CV: Cardiac glycosides

Question 1

How is digoxin toxicity treated?

Answer 1

Digoxin-specifc antibody fragments are indicated for the treatment of known or strongly suspected life-threatening digoxin toxicty associated with ventricular arrhythmias or bradyarrhythmias unresponsive to atropine sulfate and when measures beyong the withdrawal of digoxin and correction of any electrolyte abnormalities are considered necessary.

Question 2

What is digoxin most useful for?

Answer 2

Controlling ventricular response in persistent and permanent atrial fib and atrial flutter. Digoxin also has a role in heart failure.

Question 3

For the management of atrial fibrillation the maintenance dose of digoxin can usually be determined by what?

Answer 3

The ventricular rate at rest, which should not usually be allowed to fall persistently below 60 beats per minute.

Question 4

In patients with heart failure who are in sinus rhythm a loading dose is not required, and a satisfactory plasma-digoxin concentration can be achieved over what period?

Answer 4

A week

Question 5

Digoxin has a long half-;ofe and maintenance doses need to be given only once daily, what is the most important determinant of digoxin dosage?

Answer 5

Renal function

Question 6

The plasma concentration of digoxin alone cannot indicate toxicity reliably, but the likelihood of toxicity increases progressively through the range 1.5 to __ micrograms/litre.

Answer 6

It can sometimes be difficult to distinguish between toxic effects and clinical deterioration because symptoms of both are similar. The plasma concentration alone cannot indicate toxicity reliably, but the likelihood of toxicity increases progressively through the range 1.5 to 3 micrograms/litre for digoxin. Digoxin should be used with special care in the elderly, who may be particularly susceptible to digitalis toxicity.

Question 7

What electrolyte imbalance predisposes a patient to digitalis toxicity?

Answer 7

HYPOKALAEMIA