A novel compartmental modelling approach to investigate influx and efflux distribution of the drug efavirenz is suggested. The models are developed for a patient who had been on 600 mg daily dose of efavirenz. The work makes use of suggested wave motion to model drug distribution. It offers new insights into PK-PD(Pharmacokinetic-Pharmacodynamic) modelling. The distributional systems (immission and emission) of efavirenz are investigated and models are suggested. Each of the two distributional systems consists of four descriptors a source (desorbate), an underlay(a substrate/stimulus), a facilitator (propeller) and a product (adsorbate). The immission distribution is responsible for adsorbate formation. The immission distributional kinetics model is applied in projecting bioavailability (F = 0.194 5), extrinsic pass effects availability , immission distributional volumes , elimination rate constants and clearance parameters . Furthermore, the emission system model introduces a two-phased uptake for distribution of the efavirenz solution particle. The emission distribution is responsible for adsorbate degradation. It establishes a concentration-dependent peripheral uptake and a central one which is independent of concentration. The two distributional systems (waves) proposes a basis and subsequent space for a linear response. An elasticity measure is suggested for resistance to distributional flow. The developed models show how concentration can be used to characterise and predict distributional kinetics. Several relationships can be inferred from models suggested herein such as links to assertations from the Navier–Stokes and Noyes-Whitney equations.