What is digoxin metabolized by?
Digoxin
| Clinical data | |
|---|---|
| Protein binding | 25% |
| Metabolism | Liver (16%) |
| Elimination half-life | 36 to 48 hours (normal kidney function) 3.5 to 5 days (impaired kidney function) |
| Excretion | Kidney |
Where is Digitoxin metabolized?
Digitoxin undergoes enterohepatic circulation. It is metabolized in part by CYP3A4; metabolites include digitoxigenin, digoxin (>2%), and conjugate esters. In healthy people, 60% are eliminated via the kidneys and 40% via the faeces. In people with impaired kidney function, elimination via the faeces is increased.
How is digitalis metabolized?
The digitalis glycosides, digoxin and digitoxin, have been examined in the light of new information regarding absorption, excretion, and metabolism. Digitoxin is completely absorbed, extensively recycled in the intestine, protein-bound, metabolized, and excreted largely in the urine as metabolites.
Why is digoxin no longer used?
The use of digoxin is limited because the drug has a narrow therapeutic index and requires close monitoring. Digoxin can cause many adverse events, is involved in multiple drug interactions, and can result in toxicity. Despite its limitations, however, digoxin has a place in therapy.
Is digoxin metabolised?
Serum digoxin concentrations are not significantly altered by large changes in fat tissue weight, so that its distribution space correlates best with lean (i.e., ideal) body weight, not total body weight. Metabolism: Only a small percentage (16%) of a dose of digoxin is metabolized.
Is digoxin metabolized by the liver?
Digoxin is minimally metabolized in the liver and does not materially affect the activity of cytochrome P450 enzymes.
What is Digitoxin used for?
Digoxin is used to treat heart failure and abnormal heart rhythms (arrhythmias). It helps the heart work better and it helps control your heart rate.
How is Digitoxin made?
It is extracted from the leaves of a plant called digitalis lanata. Digoxin increases the force of contraction of the muscle of the heart by inhibiting the activity of an enzyme (ATPase) that controls movement of calcium, sodium, and potassium into heart muscle. Calcium controls the force of contraction.
What is the half life of Digitoxin?
Mean digitoxin half-life was 25.2 days. This is significantly more than reported in other studies on younger patients. The symptoms of digitoxin intoxication disappeared on discontinuation of medication. The slow elimination of digitoxin may be related to reduced serum albumin concentration.
Can digoxin convert AFIB?
Conversion occurred in 9/19 patients on digoxin and in 8/20 on placebo (ns). The mean time to conversion tended to be shorter only for digoxin. Two late conversions on placebo were observed within 24 h. Heart rate during atrial fibrillation decreased after 30 min for converters and non-converters (P<005).
What enzyme metabolizes digoxin?
It is primarily metabolized through the CYP2C19 enzyme, a member of the P450 mixed-function oxidase group, although a minor pathway of metabolism is through CYP3A4, another P450 enzyme. Digoxin is primarily metabolized outside the P450 system, but a minor pathway of metabolism is by CYP3A4.
What is the difference between digoxin and digitalis?
Digoxin also slows electrical conduction between the atria and the ventricles of the heart and is useful in treating abnormally rapid atrial rhythms. Digitalis is a cardiac glycoside used to treat certain heart conditions such as congestive heart failure (CHF) and heart rhythm problems (atrial arrhythmias).
Which is better for you digoxin or digitoxin?
Digitoxin is a cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting.
Which is a cardioactive metabolite of digitoxin?
Digitoxin is extensively metabolized, presumably in the liver, to the cardioactive metabolites digoxin (about 10% of a dose), dihydrodigitoxin, digitoxigenin-bisdigitoxoside, digitoxigenin-monodigitoxoside, and digitoxigenin. Digitoxigenin is subsequently epimerized and/or conjugated to form cardioinactive compounds.
How long do the effects of digitoxin last?
After oral administration of digitoxin, the onset of action occurs in 30 minutes to 2 hours and peaks in 4-12 hours. Therapeutic effects may persist 2-3 weeks after the drug is discontinued in digitalized patients.
How does digitoxin work to treat heart failure?
Digitoxin lacks the strength of evidence that digoxin has in the management of heart failure. Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin).