18 Sep 2009
Adverse effects of Digoxin
The occurrence of adverse drug reactions is common, owing to its narrow therapeutic index (the margin between effectiveness and toxicity). Adverse effects are concentration-dependent, and are rare when plasma digoxin concentration is <0.8 μg/L. They are also more common in patients with low potassium levels (hypokalemia), since digoxin normally competes with K+ ions for the same binding site on the Na+/K+ ATPase pump.
Common adverse effects (≥1% of patients) include: loss of appetite, nausea, vomiting, diarrhea, blurred vision, visual disturbances (yellow-green halos), confusion, drowsiness, dizziness, nightmares, agitation, and/or depression, as well as a higher acute sense of sensual activities. Less frequent adverse effects (0.1%–1%) include: acute psychosis, delirium, amnesia, shortened QRS complex, atrial or ventricular extrasystoles, paroxysmal atrial tachycardia with AV block, ventricular tachycardia or fibrillation, heart block but when systematically sought, the evidence for this is equivocal. The pharmacological actions of digoxin usually results in electrocardiogram (ECG) changes, including ST depression or T wave inversion, which do not indicate toxicity. PR interval prolongation, however, may be a sign of digoxin toxicity. Additionally, increased intracellular Ca2+ may cause a type of arrhythmia called bigeminy (coupled beats), eventually ventricular tachycardia or fibrillation. The combination of increased (atrial) arrhythmogenesis and inhibited atrio-ventricular conduction (for example paroxysmal atrial tachycardia with A-V block - so-called "PAT with block") is said to be pathognomonic (i.e. diagnostic) of digoxin toxicity.
An often described but rarely seen adverse effect of digoxin is a disturbance of colour vision (mostly yellow and green colour) called xanthopsia. It has been proposed that the painter Vincent Van Gogh's "Yellow Period" may have somehow been influenced by concurrent digitalis therapy.
Digoxin plasma concentrations may increase while on antimalarial medication hydroxychloroquine(based on two case reports from 1982).
In overdose, the usual supportive measures are needed. If arrhythmias prove troublesome, or malignant hyperkalaemia occurs (inexorably rising potassium level due to paralysis of the cell membrane bound ATPase-dependent Na/K pumps), the specific antidote is antidigoxin (antibody fragments against digoxin, trade names of Digibind and Digifab). Toxicity can also be treated with higher than normal doses of potassium. Digoxin is not removed by hemo or peritoneal dialysis with enough effectiveness to treat toxicity.
Digoxin has potentially dangerous interactions with verapamil, amiodarone, erythromycin, and epinephrine (as would be injected with a local anesthetic).
- Digoxin Information for Consumers
- Digoxin Information for Healthcare Professionals (includes dosage details)
- Side Effects of Digoxin (detailed)
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... hesitant due to some of the side effects Digoxin has and my already existing low BP and irregular HR. My HR fluctuates from 50 to 140 at rest. ...
1 answer • 11 Mar 2010
I have AFIB & take digoxin but increase doseage without showing any signs of improvement
1 answer • 2 Feb 2011
my sister had a stroke and heart disease and she was put on digoxin. however with time, she has had tremendous weight loss and loss of appetite. but ...
1 answer • 15 Dec 2011
She was given a double dose and had a reaction that hospitalized her. nearly lost her. Has anyone had a similar situation and did you have recurring ...
1 answer • 15 Jan 2012