Digoxin Flashcards
2 therapeutic uses of digoxin are…
treatment of CHF & Atrial arrhythmia
3 MOA of digoxin at therapeutic dose….
Increase diastolic time hence decrease HR (-ve chronotropic)
Increase strength of contraction (+ve ionotropic)
Increase renal blood flow
4 areas invloved in digoxin toxicity….
Cardiac
GI
Visual
CNS
2 pathophysiology of digoxin…
Increase vagus (bradychardia) stimulation
Inhibition of NA/K ATP pump
Clinical presentation of digoxin toxicity…
Cardiac: arrhythmia
GI: Nausea, vomitting, diarrhea, colic
Visual: Green yellow vision
CNS: Headache, delerium, disorientation, drowsiness
Cause of death in digoxin toxicity is…
Arrhythmia and cardiac arrest
4 investigations for digoxin toxicity…
-ECG with continuos monitoring
-Electrolyte levels: Hypercalcemia, hypomagnesemia, hyperkalemia in acute toxicity, hypokalemia in chronic toxicity
- renal function test
-serum levels of digoxin (therapeutic<2ng/ml, poor prgnosis>15ng/ml)
Which electrolyte disturbance exacerbates the toxicity?
Hypercalcemia
Hypokalemia
Hypomagnesemia
4 treatment methods of digoxin toxicity…
- prevent further exposure
- supportive
- GI decontamination
- physiological antidote
What is the supportive treatment of digoxin toxicity?
-Treat arrhythmia with Lidocane, phenytoin and atropine
- Treat electroylte imbalances
>Hyperkalemia: insulin with 5% glucose to prevent hypoglycemia
>Hypokalemia: KC1
>Hypercalcemia: Non Ca EDTA
How do you do GI decontamination in digoxin toxicity…
Gastric lavage
Local antidote: Charcoal and cholestyramine
Physiological antidote of digoxin and MOA
Digibind: binds to glycoside ( the components of digitalis which include digoxin, digitoxin, digitonin, digitalin) and the compound formed is easily excreted in urine
4 indication times of digibind are…
-Presence of arrhythmia
-Heart block (even if 1st degree)
-Serum digoxin levels more than 10ng/ml or ingestion of more than 10mg in adults or serum levels more than 5ng/ml or ingestion more than 4mg in children
-severe hyperkalemia
