[Digitalis intoxication secondary to treatment with clarithromycin]

Area of Science:

• Pharmacology
• Clinical Pharmacy

Background:

• Digoxin is a cardiac glycoside used for heart failure and arrhythmias.
• Clarithromycin is a macrolide antibiotic with known drug interaction potential.

Observation:

• This retrospective study analyzed inpatients receiving both digoxin and clarithromycin.
• Serum digoxin concentrations were monitored to assess potential drug interactions.

Findings:

• 11.5% of patients on concurrent digoxin and clarithromycin showed supratherapeutic digoxin levels.
• Three patients experienced digitalis intoxication, likely due to the drug interaction.
• Inadequate dosing or insufficient interaction time accounted for other cases of elevated levels.

Implications:

• Concurrent administration of digoxin and clarithromycin necessitates careful monitoring of serum digoxin concentrations.
• This interaction poses a risk of digitalis toxicity, requiring clinical vigilance.
• Pharmacists and clinicians should be aware of this interaction to ensure patient safety.