myUpchar प्लस+ के साथ पूरेे परिवार के हेल्थ खर्च पर भारी बचत

What is Digoxin test?

Digoxin is a drug that is used in the treatment of heart failure (congestive heart failure) and abnormalities in the heartbeat (arrhythmia). It decreases the rate of heartbeat, increases the force of contraction of heart muscles and delays the passage of electric impulse in the heart that causes contraction of the heart.

A digoxin test is a blood test that measures the levels of digoxin and its breakdown products (metabolites) in the bloodstream. Since excess digoxin can be harmful to the body, this test is done at repeated intervals after the administration of this drug to monitor drug dose and avoid its toxic effects in those suffering from heart failure and arrhythmia.

  1. Why is a Digoxin test performed?
  2. How do you prepare for a Digoxin test?
  3. How is a Digoxin test performed?
  4. What do Digoxin test results mean?

A digoxin test is done to adjust the dosage of this drug according to the age, severity of the disease and health condition of an individual so as to obtain the desired effects of the drug. The process is called therapeutic drug monitoring (TDM). TDM of digoxin also helps in determining whether it is suitable to use when you are suffering from other disease conditions or taking medicines that increase the levels of digoxin. Increased age, being underweight, increased calcium and low levels of potassium and magnesium in the blood and kidney diseases are some of the high-risk factors for digoxin toxicity. Doctors order digoxin test when the following symptoms that indicate digoxin toxicity are seen:

  • Nausea
  • Loss of appetite
  • Diarrhoea
  • Vomiting
  • Drowsiness with confusion of mind
  • Disturbances in vision: hazy or unclear vision; appearence of a yellow or green colour halo around objects 

No special preparation is needed for this test. Inform your doctor if you are taking medicines for high cholesterol, high blood pressure (calcium channel blockers) or heart problems, or antibiotics for certain infections. Medicines that contain amiodarone, verapamil, diltiazem, ciclosporin, quinine and atorvastatin increase the level of digoxin in the blood.

A laboratory technician or the nurse will collect your blood sample in a red-top tube and will send it immediately for analysis. 

The first sample is usually collected from six to 12 hours after the drug (digoxin) is taken by mouth and four to six hours after intravenous injection of the drug. Subsequent blood samples are collected after 24 hours and one week to analyse the desired level (therapeutic level) of the drug in the blood, which would not lead to any harmful effect.

Blood tests to measure the levels of potassium, creatinine, magnesium and calcium are done before the digoxin test. Mild side effects such as infection, bleeding and accumulation of blood under the skin at the site of needle prick are seen after the digoxin test.

Normal results:

The ideal levels or normal therapeutic range of digoxin in blood, which are beneficial in the treatment of heart failure and arrhythmia are 0.5-2 ng/mL (nanograms per millilitre) and 1.5-2.5 ng/mL, respectively.

Abnormal results: 

Values higher than the normal results indicate the following:

  • Digoxin toxicity
  • Kidney diseases
  • Use of drugs such as amiodarone, calcium channel blocker medicines, antibiotics (ciclosporin, quinine, etc.) and so on along with digoxin

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.

और पढ़ें ...

References

  1. The Johns Hopkins University [Internet], The Johns Hopkins Hospital, and Johns Hopkins Health System; Drugs treating heart failure
  2. Marshall WJ, Lapsley M, Day AP, Ayling RM. Clinical Biochemistry: Metabolic and Clinical Aspects. 3rd ed. 2014. Pp:767,770.
  3. Wilson DD. McGraw-Hill’s Manual of Laboratory Diagnostic Tests. Therapeutic Drug Monitoring. 2008. Pp:536.
  4. Daily Med [internet]. National Institute of Health. US National Library of Medicine: Bethesda (MA), US. US Department of Health and Human Services Label: Digoxin- digoxin tablet
  5. Whittlesea C, Hodson K. Clinical Pharmacy and Therapeutics. Arrhythmias. 6th ed. 2019. Ebook. Pp:400.
  6. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; Digoxin Medicine Level
  7. Wirral University Teaching Hospital [internet]: NHS Foundation Trust. National Health Service. U.K., Therapeutic drug monitoring
  8. Provan D. Oxford Handbook of Clinical and Laboratory Investigation. Poisoning and Overdose. 4th ed. 2018. Pp:718.
  9. Fischbach FT. A Manual of Laboratory and Diagnostic Tests, 7th ed, 2003 Lippincott Williams & Wilkins Publishers pp 275
  10. Ferri FF. Ferri’s Best Test. A Practical Guide to Clinical Laboratory Medicine and Diagnostic Imaging. Digoxin (Lanoxin). 4th ed. 2019. Pp:176.