Pharmacology Flashcards
What is the mechanism of mannitol?
Osmotic diuretic
Increase tubular fluid osmolarity, producing increased urine flow
What is the clinical use of mannitol?
Shock
Drug overdose
Treat increased intracranial/intraocular pressure
Toxicity of mannitol
Pulmonary edema
Dehydration
Contraindicated in anuria, CHF
Mechanism of acetazolamide
Carbonic anhydrase inhibitor
Causes self-limited NaHCO3 diuresis and reduction in total-body HCO3- stores
Clinical use of acetazolamide
Glaucoma
Urinary alkalinization
Metabolic alkalosis
Altitude sickness
Toxicity of acetazolamide
Hyperchloremic metabolics acidosis
Neuropathy
NH3 toxicity
Sulfa allergy
Mechanism of furosemide
Sulfonamide loop diuretic
Inhibits cotransport system (Na+, K+, 2 Cl-) of thick ascending limb of loop of Henle
Abolishes hyperotnicity of medulla, preventing concentration of urine
Stimulates PGE release (vasodilatory effect on afferent arteriole); inhibited by NSAIDs
Increase Ca2+ excretion
Clinical use of furosemide
Edematous states
- CHF
- Cirrhosis
- Nephrotic syndrome
- Pulmonary edem
HTN
Hypercalcemia
Toxicity of furosemide
Ototoxicity
Hypokalemia
Dehydration
Allergy
Nephritis
Gout
Mechanism of ethacrynic acid
Phenoxyacetic acid derivative (Not a sulfonamide)
Essentially same action as furosemide
Clinical use of ethacrynic acid
Diuresis in patients allergic to sulfa drugs
Toxicity of ethacrynic acid
Similar to furosemide
Can cause hyperuricemia
Never use to treat gout
Mechanism of hydrochlorothiazide
Thiazide diuretic
Inhibits NaCl reabsorption in early distal tubule, reducing concentrating capacity of the nephron
Decreases Ca2+ excretion
Clinical use of hydrochlorothiazide
HTN
CHF
Idiopathic hypercalciuria
Nephrogenic diabetes insipidus
Toxicity of hydrochlorothiazide
Hypokalemic metabolic alkalosis
Hyponatremia
Hyperglycemia
Hyperlipidemia
Hyperuricemia
Hypercalcemia
Sulfa allergy
What are the K+ sparing diuretics?
Spironolactone
Triamterene
Amiloride
Eplerenone
Mechanism of spironolactone
Competitive aldosterone receptor antagonist in the cortical collecting tubule
Clinical use of K+ sparing diuretics
Hyperaldosteronism
K+ depletion
CHF
Toxicity of K+ sparing diuretics
Hyperkalemia (can lead to arrhythmias)
Endocrine effects with aldosterone antagonists
How do diuretics affect urien NaCl?
Increases urine NaCl
serum NaCl may decrease as a result
How do diuretics affect urine K+?
Increases K+
Serum K+ may decrease as a result
Which diuretics lower blood pH?
Carbonic anhydrase
Which diuretics increase blood pH?
Loop diuretics and thiazides
How do loop diuretics affect urine Ca+?
Increase
Decreased paracellular Ca+ reabsorption → hypocalcemia
How do thiazides affect urine Ca+?
Decrease
Enhanced paracellular Ca2+ reabsorption in proximal tubules and loop of Henle
Name 3 ACE inhibitors
Captopril
Enalapril
Lisinopril
Mechanism of ACE inhibitors
Inhibit angiotensin-converting enzyme, reducing levels of angiotensin II and preventing inactivation of bradykinin, a potent vasodilator
Renin release is increased due to loss of feedback inhibition
Clinical use of ACE inhibitors
HTN
CHF
Diabetic renal disease
Prevent unfavorable heart remodeling as a result of chronic HTN
Toxicity of ACE inhibitors
Cough
Angioedema
Taste changes
hypOtension
Pregnancy problems
Rash
Increased renin
Lower angiotensin II
Hyperkalemia
Avoid bilateral renal artery stenosis because ACE inhibitors significantly decrease GFR by preventing constriction of efferent arterioles
Increase in serum creatinine `
