Pharmacology

Question 1

What is the mechanism of mannitol?

Answer 1

Osmotic diuretic

Increase tubular fluid osmolarity, producing increased urine flow

Question 2

What is the clinical use of mannitol?

Answer 2

Shock

Drug overdose

Treat increased intracranial/intraocular pressure

Question 3

Toxicity of mannitol

Answer 3

Pulmonary edema

Dehydration

Contraindicated in anuria, CHF

Question 4

Mechanism of acetazolamide

Answer 4

Carbonic anhydrase inhibitor

Causes self-limited NaHCO₃ diuresis and reduction in total-body HCO₃- stores

Question 5

Clinical use of acetazolamide

Answer 5

Glaucoma

Urinary alkalinization

Metabolic alkalosis

Altitude sickness

Question 6

Toxicity of acetazolamide

Answer 6

Hyperchloremic metabolics acidosis

Neuropathy

NH₃ toxicity

Sulfa allergy

Question 7

Mechanism of furosemide

Answer 7

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

Question 8

Clinical use of furosemide

Answer 8

Edematous states

• CHF
• Cirrhosis
• Nephrotic syndrome
• Pulmonary edem

HTN

Hypercalcemia

Question 9

Toxicity of furosemide

Answer 9

Ototoxicity

Hypokalemia

Dehydration

Allergy

Nephritis

Gout

Question 10

Mechanism of ethacrynic acid

Answer 10

Phenoxyacetic acid derivative (Not a sulfonamide)

Essentially same action as furosemide

Question 11

Clinical use of ethacrynic acid

Answer 11

Diuresis in patients allergic to sulfa drugs

Question 12

Toxicity of ethacrynic acid

Answer 12

Similar to furosemide

Can cause hyperuricemia

Never use to treat gout

Question 13

Mechanism of hydrochlorothiazide

Answer 13

Thiazide diuretic

Inhibits NaCl reabsorption in early distal tubule, reducing concentrating capacity of the nephron

Decreases Ca²⁺ excretion

Question 14

Clinical use of hydrochlorothiazide

Answer 14

HTN

CHF

Idiopathic hypercalciuria

Nephrogenic diabetes insipidus

Question 15

Toxicity of hydrochlorothiazide

Answer 15

Hypokalemic metabolic alkalosis

Hyponatremia

Hyperglycemia

Hyperlipidemia

Hyperuricemia

Hypercalcemia

Sulfa allergy

Question 16

What are the K⁺ sparing diuretics?

Answer 16

Spironolactone

Triamterene

Amiloride

Eplerenone

Question 17

Mechanism of spironolactone

Answer 17

Competitive aldosterone receptor antagonist in the cortical collecting tubule

Question 18

Clinical use of K⁺ sparing diuretics

Answer 18

Hyperaldosteronism

K⁺ depletion

CHF

Question 19

Toxicity of K+ sparing diuretics

Answer 19

Hyperkalemia (can lead to arrhythmias)

Endocrine effects with aldosterone antagonists

Question 21

How do diuretics affect urien NaCl?

Answer 21

Increases urine NaCl

serum NaCl may decrease as a result

Question 22

How do diuretics affect urine K⁺?

Answer 22

Increases K⁺

Serum K⁺ may decrease as a result

Question 23

Which diuretics lower blood pH?

Answer 23

Carbonic anhydrase

Question 24

Which diuretics increase blood pH?

Answer 24

Loop diuretics and thiazides

Question 25

How do loop diuretics affect urine Ca⁺?

Answer 25

Increase Decreased paracellular Ca⁺ reabsorption → hypocalcemia

Question 26

How do thiazides affect urine Ca⁺?

Answer 26

Decrease Enhanced paracellular Ca²⁺ reabsorption in proximal tubules and loop of Henle

Question 27

Name 3 ACE inhibitors

Answer 27

Captopril Enalapril Lisinopril

Question 28

Mechanism of ACE inhibitors

Answer 28

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

Question 29

Clinical use of ACE inhibitors

Answer 29

HTN CHF Diabetic renal disease Prevent unfavorable heart remodeling as a result of chronic HTN

Question 30

Toxicity of ACE inhibitors

Answer 30

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 `