|Description||For monitoring purposes, blood should not be drawn until a steady state has been attained. This will not be achieved until 1-3 weeks after starting therapy or changing dose.|
|Indication||Routine monitoring not necessary on patients on maintenance dose if satisfactory response and no toxicity.
|Additional Info||For monitoring purposes, blood should not be drawn until a steady state has been attained. This will not be achieved until 1-3 weeks after starting therapy or changing dose. Hypercalcaemia, hypomagnasaemia and hypothyroidism may increase sensitivity as will other causes of hypokalaemia e.g diarrhoea, corticosteroids, carbenoxolone. INDICATIONS FOR MONITORING: a) Initial poor response to treatment - serum digoxin will indicate level achieved and provide guidance on dosage increase
b) Helping to confirm diagnosis of toxicity although concomitant hypokalaemia must be taken into account c) When previous drug history is uncertain particularly in elderly patients receiving a number of drugs d) To facilitate discontinuation of therapy e) When renal function is deteriorating or fluctuating f) when drugs known to interfere or interact with digoxin are started or stopped e.g Verapamil and digoxin in intractable SVT- digoxin may be used at reduced dose.
|Interpretation||Reference range is only applicable for normokalaemic patients. If patient is hypokalaemic digoxin toxicity can occur when levels are within the reference range. Reduce dose if renal function is poor. NOTE: Reporting units changed from nmol/L to microgram/L May 1, 2007. NB: drugs which can cause INCREASED serum digoxin levels include: amiodarone, anticholinergic drugs, diltiazem, propafenone, quinidine, spironolactone, verapamil. Drugs which can cause DECREASED serum digoxin levels include: antacids, cholestyramine, domperidone, kaolin-pectin, metoclopramide, sulfasalazine|
|Tube||Serum or Heparin|
|Collection Conditions||Blood must be taken at least 6 hrs after last oral dose. Use gold top (serum gel) tube except for Intensive care units, renal unit, transplant unit, patients on IV heparin (use Green/yellow top tube for these patients).|
|Min. Vol||1 mL|
|Ref. Range (Male)||0.5 - 1.0 microgram/L |
|Ref. Range (Female)|| 0.5 - 1.0 microgram/L|
|Ref. Range (Paed)|| |
|Ref. Range Notes||1: Reporting units changed from nmol/L to microgram/L May 1, 2007.
2: Change in advised therapeutic range Nov 5, 2008.
|IP Acute TAT||Refer to Website|
|IP Routine TAT||Refer to Website|
|GP Acute TAT||- Contact Laboratory|
|GP Routine TAT||Refer to Website|
Originally edited by : MC. Review due on 12/01/2018 18:30:03. Published By Sylvia Bennett on 12/01/2017 18:30:03.