[Serum digitoxin levels in pacemaker patients]

Area of Science:

• Cardiology
• Clinical Pharmacology

Context:

• Pacemaker patients, often elderly, present challenges in diagnosing digitalis toxicity using traditional ECG and clinical signs.
• Digitalis therapy is common in this demographic, necessitating reliable methods for monitoring drug levels.

Purpose:

• To determine serum digitoxin concentrations in pacemaker patients.
• To correlate these concentrations with clinical, ECG, and chemical findings.
• To assess the predictability of subtherapeutic, therapeutic, and toxic serum digitoxin ranges using multivariate analyses.

Summary:

• Serum digitoxin concentrations were measured in 200 pacemaker patients.
• Correlations with compliance, potassium, weight, and digitoxin dose were poor, and no correlation was found with ECG or clinical findings.
• Multivariate analysis predicted serum digitoxin ranges with up to 79% probability using compliance, body weight, and digitoxin dose.

Impact:

• Findings suggest that traditional diagnostic methods for digitalis toxicity are unreliable in pacemaker patients.
• Regular monitoring of serum digitoxin concentrations is recommended.
• Indications for digitalis therapy in this population require careful review.