Triazolam protein binding and correlation with alpha-1 acid glycoprotein concentration

Area of Science:

• Pharmacokinetics
• Clinical Chemistry
• Nephrology

Background:

• Drug binding to plasma proteins affects drug distribution and efficacy.
• Patients undergoing dialysis often exhibit altered plasma protein concentrations.
• Alpha 1-acid glycoprotein (AGP) is a key determinant of drug binding.

Purpose of the Study:

• To investigate the relationship between plasma protein concentrations and triazolam binding in patients on dialysis.
• To determine the role of albumin and AGP in modulating triazolam protein binding.

Main Methods:

• Plasma samples were collected from 12 dialysis patients.
• Concentrations of albumin and AGP were measured.
• 14C-Triazolam protein binding was assessed using equilibrium dialysis.

Main Results:

• Unbound triazolam constituted a mean of 10.0% of the total concentration.
• Triazolam binding ratio strongly correlated with AGP concentration (r2 = 0.69).
• No significant correlation was found between triazolam binding and albumin concentration, age, or sex.

Conclusions:

• Alpha 1-acid glycoprotein concentration is the primary determinant of triazolam plasma protein binding in dialysis patients.
• Albumin levels, patient age, and sex do not significantly influence triazolam binding in this population.
• These findings have implications for understanding triazolam pharmacokinetics in renal failure.