The changing pattern of toxicity of digoxin

Area of Science:

• Pharmacovigilance
• Clinical Pharmacology
• Drug Safety

Background:

• Digoxin is a critical medication for heart conditions, but its narrow therapeutic index necessitates careful monitoring for toxicity.
• Previous studies indicated significant risks associated with digoxin, prompting further investigation into current toxicity profiles.
• Comprehensive drug surveillance programs are essential for understanding real-world adverse event patterns.

Purpose of the Study:

• To assess the incidence and nature of digoxin toxicity in a large cohort of consecutive recipients.
• To identify risk factors for digoxin-related adverse events and compare findings with prior research.
• To evaluate the impact of improved prescribing practices on digoxin toxicity rates.

Main Methods:

• Prospective monitoring of 437 consecutive patients receiving digoxin.
• Systematic recording and analysis of all reported adverse reactions.
• Statistical evaluation of patient demographics, comorbidities, and concurrent medications as potential risk factors.

Main Results:

• Adverse reactions occurred in 19.5% of patients, predominantly benign, with no drug-related deaths.
• Low body weight, renal impairment, advanced age, and diuretic use did not individually increase toxicity risk.
• A significant excess of early gastrointestinal reactions was observed in female patients, a susceptibility not widely recognized.

Conclusions:

• Current digoxin prescribing practices appear to have reduced toxicity risks compared to historical data.
• Female patients exhibit a specific susceptibility to early-onset gastrointestinal digoxin toxicity.
• Abandoning routine loading doses, except in critical situations, may mitigate early adverse reactions.