Drugs

Question 1

Digoxin mechanism of action.

Answer 1

Direct inhibition of Na/K ATPase which leads to indirect inhibition of Na/Ca exchanger. This increases intracellular levels of Ca and leads to positive inotropy. Also stimulates vagus nerve to decrease HR.

Question 2

What is digoxin used clinically for?

Answer 2

HF (increased contractility) and supraventricular arrhytmias (decrease conduction at AV node)

Question 3

What are side effects caused by digoxin?

Answer 3

Arrhythmias, GI upset, blurry yellow vision, AV block, hyperkalemia

Question 4

What factors predispose to digoxin toxicity?

Answer 4

Renal failure, hypokalemia, verapamil, amiodarone, quinidine

Question 5

How do you treat digoxin toxicity?

Answer 5

Slowly normalize K, cardiac pacer, anti-digoxin Fab fragments, Mg

Question 6

Aspirin mechanism of action.

Answer 6

Irreversibly inhibits coclooxygenase (COX-1 and COX-2) by covalent acetylation. This reduces production of TXA2 and prostaglandins.

Question 7

What are the affects of aspirin on bleeding time, PT, and PTT.

Answer 7

Increased bleeding time, others are normal

Question 8

What are the clinical uses of aspirin?

Answer 8

Antipyretic, analgesic, anti-inflammatory, antiplatelet

Question 9

What are the side effects that aspirin can cause?

Answer 9

GI upset, tinnitus, renal disease, hemorrhagic stroke, allergic reactions. Reye syndrome in children with viral infection.

Question 10

What occurs during an aspirin overdose?

Answer 10

Hyperventilation and respiratory alkalosis. Transitions to mixed metabolic acidosis-respiratory alkalosis.