Digoxin, Plasma

Overview
Department	Biochemistry
Test Code	DIG
Synonyms	Digitalis
Test Availability	Monday - Sunday, testing routinely available out of hours
Turnaround Time	1 – 5hrs
Stability – Add test	8 hours
Specimen Requirements
Specimen Type	Serum Plasma
Specimen Transportation
Preferred	6 mL Red-Top
Acceptable	6 mL Li-Hep Green-Top
Unacceptable
Paediatric Requirements	Li-Heparin Microtainer
Aliquot Requirements
Sample Type	Serum Plasma
Preferred Volume	500 µL
Minimum Volume	200 µL
Aliquot Transportation
Clinical Information
Reference Intervals	Range 0.6 - 2.0 nmol/L Toxic levels >2.0 nmol/L
Test Method	Abbott Alinity Ci, Particle-enhanced turbidimetric inhibition immunoassay (PETINIA)
Advanced Notice	Not required
Patient Preparation	Samples are best taken at the trough, just before the next dose, or at least 8-12 hours post-dose, to avoid falsely high results due to delayed drug distribution after the dose.
Comments
Specimens from patients treated with Digoxin immune FAB (Digibind) should be viewed with caution, as this substance is known to inhibit the assay. Heterophilic antibodies have been shown to interact with immunoglobulin reagents in some immunoassay systems.