Test Code DIG Digoxin, Random
Additional Codes
Epic: LAB23
Specimen Required
Specimen Type: Serum
Collection Container/Type: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 3.5 mL
Collection Instructions:
- Collect immediately before next dose (or at a consistent sampling time).
- Centrifuge within 1 hour of collection.
Additional Information:
- Provide date and time of last dose.
Specimen Minimum Volume
0.2 mL
Specimen Stability
Room temperature: 2 days
Refrigerated: 2 days
Frozen: 6 months
Reference Range
Therapeutic range: 0.5 - 2.0 ng/mL
Rejection Due To
Unlabeled, mislabeled, wrong tube type, QNS, gross hemolysis
Report Available
Same day
Clinical Significance
Digoxin is a potent cardiac glycoside used to treat atrial fibrillation with rapid ventricular response, and to treat congestive heart failure. Test results are used to monitor levels of digoxin because the drug has a low therapeutic ratio (a small difference between therapeutic and tissue toxic levels), and because the symptoms of drug overdose may resemble the original condition for which the drug was prescribed. Also, digoxin dosage may require adjustment when renal function is impaired or when drugs known to alter the pharmacokinetics of digoxin are co-administered. Monitoring serum or plasma digoxin levels along with other clinical data can aid the physician in adjusting patient dosage to achieve optimal therapeutic effect while avoiding sub-therapeutic or toxic dosage levels. Toxic symptoms may occur at levels lower than critical limit. Steady state is reached in 5 days. Digoxin has an average half-life of 48 hours, is 25% protein bound, and is cleared by the kidneys.
Method Name
Chemiluminescent Microparticle Immunoassay (CMIA).
Limitations
Heterophile antibodies may interfere, causing anomalous values.
Digoxin active metabolites may cross-react with methodology, which may affect test results especially in patient with renal impairment.
Endogenous digoxin-like immunoreactive factors (DLIF) found in serum of neonates, pregnant women, and in patients with renin hypertension, renal and/or hepatic failure may cause falsely elevated digoxin values.
Digoxin bound to F(ab) fragments of anti-digoxin antibodies (DIGIBIND, DIGIFAB), found in serum of patients treated for digoxin toxicity, may result in misleading digoxin values.
Quinidine may cause digoxin values to be elevated by decreasing digoxin excretion.
Day(s) Performed
Daily