Test Code DIG 
Methodology Immunoassay 
Description Useful for monitoring the dosage of digoxin to guard against toxicity.

NOTE: This test, when ordered on Medicare patients, is subject to the National Coverage Determination (NCD) policy "Digoxin Therapeutic Drug Assay". Please verify that the diagnosis code (ICD-9) you have chosen demonstrates medical necessity for the test as documented in the physician's patient record. The CMS web site or the NorDx Limited Coverage Documentation Guide are available to assist you with this verification. A properly executed Advance Beneficiary Notice (ABN) must be submitted with the specimen if medical necessity is not demonstrated by the ICD-9 code chosen. 

Specimen Draw blood in either a plain, red-top tube or serum gel tube. Spin down and send 0.5 mL (0.3 mL minimum) of serum refrigerated. For better correlation of serum and tissue concentrations, Digoxin specimens should be drawn six hours post dose. 
MMC Specimen Draw blood in a plasma gel tube. 0.5 mL of plasma required. 
Reference Values Therapeutic range: 0.7 - 0.9 ng/mL
Toxic concentration: > 2.5 ng/mL

When digoxin is used in the treatment of heart failure, the serum digoxin level should be measured 7 to 10 days after starting digoxin or changing the dose of digoxin, at which point a steady state should have been achieved. For patients with heart failure, maintaining a digoxin level between 0.7 and 0.9 ng/mL is suggested for maximal efficacy with minimal risk of toxicity. 

Analytic Time 1 Day - Available STAT 
Day(s) Test Set Up Monday through Sunday 
CPT Code(s) 80162