Interpretation of digoxin blood levels by programmable calculator

Area of Science:

• Pharmacokinetics
• Clinical Pharmacology
• Medical Informatics

Background:

• Accurate monitoring of drug levels is crucial for effective and safe patient treatment.
• Digoxin is a common medication requiring careful dosage adjustment to maintain therapeutic blood levels.
• Programmable calculators offer a portable and accessible tool for complex calculations.

Purpose of the Study:

• To evaluate the utility of a computer algorithm on a hand-held calculator for determining steady-state digoxin blood levels.
• To assess the correlation between calculated and measured digoxin concentrations in patients.
• To determine the feasibility of using programmable calculators for precise drug therapy management.

Main Methods:

• A programmable hand-held calculator was programmed using the Wagner-Northam steady-state equation.
• The algorithm was tested using data from 14 patients receiving digoxin.
• Digoxin blood levels were quantified using radioimmunoassay for comparison.

Main Results:

• The calculated digoxin levels correlated well with measured levels in nine out of 14 patients.
• Discrepancies in five patients were attributed to underestimated half-life, charting errors, or unusual digoxin elimination.
• The study demonstrated the potential for programmable calculators to improve therapeutic precision.

Conclusions:

• Programmable calculators can be effectively utilized to calculate steady-state digoxin blood levels.
• This approach offers a practical method for enhancing the precision of drug therapy planning and monitoring.
• Further investigation into discrepancies can refine the algorithm's accuracy and clinical applicability.