We extend the nonstandard finite difference method of solution to the study of pharmacokinetic-pharmacodynamic models. Pharmacokinetic (PK) models are commonly used to predict drug concentrations that drive controlled intravenous (I.V.) transfers (or infusion and oral transfers) while pharmacokinetic and pharmacodynamic (PD) interaction models are used to provide predictions of drug concentrati...

In this paper, the reorganization of the denominator of the discrete derivative and nonlocal approximation of nonlinear terms are used in the design of nonstandard finite difference schemes (NSFDs). Numerical examples confirming then efficiency of schemes, for some differential equations are provided. In order to illustrate the accuracy of the new NSFDs, the numerical results are compared with ...

A nonlinear mathematical model of COVID-19 containing asymptomatic as well symptomatic classes infected individuals is considered and examined in the current paper. The largest eigenvalue next-generation matrix known reproductive number obtained for model, serves an epidemic indicator. To better understand dynamic behavior continuous unconditionally stable nonstandard finite difference (NSFD) s...

In this work, we derive a nonstandard finite difference scheme for the SICA (Susceptible–Infected–Chronic–AIDS) model and analyze dynamical properties of discretized system. We prove that is dynamically consistent with continuous, maintaining essential standard model, namely, positivity boundedness solutions, equilibrium points, their local global stability.