Question

In the given picture, which kinetic order the graph is following at the marked place?

(a) 1st order kinetics

(b) 2nd order kinetics

(c) Mixed order kinetics

(d) 1st order at higher doses

This question was posed to me at a job interview.

I want to ask this question from Non Linearity of Drugs topic in section Compartment Modelling, Non Linear Pharmacokinetics, Bioavailability and Bioequivalence of Drug Biotechnology

Answer 1

The correct answer is (c) Mixed order kinetics

The explanation: The plot is of Michaelis-Menten equation –dC/dt = Vmax C/Km+C, Initially the rate increases linearly with concentration thus showing first order kinetics. It becomes mixed order at intermediate doses and then reaches maximum Vmax. Beyond this, it proceeds at a constant rate.