Cardiac glycosides (Formulary)

TAM (Treatments and Medicines) NHS Highland
NHS Highland

Hypokalaemia predisposes to digoxin toxicity and should be managed.  Take care when using diuretics alongside digoxin.  Give potassium supplements if necessary.  Plasma digoxin levels should not be done routinely but are indicated in the following situations: when toxicity is suspected; to assess lack of response ie suspected poor compliance; when an interacting medication is stopped or started (eg amiodarone, diltiazem, quinine, verapamil) or for patients with renal impairment (CrCl<20ml/min).  Symptoms of toxicity include: confusion, anorexia, nausea, vomiting, disturbance of colour vision, arrhythmia. Refer to Therapeutic Drug Monitoring summary.

DIGOXIN

Therapy notes

Maintenance dose depends on heart rate and renal function.
NICE CG180 Atrial fibrillation: management
Heart Failure
Refer to Therapeutic Drug Monitoring summary for further guidance on frequency of monitoring

Renal impairment (CrCl <50ml/min): Digoxin is renally excreted and is not dialysed.  Accumulation may result in toxicity.  Consider giving a reduced loading dose and assess clinical response prior to each additional dose.  The Cockcroft and Gault equation should be used to calculate CrCl and a reduced maintenance dose should be prescribed:

CrCl (ml/min)

Dose

Digoxin levels required?

20 to 50

125 to 250 micrograms daily

Not routinely

10 to 20

62∙5 to 125 micrograms daily

Yes

below 10

62∙5 micrograms on alternate days or daily

Yes

Formulation and dosage details

Formulation:

Tablets 62·5 micrograms, 125 micrograms, 250 micrograms

Dosage:

By mouth (preferred route), atrial fibrillation or heart failure, rapid digitalisation: 500 micrograms followed by 500 micrograms 4 hours later; maintenance, 62·5 to 250 micrograms daily (doses of greater than 62·5 to 125 micrograms are rarely required in the elderly). Maintenance dose depends on heart rate and renal function.

Formulation and dosage details

Formulation:

Oral solution 250 micrograms/5mL

Dosage:

By mouth (preferred route), atrial fibrillation or heart failure, rapid digitalisation: 500 micrograms followed by 500 micrograms 4 hours later; maintenance, 62·5 to 250 micrograms daily (doses of greater than 62·5 to 125 micrograms are rarely required in the elderly). Maintenance dose depends on heart rate and renal function.

Formulation and dosage details

Formulation:

Injection 500 micrograms/2mL

DIGOXIN-SPECIFIC ANTIBODY FRAGMENTS (F( ab))

Therapy notes

Formulation and dosage details

Formulation:

Powder for reconstitution for intravenous infusion 40mg/vial (DigiFab®) (Hospital use only)

Dosage:

For the treatment of digoxin overdose.

Editorial Information

Document Id: F038