Digoxin
Code:
DIG
Sample Type:
Serum (Gold Top)
Minimum volume: 1 mL
Ref Ranges/Units:
Therapeutic range 0.5 – 2.0 μg/L
Target range in heart failure 0.5 – 1.0 μg/L
Results >2.5 μg/L will be phoned to the requesting clinician.
Turnaround:
Same Day (60 minutes from receipt for Urgent Samples)
Stability:
7 days at 15‐25°C
14 days at 2‐8°C
6 months at ‐20°C
Freeze only once
Special Precautions/Comments:
Must be >6 hours post dose.
Takes 7 days to reach steady state.
Additional Information:
Digoxin is cardiac glycoside prescribed for heart failure and for atrial fibrillation or flutter. It acts to increase force of myocardial contraction and reduces conductivity within the atrioventricular (AV) node. Digoxin therapy results in increased cardiac output and a stabilised and slowed ventricular pulse rate.
Digoxin has a narrow therapeutic window and high doses are associated with toxicity. Therapeutic drug monitoring allows the optimal therapeutic dose to be achieved by avoiding both subtherapeutic and toxic levels.
Although overt digoxin toxicity is associated with levels >2.0 ug/L, results should be interpreted in the clinical context as toxicity may occur even within the therapeutic range. Digoxin shows greater toxicity in renal impairment, hypokalaemia, hypomagnesaemia or hypercalcaemia.
South of Tyne & Wear Pathology Centre
