Kidney regulation affects
Fluid volume
Electrolytes
Acid base balance
Kidney secretions
Renin
Erthropoietin
Calcitrol
Renin
For blood pressure regulation
Erythropoietin
Stimulate RBC production
Calcitriol
Active vitamin D for bone homeostasis
Urinary system consists of how many kidneys
2
Urinary system consists of how many ureters
2
Urinary system consists of how many bladders
1
Urinary system consists of how many urethras
1
Nephron
Functional units of the kidney
Blood that enters the nephrons is filtered through
The glomerulus
Water and small molecules that enter the nephron pass into
The proximal tubule
What materials are reabsorbed in the urinary system
Glucose
AAs
Na
Cl
Ca
Bicarbonate
What materils are secreted into the filtrate
K
PO4
H+
NH4
Acidic drugs
Renal failure
Decrease in kidney's ability to function
Drugs can accumulate to high lvls
What changes must be done to meds for those with renal failure
Doses are to be adjusted
Administering an average dose to those with renal failure can cause
Fatality
How can renal failure be diagnosed?
Urinalysis
Serum creatinine
Diagnostic imaging
Renal biopsy
Glomerular filtration rate (GFR)
Best marker for estimating renal function
Measure volume of filtrate passing through Bowman's capsule per minute
Acute renal failure
requires immediate treatment
Accumulation of wastes can be fatal
Most common cause is hypoperfusion
Acute renal failure can be caused by
Heart failure
Dysrhythmias
Hemorrhage
Dehydration
Chronic renal failure
Occurs over months or years
Usually includes history of diabetes mellitus or hypertension
Nephrotoxic drugs can be a cause of acute or chronic renal failure
Anemia pathogenesis
Kidneys unable to synth enough erythropoietin for RBC production
Hyperkalemia
Kidneys are unable to adequately excrete K
Hyperphosphatemia
Kidneys are unable to adequately ecrete PO4
Hypervolemia
Kidneys are unable to excrete sufficient Na and H2O = water retention
Hypocalcemia
Hyperphosphatemoa = Ca loss
Metabolic acidosis
Kidneys unable to excrete metabolic acids well
Diuretics
Increase rate of urine flow
Diuretics are used to treat
Hypertension, heart failure, kidney failure
Liver failure/cirrhosis, pulmonary edema
Carbonic anhydrase inhibitors
Inhibit reabsorption of bicarbonate ions in proximal tubule
Carbonic anhydrase adverse effects
Allergies(for those allergic to sulfa)
Fluid and electrolyte imbalances
Carbonic anhydrase primary use
Decrease intraocular fluid pressure in patients with open angle glaucoma
Carbonic anhydrase inhibitor mechanism of action
Inhibit carbonic acid formation
Osmotic diuretics
Act on proximal tubule & Henle loop
Creates osmotic force that pulls water into nephron= Increases electrolyte excretion
Osmotic diuretic primary use
Reduce intracranial pressure due to cerebral edema
Osmotic diuretic mechanism of action
Inhibits carbonic anhydrase
Loop diuretics
Act on ascending loop of Henle
Block Na, Cl, H2O reabsorption
Increased K excretion
Thiazide diuretics
Act on early distal tubule
Block Na, Cl, H2O reabsorption
Increased K excretion
Potassium sparring diuretics
Act on late distal tubule and collecting ducts
Block NA reabsorption
Reduce K secretion
Adverse effects of diuretic therapy
Fluid & electrolyte disturbances
Dehydration
Orthostatic hypotension
K and Na imbalances
Loop diuretics mechanism of action
Block Na and Cl reabsorptionin loop of Henle
Primary use of loop diuretics
Reduce edema assoc w heart, hepatic cirrhosis, renal failure
Furosemide and torsemide also approved for hypertension
Loop type diuretic prototype drug
Furosemide (Lasix)
Furosemide uses
Acute heart failure treatment (has ability to remove large amounts of excess fluid from patient)
Beneficial when cardiac output and renal flow are severly diminished
Furosemide (Lasix) when given IV, diuresis begins within
5 minutes, giving patient quick symptom relief
Furosemide (Lasix) action
Preventing reabsorption of Na and Cl in loop of Henle region of the nephron
Furosemide (Lasix) administration alerts
Check patient's serum potassium lvls before administering the drug
If potassium lvls are below normal, contact doctor before administering
Older adults need less of a dose
Furosemide (Lasix) administration alerts in neonates and premature infants
Handle drug with caution due to the drug's prolonged half life
Furosemide (Lasix) adverse effects
Potential electrolyte imbalances
Hypokalemia
Fluid loss/ dehydration and hypotension (MONITOR)
Hypovolemia= orthostatic hypotension and syncope
Ototoxicity= hearing deficit
