Theophylline serum protein binding in obstructive airways disease

Area of Science:

• Pharmacology
• Clinical Chemistry

Background:

• Theophylline is a crucial medication for obstructive airways disease.
• Understanding its protein binding is essential for effective therapeutic drug monitoring.

Purpose of the Study:

• To quantify theophylline protein binding in patients with obstructive airways disease.
• To investigate factors influencing theophylline binding, including patient demographics and serum protein levels.

Main Methods:

• Ultrafiltration was used to determine the percentage of theophylline bound to protein in serum samples.
• Serum specimens were collected from 51 patients with obstructive airways disease.
• Correlations with serum albumin, total protein, age, and sex were analyzed.

Main Results:

• The mean theophylline bound fraction was 60.7% (range 30.8%–83.2%), with significant interpatient variability.
• A strong linear correlation was observed between unbound and total serum theophylline concentrations (r = 0.97).
• Theophylline binding was higher in younger patients compared to those over 55 and showed weak correlations with albumin and total protein.

Conclusions:

• Significant interpatient variability in theophylline protein binding exists in obstructive airways disease patients.
• This variability influences theophylline's distribution and elimination, affecting clinical outcomes.
• Individualized dosing adjustments based on protein binding are recommended for optimal theophylline therapy.