What are the parameters to hold digoxin (digitalis glycoside)?

From the Guidelines

Digoxin should be held if the serum digoxin level exceeds 2.0 ng/mL, if the patient has signs of digoxin toxicity, or if the heart rate is below 60 beats per minute. Signs of toxicity include nausea, vomiting, visual disturbances (yellow-green halos around objects), confusion, and cardiac arrhythmias, as noted in the 2013 ACCF/AHA guideline for the management of heart failure 1. Additionally, hold digoxin if the patient has significant electrolyte abnormalities, particularly hypokalemia (potassium <3.5 mEq/L), hypomagnesemia, or hypercalcemia, as these conditions increase sensitivity to digoxin and risk of toxicity.

Key Considerations for Holding Digoxin

• Renal function should also be monitored, and digoxin should be held if there is acute kidney injury or significant worsening of renal function, as digoxin is primarily eliminated by the kidneys, as discussed in the 2009 focused update incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management of heart failure in adults 1.
• The concomitant use of certain drugs, such as clarithromycin, erythromycin, amiodarone, itraconazole, cyclosporine, verapamil, or quinidine, can increase serum digoxin concentrations and may increase the likelihood of digitalis toxicity, highlighting the need for careful management and monitoring.
• After holding digoxin, reassess the patient's clinical status, correct any electrolyte abnormalities, and check digoxin levels before resuming therapy, ensuring a cautious approach due to digoxin's narrow therapeutic window.

Monitoring and Management

• The dose of digoxin should be reduced if treatment with drugs that can increase serum digoxin concentrations is initiated, as noted in the guidelines 1.
• A low lean body mass and impaired renal function can also elevate serum digoxin levels, which may explain the increased risk of digitalis toxicity in elderly patients, emphasizing the importance of individualized dosing and monitoring.
• Women may not benefit from digoxin therapy and may be at increased risk for death with such therapy, as suggested by one analysis, underscoring the need for careful consideration of the benefits and risks in this population.

From the FDA Drug Label

About two-thirds of adults considered adequately digitalized (without evidence of toxicity) have serum digoxin concentrations ranging from 0.8 to 2. 0 ng/mL. The maintenance dose should be based upon the percentage of the peak body stores lost each day through elimination.

The therapeutic range for digoxin is generally considered to be between 0.8 and 2.0 ng/mL.

• Hold parameters for digoxin are not explicitly stated, but as a general guideline, digoxin levels above 2.0 ng/mL may indicate toxicity, and levels below 0.8 ng/mL may indicate inadequate digitalization.
• It is essential to interpret serum digoxin concentrations in the overall clinical context, considering factors such as renal function, age, and lean body weight 2.

From the Research

Hold Parameters for Digoxin

To determine the hold parameters for digoxin, several factors must be considered, including the patient's serum digoxin level, renal function, and clinical symptoms of toxicity.

• The therapeutic range for digoxin is generally considered to be between 0.5 and 2.0 ng/mL, with levels above 2.4 ng/mL considered toxic 3.
• Patients with serum creatinine levels above 1.4 mg/dL are at increased risk of digoxin toxicity due to impaired renal function 3.
• Clinical symptoms of digoxin toxicity include electrocardiographic changes, nausea, vomiting, and visual disturbances.
• The decision to hold digoxin should be based on the individual patient's risk factors and clinical presentation.

Risk Factors for Digoxin Toxicity

Several risk factors have been identified for digoxin toxicity, including:

• Elderly patients, particularly those with impaired renal function and low body weights 3.
• Patients with congestive heart failure and normal sinus rhythm, who may not derive significant benefit from digoxin therapy 3.
• Patients with new onset atrial fibrillation, who may be at increased risk of digoxin toxicity due to rapid atrial fibrillation 3.
• Patients with impaired renal function, who are at increased risk of digoxin accumulation and toxicity 3, 4.

Management of Digoxin Toxicity

The management of digoxin toxicity involves supportive care and, in severe cases, the use of digoxin immune Fab to decrease the risk of death 5.

• Patients with suspected digoxin toxicity should be closely monitored for clinical symptoms and electrocardiographic changes.
• The use of digoxin immune Fab should be considered in patients with life-threatening digoxin toxicity 5.
• A thorough review of the patient's medication regimen and renal function should be performed to identify potential contributing factors to digoxin toxicity 3, 4.