Serum Digoxin

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Test

To determine if the amount of digoxin in your blood is at an appropriate level or to detect potentially toxic levels

When this test is required

The test to measure digoxin is requested at the beginning of drug treatment to ensure correct dosage. Digoxin takes approximately one to two weeks to reach a steady level in the blood and in the heart. A test done at the right time will be a better indication of whether you are receiving the right amount of digoxin. Digoxin levels will then be measured at a frequency decided by your doctor to maintain the right dose, or if any changes occur in the type of tablet, the dose or other medicines taken at the same time. Changes in your health can also affect levels of digoxin and its ability to control your symptoms. Some physiological changes that may affect levels of digoxin in the blood are: kidney function thyroid problems cancer stomach or intestinal illnessDigoxin will not cure heart failure but will help to control it. Since digoxin is prescribed to treat patients with a long-term, chronic condition, it is usually monitored throughout the treatment.Timing of the digoxin blood test is important. The sample should be collected at least 6-8 hours after you last took your digoxin. Very often, the blood sample will be collected just before the next dose is to be taken. Timing of the sample collection is important because if the sample is collected too soon after the drug is taken, the results of the test could be misleading and may appear to be toxic (very high) when this is not the case. This is because digoxin needs to distribute through the body after a dose has been taken, and specimens taken within the first six hours do not give enough time for this distribution to take place.

What the Test Detects

Digoxin is a drug used to treat abnormal heart rhythms and severe heart failure. This test measures the amount of digoxin in the blood. Digoxin slows the heart rate and helps to control abnormal heart rhythms know as arrhythmias. Heart failure, including congestive heart failure (CHF) causes the heart to become less effective at circulating blood around the body. As a result, blood accumulates in the legs, hands,…Digoxin is a drug used to treat abnormal heart rhythms and severe heart failure. This test measures the amount of digoxin in the blood. Digoxin slows the heart rate and helps to control abnormal heart rhythms know as arrhythmias. Heart failure, including congestive heart failure (CHF) causes the heart to become less effective at circulating blood around the body. As a result, blood accumulates in the legs, hands, feet, lungs and liver, causing swelling, shortness of breath, and fatigue. Digoxin is used to reduce some symptoms of heart failure. It strengthens the contractions of the heart and helps it to pump blood more efficiently. Digoxin will not cure arrhythmias or heart failure, which are long term conditions, but can, along with diet, exercise, and other medicines, help to manage the symptoms. Digoxin levels need to be monitored because digoxin is a drug that has a narrow safety range. If the level in the blood is too low, symptoms may recur. If the level is too high, side effects may occur, such as:dizziness blurred vision or seeing yellow or green halos nausea and vomiting diarrhoea irregular heartbeat difficulty breathing rash The amount of digoxin you are prescribed may be adjusted based on the results of your blood test. How is the sample collected for testing? A blood sample is collected by inserting a needle into a vein in the arm. Is any test preparation needed to ensure the quality of the sample? No special preparation is needed, but timing of the sample for testing is important. When you have your blood taken, tell the healthcare professional when you took your last dose of digoxin. You may want to write down the exact time at which you took your dose and when the blood was taken. This information will be useful if your doctor has any questions about your results. See MoreSee Less

Preparation for the Test

No special preparation is needed, but timing of the sample for testing is important. When you have your blood taken, tell the healthcare professional when you took your last dose of digoxin. You may want to write down the exact time at which you took your dose and when the blood was taken. This information will be useful if your doctor has any questions about your results.

Sample Requirements

A blood sample collected from a vein in your arm

Additional Notes

Several prescribed and over-the-counter drugs can affect the level and effectiveness of digoxin in your system. Be sure to tell your doctor about all other medicines you may be taking.Digoxin is mainly removed from your blood by the kidneys. Tell your doctor if you have, or have had, kidney problems. Your doctor may want to measure blood potassium levels since low levels of potassium can result in symptoms of toxicity.If toxic levels are found, reducing the dose of digoxin or stopping the drug for a short time is sufficient to bring levels back to normal quickly. In severe cases where highly toxic levels of digoxin are measured, anti-digoxin antisera may be given to reverse the effects of the drug.

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