====== Kinetics Problems ======

===== PROBLEM 1 =====

Consider the effect on free drug concentration of an increase in protein binding of 1% for 3 drugs whose protein bindings are 95%, 80% and 50%.

Would there be any difference if the change in protein binding occured in minutes versus over 2 weeks?

===== PROBLEM 2 =====

A 50 kilogram woman ingests 5000 mg of controlled release theophylline. The average Vd for theophylline is 0.5 litres/kg.

  - What is the likely peak concentration if it is fully absorbed?
  - Theophylline is metabolised by P450 enzymes. What is the likely impact of this dose on theophylline’s metabolism and elimination?
  - The half-life was calculated using 2 levels 6 hours apart. The half-life appeared to be 10 hours. What factors may contribute to this result. What are some of the potential sources of error in such a calculation?