From the FDA Drug Label
In healthy volunteers with normal renal function, digoxin has a half-life of 1.5 to 2.0 days. The half- life in anuric patients is prolonged to 3. 5 to 5 days.
The half-life of digitoxin is not directly mentioned in the provided drug labels. The information provided is about digoxin, not digitoxin. Digitoxin and digoxin are two different drugs, although they are both cardiac glycosides. Therefore, no conclusion can be drawn about the half-life of digitoxin from the provided information. The FDA drug label does not answer the question.
From the Research
Half-Life of Digitoxin
The half-life of digitoxin is reported to be around 5 to 6 days in patients receiving usual doses, irrespective of renal function 1. This is consistent with another study that found the half-life of digitoxin to be approximately 5 days in patients with normal renal function 2.
Factors Affecting Half-Life
- The half-life of digitoxin is not significantly affected by renal function, as it is mainly eliminated via the liver and metabolized in the body 1.
- Hepatic cirrhosis does not seem to significantly affect the half-life of digitoxin, with studies showing similar half-lives in cirrhotic patients and normal subjects 2.
- The half-life of digitoxin can vary between individuals, with one study reporting a mean half-life of 8 days in healthy volunteers 3.
Comparison with Digoxin
- Digitoxin has a longer half-life compared to digoxin, which has a half-life of around 26 to 45 hours in healthy individuals 4.
- The half-life of digoxin is more affected by renal function, with impaired kidney function leading to a prolonged half-life 1, 4.
Clinical Implications
- The longer half-life of digitoxin may result in a lower incidence of toxic side effects compared to digoxin, due to a more stable pharmacokinetic profile 5.
- The slow accumulation of digitoxin may require a loading dose to achieve therapeutic levels quickly, with a suggested loading dose of 12 times the maintenance dose 3.