Digoxin, Free
Test Mnemonic
DIGFR
CPT Codes
- 80163 - QTY (1)
LOINC ®
3562-6
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | SST (Gold) | Refrigerated | Collect specimen 6 to 8 hours after last dose. Centrifuge and aliquot specimen within 2 hours of collection. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | No additive (Red) | Refrigerated | Collect specimen 6 to 8 hours after last dose. Centrifuge and aliquot specimen within 2 hours of collection. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.5 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Unacceptable |
| Refrigerated | 7 days |
| Frozen | 180 days |
Days Performed
Sun - Sat
Turnaround Time
2 - 3 days
Methodology
| Name | Description |
|---|---|
| Electro Chemiluminescence Immunoassay (ECLIA) | |
| Ultrafiltration (ULT) |
Reference Range
| Digoxin, Free | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| < 16 years: Therapeutic ranges have not been established | > or = 16 years: Therapeutic range: 0.4 - 0.9 ng/mL | Critical | Toxic concentration: > or = 3.0 | ng/mL |
Special Info
Grossly hemolyzed specimens will be rejected. This test is New York State approved.
Clinical Info
Useful for evaluating recrudescent (breakthrough) digoxin toxicity in renal-failure patients; assessing the need for more antidigoxin Fab to be administered; deciding when to reintroduce digoxin therapy, and monitoring patients with possible digoxin-like immunoreactive factors (DLIFs). The suggested therapeutic range is 0.4 - 0.9 ng/mL for patients > or = 16 years of age. Toxicity may be seen when free digoxin concentrations are > or = 3.0 ng/mL. Therapeutic ranges have not been established for patients < 16 years of age. Pediatric patients may tolerate higher concentrations. Therapeutic concentrations for free digoxin are 25% lower than therapeutic values for total digoxin due to the separation of protein-bound digoxin in the assay.