Cardiac Agents

Question 1

digoxin action

Answer 1

• inhibits sodium-potassium pump → increases intracellular calcium during depolarization
• positive inotropic effect (increases contractility)
• negative chronotropic and dromotropic effect (decreases HR and AV node conduction)
• increases CO and stroke volume
• decreases fluid retention, increases fluid excretion

Question 2

digoxin

Answer 2

• trade: Lanoxin
• a cardiac glycoside
• derived from foxglove plant

Question 3

digoxin use (3)

Answer 3

• CHF
• atrial flutter/fibrillation
• paroxysmal atrial tachycardia

Question 4

you can also use _____ and _____ if digoxin is not effective

Answer 4

calcium channel blocker Verapamil (Calan) and Warfarin (Coumadin)

Question 5

digoxin PO/IV dose

Answer 5

0.5-1 mg initial dose for digitalization (divided into 2) + 0.125-0.5 mg/day for maintenance

Question 6

digoxin half-life

Answer 6

30-40 hours

Question 7

digoxin + antacids interaction

Answer 7

decreased serum digoxin levels due to decreased absorption

Question 8

digoxin + thiazides and loop diuretics interaction

Answer 8

increased risk for toxicity - due to hypokalemia

Question 9

digoxin + Quinidine, Verapamil, Flecainide interaction

Answer 9

increased serum digoxin levels - compete for drug receptor site and enzyme pathways

Question 10

_____, _____, and _____ can increase risk for digitalis toxicity

Answer 10

hypokalemia, hypomagnesemia, and hypercalcemia

Question 11

digoxin + ginseng interaction

Answer 11

falsely elevates digoxin level

Question 12

digoxin + St. John’s wort interaction

Answer 12

decreases absorption and serum level of digoxin

Question 13

digoxin + hawthorn interaction

Answer 13

increases effects of digitalis

Question 14

digoxin + aloe interaction

Answer 14

increased potassium loss

Question 15

digoxin + Ma-Huang interaction

Answer 15

increases risk for digitalis toxicity

Question 16

digoxin + licorice interaction

Answer 16

potentiates effect of digoxin

Question 17

therapeutic serum digoxin level

Answer 17

0.5-2.0 mg/mL

Question 18

digoxin toxicity symptoms (7)

Answer 18

• bradycardia
• premature ventricular contractions (PVCs)
• cardiac dysrhythmias - heart blocks, tachycardia
• headache
• blurred vision
• visual illusions - white, green, yellow halos around objects
• confusion, delirium

Question 19

carvedilol

Answer 19

• trade: Coreg
• a beta blocker
• antioxidant protectant

Question 20

carvedilol use

Answer 20

slows progression of CHF

Question 21

carvedilol action

Answer 21

• blocks beta 1 and 2, and alpha 1 receptors
• antioxidant protects against free radicals causing damage to nucleic acids, proteins, and lipids, which are linked to cancer and atherosclerosis

Question 22

what type of med is used as the primary line of therapy for majority of patients with heart failure and pulmonary congestion?

Answer 22

diuretics!

Question 23

thiazides action

Answer 23

inhibits active exchange of chlorine and sodium in the cortical diluting segment of the ascending loop of Henle/distal convoluted tubule

Question 24

thiazides use

Answer 24

treatment of CHF

Question 25

hydrochlorothiazide

Answer 25

- trade: HCTZ | - a thiazide diuretic

Question 26

loop diuretics action

Answer 26

inhibits exchange of chlorine, sodium, and potassium in the thick segment of the ascending loop of Henle

Question 27

loop diuretics use

Answer 27

drug most commonly given for acute exacerbation of CHF - fastest, most effective

Question 28

furosemide

Answer 28

- trade: Lasix | - a loop diuretic

Question 29

potassium-sparing diuretics action

Answer 29

- blocks production of aldosterone; promotes sodium and water excretion in distal convoluted and collecting tubules - cardioprotective effect - promotes cardiac remodeling

Question 30

potassium-sparing diuretics use

Answer 30

treatment of CHF

Question 31

spironolactone

Answer 31

- trade: Aldactone | - a K-sparing diuretic

Question 32

osmotic diuretics action

Answer 32

pulls large amounts of fluid from cells into blood/urine via osmotic effect

Question 33

osmotic diuretics uses (2)

Answer 33

- patients experiencing increased intracranial pressure or intraocular pressure - prevention of kidney failure in patients receiving Cisplatin chemotherapy - promotes blood flow to kidneys

Question 34

mannitol side effects (3)

Answer 34

- fluid/electrolyte imbalance - pulmonary edema - nausea/vomiting

Question 35

mannitol contraindications (2)

Answer 35

- CHF | - renal failure

Question 36

mannitol

Answer 36

- trade: Osmitrol - an osmotic diuretic - a sugar - uses osmotic pull of sugar to pull fluid into urine

Question 37

carbonic anhydrase inhibitors action

Answer 37

inhibits action of carbonic anhydrase (enzyme that helps maintain balance of hydrogen ion and bicarbonate) → sodium, potassium, bicarbonate excretion in proximal renal tubule; decreases acid secretion

Question 38

carbonic anhydrase inhibitors uses (3)

Answer 38

- decrease intraocular pressure in open-angle/chronic glaucoma - before eye surgery - also used to alkalinize urine - ex. in rhabdomyolysis

Question 39

carbonic anhydrase inhibitors side effects (5)

Answer 39

- fluid/electrolyte imbalance - metabolic acidosis - nausea/vomiting, anorexia - confusion - orthostatic hypotension

Question 40

carbonic anhydrase inhibitors adverse reactions (3)

Answer 40

- hemolytic anemia - renal calculi - crystalluria

Question 41

acetazolamide

Answer 41

- trade: Diamox | - a carbonic anhydrase inhibitor