Digoxin Toxicity
May 29, 2008
Digoxin toxicity has always been a major problem, due to the narrow range separating medically-effective digoxin levels from toxic levels of the drug. Now, with the recent mislabeling and mispackaging of digoxin that led to people being given digoxin doses equivalent to twice their prescribed dosage, and the subsequent recall, many people are concerned with digoxin toxicity.
Diagnosing Digoxin Toxicity
Digoxin toxicity is responsible for many nonspecific symptoms, making it very difficult to diagnose.These symptoms include:
· Visual changes, such as halos, unfocused vision, changes in color vision, even hallucinations
· Lethargy or drowsiness
· Confusion or euphoria
· Headaches
· Nausea and vomiting
· Diarrhea
· Abdominal pain
Toxicity can take minutes or hours to become evident. Acute toxicity generally manifests itself with nausea, vomiting, and lethargy, while chronic toxicity is usually signaled by visual changes, but can be very difficult to diagnose. The only way to actually diagnose digoxin toxicity is with blood tests.
Influences on Toxicity Levels
Unfortunately, digoxin can often be made more toxic by other factors in your body. This includes:
· High or low mineral levels, including elevated potassium or calcium levels, or depressed potassium or magnesium levels
· Kidney disease
· Hypothyroidism
· Low blood oxygen levels
· High blood pH
· Other medications, including:
o Beta-blockers, calcium channel blockers, and other medications that affect your mineral levels
o Diuretics
o Antibiotics such as tetracycline that inactivate bacteria that can inactivate digoxin
These risk factors can dramatically affect the level of digoxin in your bloodstream, making it more likely that you will suffer digoxin toxicity with a lower dose.
Digoxin Resilience
In addition to digoxin’s narrow therapeutic range and its susceptibility to other factors in your body, another element that makes digoxin toxicity so dangerous is that digoxin tends to stay in your body for a long period of time after your toxic exposure.
Digoxin has what is known as a relatively long biological half-life. Biological half-life is the amount of time it takes for a drug or other substance in your body to lose half of its effect. This depends on the volume of blood in your body and the ability of your kidneys to filter the drug from your bloodstream. A normal half-life for digoxin ranges from 24-36 hours in a person with healthy kidneys.
However, because you were prescribed digoxin for regulating a dangerous heart condition, you cannot simply stop the medication once you realize you may have received twice your dosage, or you will experience a period in which you are exposed to the even greater danger of your heart condition. Instead, you will have to take your digoxin at the lower dosage and allow your body to stabilize the level of the drug in your blood, which usually takes about 4.7 times the biological half-life, or a week or more.
In addition, because chronic digoxin toxicity is difficult to diagnose, and occurs frequently without being detected, you may have been suffering from digoxin toxicity for a long time, but only detected it as a result of the Actavis error. In this case, you will need to be evaluated for chronic toxicity, and it may take much longer for your digoxin levels to regulate.
Click Here to speak to an attorney about this recall!
Click Here to speak to an attorney about this recall!
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