| Laboratory: | Clinical Biochemistry (AUTOMATED) |
| Test Name: |
DIGOXIN, Rural Sites (ORTHO), excluding Westman Lab - (S)
Test Code:
DIG
|
| Clinical Information: |
Alternate Name(s): Toloxin, Lanoxin
Description: Digoxin is a cardiac glycoside, widely used for the treatment of congestive heart failure and disturbances of cardiac rhythm. Test Indications: Routine Digoxin monitoring is not recommended and should not be used to guide chronic therapy. Digoxin levels are most useful when assessing for toxicity. Patients with reduced renal function, elder patients, and those with low body mass are at increased risk of Digoxin toxicity and may require closer monitoring. Patient preparation instructions: Samples should be collected at trough levels, just prior to the next dose of Digoxin, or at least 12 hours since the last dose (oral or IV). Steady state concentrations of Digoxin take approximately 1 week to be achieved after initiation of therapy. If toxicity is suspected, specimens may be drawn at any time. |
| Collection Devices: |
Preferred Device:
|
| Specimen Required: |
Serum: 2.0 mL
Collection Information: Serum collected without gel. Plasma specimens are not acceptable. Special Processing: Centrifuge specimens and remove the serum from the cellular material within 4 hours of collection. Specimen Stability: Refrigerated: 7 days Frozen: 4 months (freeze only once) |
| Referral: |
Serum: 2.0 mL
Specimen Type: Serum, no gel
Samples must be transferred to an aliquot tube and stored frozen if analysis will not be complete within 48 hours (#110-10-05 Serum / Plasma Separation Procedure & Transport) Testing Laboratory (MB): Dauphin, Portage la Prairie, Selkirk, Steinbach, Boundary Trails |
| Requisition: | |
| Reference Values: |
Reference Intervals:
Therapeutic: 0.8 – 2.0 μg/L Toxic: > 2.4 μg/L Diagnosis of Digoxin toxicity should be based on the combination of clinical and biochemical findings. Critical Value:> 2.5 μg/L Method of Analysis: Dry-slide competitive immunoassay |
| Availability: |
Daily or Stat
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| See Also: | |
| More Information: |
Interpretation & Assay Interferences: Digoxin Like Immunoreactive Substances (DLIS) present in patient samples can result in falsely elevated or lowered Digoxin values when tested by immunoassay. Patient populations which are at higher risk of developing DLIS include those with renal failure, liver failure, in the 3rd trimester of pregnancy, or those who have been taking Digoxin for several years.
Rarely, interference due to extremely high antibody titres against assay components can cause spurious results. References: 1. Ortho-Clinical Diagnostics. (2019). VITROS DGXN Slides. [Package Insert; v 12.0 Eng]. Rochester, NY. 2. Dasgupta A. 2002. Endogenous and exogenous digoxin-like immunoreactive substances: impact on therapeutic drug monitoring of digoxin. Am J Clin Pathol. 118: 132-140 3. Ezekowitz JA, O’Meara E, McDonald MA et al. 2017. Can J Cardiol. 33(11) : 1342-1433. |