the excretion of potassium.
What is special about edema associated with heart failure
Aldosterone might be a factor
What type of muscle is the detrusor muscle
Smooth muscle
What type of muscle is the internal urinary sphincter
Smooth muscle
What type of muscle is the external urinary spinchter
Skeletal muscle
What are the clinical uses of cholinergics
Used to help void the urinary bladder. Their action increases the tone of the detrusor muscle of the bladder and decreases bladder capacity
What is the dosage form of cholinergic agents
Bethanechol (urecholine and duvoid)
In what clinical situations would you use cholinergic agents
Weakened bladder muscle from over distension due to a urinary blockage. Spinal cord injury
Why do you use anticholinergic drugs
They block the action of acetylcholine at receptor sites in the parasympathetic nervous system.
What are anticholinergic drugs considered
Parasympatholytic because of their ability to block the passage of impulses through the parasympathetic nerves. Promotes muscle relaxation.
What is the clinical use of anticholinergic a
Used to treat urge incontinence by promoting the retention of urine in the urinary bladder.
What are the dosage forms of anticholinergic drugs
Propantheline
Buscopan
What are the Thiazide diuretics
Diuril
Hydrodiuril
What is the dosage form of potassium sparing diuretics
Aldactone
What does alpha adrenergic agonists do
Turn up the volume dial on the hold it message from the high neurologic areas. Increases internal spinchter tone
What medication Is used as an Adrenergic agonist
Phenylpropanolamine
What do adrenergic antagonists do
Relax vascular smooth muscle, enhance peripheral vasodilation and decrease blood pressure.
What is the clinical use of adrenergic antagonists
Reduce internal sphincter tone when the urethral sphincter is in hypertonus. This action is useful in treatment of urinary retention because of detrusor areflexia
What is detrusor areflexia
Functional urethral obstruction
What is prazosin used for
Effective in controlling moderate to severe hypertension which is a complicating factor in chronic renal failure
What are the dosage forms of adrenergic antagonists
Dibenzyline
Minipress
What are the adverse side effects of adrenergic antagonists
Rapid decrease in blood pressure, resulting in weakness or syncope after the first dose of prazosin. Usually self limiting.
What do beta adrenergic antagonists do
Inhibit the action of catecholamines and other sympathomimetic agents at the beta adrenergic receptor sites and therby inhibit stimulation of the sympathetic nervous system
What are the clinical uses of beta adrenergic antagonists
Include the control of mild to moderate hypertension associated with chronic renal failure
What is the dosage form of beta adrenergic antagonists
Inderal
What are the adverse side effects
Decreased Cardiac output and promotion of bronchospasm.
What is estrogen used for
Helps to increase sphincter tone
What is the dosage form of estrogen
Stillbesterol
What is the typical dosaging regime of estrogen
1 tablet sid for 5 days, then once weekly for 5 weeks than as needed
What do ace inhibitors do
Block the conversion of angiotensin 1 to angiotensin 2
Decrease aldosterone secretion.
Reduce peripheral arterial resistance
Alleviate vasoconstriction.
What is the clinical use of ace inhibitors
Treat hypertension
What are the dosage forms of ace inhibitors
Benazepril (fortekor)
Capoten
Enacard
What is a vasodilator
May be substituted for or used in combination with other medications if previous drug therapy to control hypertension fails.
What are the clinical uses of vasodilator a
Used to treat non responding hypertension. Dopamine may be used to promote diuresis in patients unresponsive to loop or osmotic diuretics.
What are the dosage forms of vasodilator a
Apresoline
Intropin
What are the dosage forms of calcium channel blockers
Cardizem
Isoptin
Amiodipine
What does the adh hormone do
Regulates fluid balance in the body
In pituitary diabetes inspitidus what happens
The hormone fails to be synthesized or excreted properly and Polyuria/polydipsia occurs.
What are the clinical uses of adh hormone
Used to treat diabetes insipidus
What is the dosage form of adh
Vasopressin
Desmopressin
What is Desmopressin
Usually given as an eye drop and a nasal spray. Can cause irritation to the eye or conjunctiva.
What is Desmopressin used for during surgery
Type 1 Von willebrand’s disease
What is a urinary acidifier
Used to produce acid urine which assists in dissolving and preventing formation of struvites uroliths. Not Routinely prescribed
What are the dosage forms of urinary acidifiers
Methionine
Ammonium chloride
What do xanthine oxidase inhibitors do
Decrease the production of uric acid. Prevent ammonium acid urate uroliths.
What type of diet is usually prescribed to prevent reoccurance of uroliths
A urine alkalizing, low protein, low purine, low oxalate diet.
What is the dosage form of xanthine oxidase inhibitors
Allopurinol
What is the dosage form of urinary alkalizer a
Potassium citrate
Sodium bicarbonate
Tiopronin tablets
What are the adverse side effects of the urinary alkalizer a
Fluid and electrolyte imbalance with the use of sodium bicarbonate
What is the adverse side effects of epo
Local or systemic allergic reaction in animals and pain occurring at injection site.
What is amitriptyline
A tricyclic antidepressant and anxiolytic drug with anticholinergic, antihistamine etc properties.
What is amtriptyline used for
Idiopathic cystitis for cats
Why do glycosaminoglycans do
Covering the transitional epithelium of the urinary tract.
What is epakitin
Chitosen based nutritional supplement made from a polysaccharide from crab and shrimp shells
What where the clinical uses of epakitin
Product information states that epakitin binds phosphorus in the intestine causing phosphorus to be eliminated through the intestinal tract.
What is azodyl
Symbiotic mix containing a patented mixture of three beneficial bacteria. It’s a nitrogen trap. Reduces Azotemia.
What are the first signs of renal insufficiency
Inappetence, pu/pd, proteinuria,
What is renal insufficiency
66% or more nephrons lost. Can no longer concentrate urine but can get rid of waste.
What is renal failure
75% or more nephrons lost
What is renal failure caused by
Accumulation of waste products (bun/creatine).
What is a specific clinical sign of kidney failure
Small lumpy kidneys
What is advanced renal failure
90% or more nephrons lost.
What are the clinical signs of advanced renal failure
Uremia, weight loss, vomiting, anorexia
Diet for renal failure
Low protein, high fats, high b vitamins, low sodium, high potassium low phosphates
What are the drug treatments for chronic renal failure
Fluids Anti GI ulcer drugs (famotidine) Antiemetics (cerenia) Potassium Anti hypertensive drugs Appetite stimulant Phosphate binders (amphojel) Erythropoetin if anemic
