Prescribing Notes
- Seek specialist advice before initiating digoxin in heart failure.
- Refer to NICE NG106 Chronic heart failure in adults and NICE NG196 Atrial fibrillation.
- Digoxin may be a useful adjunct to a beta-blocker for heart rate control but assessment of heart rate/rhythm is required and doses more than 125 micrograms in this setting are generally best avoided.
- Regular measurements of plasma digoxin concentrations are not usually required except to confirm toxic levels, or to check compliance. Blood should be taken at least 6 hours after the last dose of digoxin. Laboratories in NI offer a normal range. Refer to the Digoxin monitoring guidance for further information.
- There is no therapeutic dose response relationship for digoxin in heart failure. Increasing doses >250 micrograms just increases toxicity.
- If toxicity occurs, digoxin should be withdrawn; serious manifestations require urgent specialist management. For further information on the management of toxicity see Toxbase or contact UK National Poisons Information Service on 0844 892 0111.
- Digoxin should not be used in the treatment of patients with pre-excitation syndromes, e.g. Wolff-Parkinson-White Syndrome, unless specifically prescribed by a specialist.
Cautions
- Loading and maintenance doses of digoxin should be adjusted according to renal function. Age, sex and weight need to be considered. Seek specialist advice if there is any clinical uncertainty. A maintenance dose of ≤125 micrograms daily is adequate in most patients. A lower maintenance dose (i.e. 62.5 micrograms daily) is often adequate in older patients, in patients with renal failure and in patients taking potentiating therapy.
- Digoxin should be used with particular caution in the elderly and patients with renal impairment.
- Hypokalaemia predisposes digoxin toxicity. Care should be taken to monitor the electrolytes when prescribing diuretics. Consider use of appropriate potassium-sparing diuretics, or combination with ACE inhibitor/ARB as appropriate.