Class IV antiarrhythmics (calcium channel blockers) — Flashcards

Flashcard 1: Calcium Channel Blockers (CCBs) Diltiazem has some vaso-_____ activity

Answer: dilatory

Flashcard 2: Class I antiarrhythmics exert their actions by blocking _____ channels

Answer: Na+

Flashcard 3: What calcium channel blocker may be combined with nitrates, producing similar effects to β-blockers?

Answer: Verapamil

Flashcard 4: Which Ca2+ channel blocker has the most potent effects on cardiac muscle? _____

Answer: Verapamil

Flashcard 5: Calcium Channel Blockers (CCBs) Which Ca2+ channel blockers (2) have the most potent effects on vascular smooth muscle? _____

Answer: Amlodipine, Nifedipine

Flashcard 6: Verapamil and diltiazem are both examples of _____ Ca2+ channel blockers

Answer: non-dihydropyridine

Flashcard 7: vardenafil

Answer: PDE5 inhibitor

Extra: erectile dysfunctionpatients taking nitrates (lethal hypotension)inhbit phosphodiesterase 5, resulting in increased cGMP and smooth muscle relaxation in corpus cavernosumheadache, flushing, impaired blue-green color vision, hypotension, dyspepsia

Flashcard 8: sildenafil

Answer: PDE5 inhibitor

Extra: erectile dysfunctionpatients taking nitrates (lethal hypotension)inhbit phosphodiesterase 5, resulting in increased cGMP and smooth muscle relaxation in corpus cavernosumheadache, flushing, impaired blue-green color vision, hypotension, dyspepsia

Flashcard 9: What is the effect of high-dose Aspirin (salicylates) on oxidative phosphorylation?

Answer: Uncouples oxidative phosphorylation (increases permeability of the inner mitochondrial membrane)

Extra: Aspirin (salicylates) in high doses uncouples oxidative phosphorylation, leading to a decreased ATP production and increased heat production (fever). It also contributes to the metabolic acidosis seen in salicylate toxicity.

Flashcard 10: Mechanism of action of Ouabain?

Answer: Inhibits Na+/K+-ATPase by binding to the K+ binding site

Extra: Ouabain is a cardiac glycoside (similar to digoxin) that binds to the extracellular side of the Na+/K+-ATPase pump, competing with Potassium (K+). This leads to increased intracellular Na+, which in turn decreases the activity of the Na+/Ca2+ exchanger, resulting in increased intracellular Ca2+ and positive inotropy.