An approach to the residence time distribution for stochastic multi-compartment models

Math Biosci. 2004 Oct;191(2):185-205. doi: 10.1016/j.mbs.2004.06.005.

Abstract

Stochastic compartmental models are widely used in modeling processes such as drug kinetics in biological systems. This paper considers the distribution of the residence times for stochastic multi-compartment models, especially systems with non-exponential lifetime distributions. The paper first derives the moment generating function of the bivariate residence time distribution for the two-compartment model with general lifetimes and approximates the density of the residence time using the saddlepoint approximation. Then, it extends the distributional approach to the residence time for multi-compartment semi-Markov models combining the cofactor rule for a single destination and the analytic approach to the two-compartment model. This approach provides a complete specification of the residence time distribution based on the moment generating function and thus facilitates an easier calculation of high-order moments than the approach using the coefficient matrix. Applications to drug kinetics demonstrate the simplicity and usefulness of this approach.

Publication types

  • Comparative Study

MeSH terms

  • Anticholesteremic Agents / administration & dosage
  • Anticholesteremic Agents / pharmacology
  • Body Fluid Compartments
  • Feedback, Physiological / physiology
  • Humans
  • Hypercholesterolemia / drug therapy
  • Hypercholesterolemia / metabolism
  • Markov Chains
  • Models, Biological*
  • Pharmacokinetics*
  • Pravastatin / administration & dosage
  • Pravastatin / pharmacokinetics
  • Stochastic Processes*

Substances

  • Anticholesteremic Agents
  • Pravastatin