Digoxin - serum
Last updated: Tuesday, 30, March, 2004
| Item | Process |
|---|---|
| Specimen | 5 mL blood in plain tube. The blood specimen must be taken at least 6 hours after the last oral dose of digoxin (ideally 12 hours). |
| Method | Immunoassay. |
| Therapeutic Interval | 0.6-2.3 nmol/L (0.5-1.8 µg/L). |
| Application | Assessment of suspected digoxin toxicity or inadequate response. Digoxin half-life is 20-50 hours; prolonged with renal impairment. |
| Interpretation | Toxic levels: >2.6 nmol/L (>2.0 µg/L). The therapeutic interval is approximate, toxicity can occur at lower levels, especially if there is associated hypokalaemia. |
| Reference | Sidwell A et al. N Z Med J 2003; 12:116(1187):U708. |