Furosemide (Lasix) black box warnings
If given in excessive amounts, may lead to profound diuresis with water and electrolyte depletion
Furosemide (Lasix) contraindications
Hypersensitivity to furosemides/ sulfonamides,
anuria
hepatic coma
severe fluid/electrolyte depletion
Furosemide (Lasix) overdose treatment
Overdose= Hypotension and severe fluid/electrolyte loss
Supportive treatment
Replacement of fluids and electrolytes
Possible administration of a vasopressor
Thiazide diuretics mechanism of action
Block Na+ reabsorption and increase K+ & H2O excretion
Thiazide diuretic primary use
Treat mild to moderate hypertension
Also indicated to reduce edema assoc w heart, hepatic and renal failure
Thiazide diuretics are not effective for
Patients with severe renal failure
Thiazide diuretic prototype drug
Hydrochlorothiazide (Microzide)
Hydrochlorothiazide (Microzide) action
Decreases Na+ reabsorptionin kidney tubule
More Na+, and water is sent to the urine= blood volume decreases and blood pressure falls
Using Hydrochlorothiazide (Microzide), the volume of urine produced is directly proportional to
The amount of sodium reabsorption blocked by the diuretic
Hydrochlorothiazide (Microzide) administration alers
Administer early in day to prevent nocturia
Pregnancy category B
Hydrochlorothiazide (Microzide) adverse effects
Potential electrolyte imbalance due to excessive K+ and Na+
Gout attacks
Hyperuricemia
Cardiac conduction abnormalities
Hydrochlorothiazide (Microzide) contraindications
Anuria
Prior hypersensitivity to thiazides and sulfonamides
Pre-eclampsia
Pregnancy induced HTN
Hydrochlorothiazide (Microzide)- antihypertensive interactions
Additive/synergistic effects on blood pressure
Hydrochlorothiazide (Microzide)- anticoagulants, sulfonylureas, and antidiabetic drugs (ex. insulin) interactions
Decrease effectiveness
Hydrochlorothiazide (Microzide)- cholestyramine and colestipol interactions
Decrease hydrochlorothiazide absorption and effectiveness
Hydrochlorothiazide (Microzide)- NSAIDs interactions
Increased risk of renal toxicity
Hydrochlorothiazide (Microzide)- Corticosterioids and amphotericin B interactions
Increase K+ loss when given with Hydrochlorothiazide (Microzide)
Hydrochlorothiazide (Microzide)-Lithium interactions
Lithium excretion decreases= Li toxicity
Hydrochlorothiazide (Microzide) overdose treatment
Overdose manifests as electrolyte depletion
Treated with infusions of fluids containing electrolytes to prevent dehydration and hypotension
Advantage of potassium-sparring diuretics
Diuresis without affecting blood potassium lvls
Potassium-sparing diuretic mechanism of action
Either by:
Blocking Na+ or by blocking aldosterone
Aldosterone
Hormone that controls renal reabsorption of sodium and potassium, causing water retention
Secreted by adrenal cortex
Potassium-sparing diuretic prototype drug
Spironolactone (Aldactone)
Spironolactone (Aldactone) uses
Treat mild hypertension in combo with other antihypertensives
Reduce edema assoc w kidney or liver disease
Slowing progrssion of heart failure
Spironolactone (Aldactone) action
Inhibits aldosterone , increasing Na+ and water excretion and body retains more K+
Spironolactone (Aldactone) administration alerts
Give with food to increase drug absorption
Do not give K+ supplements
Pregnancy category C
Spironolactone (Aldactone) adverse effects
Hyperkalemia (increased risk with K+ supplements or concurrent use with ACE inhibitors)
Gynecomastia impotence and diminished libido (men)
Menstrual irregularities, hirsutism, breast tenderness (women)
Signs/ symptoms of hyperkalemia
Muscle weakness
Fatigue
Bradycardia
Spironolactone (Aldactone) black box warnings
Causes tumors in animals in clinical studies
Spironolactone (Aldactone) contraindications
Anuria
Renal function impairment
Hyperkalemia
Pregnancy and lactation
Spironolactone (Aldactone)- ammonium chloride interaction
Acidosis
Spironolactone (Aldactone)- aspirin and other salicylates interactions
Increased half life= digoxin toxicity
Spironolactone (Aldactone)- concurrent digoxin use interactions
Decreased digoxin effects
Spironolactone (Aldactone)- potassium supplements, ACE inhibitors and angiotension receptor blockers (ARBs) interactions
Hyperkalemia
Spironolactone (Aldactone)-concurrent antihypertensive use interactions
Hypotensive effect
Spironolactone (Aldactone) overdose treatment
Supportive therapy
Agents to replace fluid and electrolyte loss for diuresis to raise blood pressure
Carbonic anhydrase inhibitors
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