Cardiac Agents Flashcards
digoxin action
- 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
digoxin
- trade: Lanoxin
- a cardiac glycoside
- derived from foxglove plant
digoxin use (3)
- CHF
- atrial flutter/fibrillation
- paroxysmal atrial tachycardia
you can also use _____ and _____ if digoxin is not effective
calcium channel blocker Verapamil (Calan) and Warfarin (Coumadin)
digoxin PO/IV dose
0.5-1 mg initial dose for digitalization (divided into 2) + 0.125-0.5 mg/day for maintenance
digoxin half-life
30-40 hours
digoxin + antacids interaction
decreased serum digoxin levels due to decreased absorption
digoxin + thiazides and loop diuretics interaction
increased risk for toxicity - due to hypokalemia
digoxin + Quinidine, Verapamil, Flecainide interaction
increased serum digoxin levels - compete for drug receptor site and enzyme pathways
_____, _____, and _____ can increase risk for digitalis toxicity
hypokalemia, hypomagnesemia, and hypercalcemia
digoxin + ginseng interaction
falsely elevates digoxin level
digoxin + St. John’s wort interaction
decreases absorption and serum level of digoxin
digoxin + hawthorn interaction
increases effects of digitalis
digoxin + aloe interaction
increased potassium loss
digoxin + Ma-Huang interaction
increases risk for digitalis toxicity
digoxin + licorice interaction
potentiates effect of digoxin
therapeutic serum digoxin level
0.5-2.0 mg/mL
digoxin toxicity symptoms (7)
- bradycardia
- premature ventricular contractions (PVCs)
- cardiac dysrhythmias - heart blocks, tachycardia
- headache
- blurred vision
- visual illusions - white, green, yellow halos around objects
- confusion, delirium
carvedilol
- trade: Coreg
- a beta blocker
- antioxidant protectant
carvedilol use
slows progression of CHF
carvedilol action
- 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
what type of med is used as the primary line of therapy for majority of patients with heart failure and pulmonary congestion?
diuretics!
thiazides action
inhibits active exchange of chlorine and sodium in the cortical diluting segment of the ascending loop of Henle/distal convoluted tubule
thiazides use
treatment of CHF
hydrochlorothiazide
- trade: HCTZ
- a thiazide diuretic
loop diuretics action
inhibits exchange of chlorine, sodium, and potassium in the thick segment of the ascending loop of Henle
loop diuretics use
drug most commonly given for acute exacerbation of CHF - fastest, most effective
furosemide
- trade: Lasix
- a loop diuretic
potassium-sparing diuretics action
- blocks production of aldosterone; promotes sodium and water excretion in distal convoluted and collecting tubules
- cardioprotective effect - promotes cardiac remodeling
potassium-sparing diuretics use
treatment of CHF
spironolactone
- trade: Aldactone
- a K-sparing diuretic
osmotic diuretics action
pulls large amounts of fluid from cells into blood/urine via osmotic effect
osmotic diuretics uses (2)
- patients experiencing increased intracranial pressure or intraocular pressure
- prevention of kidney failure in patients receiving Cisplatin chemotherapy - promotes blood flow to kidneys
mannitol side effects (3)
- fluid/electrolyte imbalance
- pulmonary edema
- nausea/vomiting
mannitol contraindications (2)
- CHF
- renal failure
mannitol
- trade: Osmitrol
- an osmotic diuretic
- a sugar - uses osmotic pull of sugar to pull fluid into urine
carbonic anhydrase inhibitors action
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
carbonic anhydrase inhibitors uses (3)
- decrease intraocular pressure in open-angle/chronic glaucoma
- before eye surgery
- also used to alkalinize urine - ex. in rhabdomyolysis
carbonic anhydrase inhibitors side effects (5)
- fluid/electrolyte imbalance
- metabolic acidosis
- nausea/vomiting, anorexia
- confusion
- orthostatic hypotension
carbonic anhydrase inhibitors adverse reactions (3)
- hemolytic anemia
- renal calculi
- crystalluria
acetazolamide
- trade: Diamox
- a carbonic anhydrase inhibitor
