Effective half-life in clinical pharmacology. This pharmacokinetic phenomenon is reflect underestimation of terminal half-life after single dose.
Mechanism is distributional or protein binding.
The half-life measured for gentamicin does not actually represent the terminal elimination phase since the beta phase is followed by a much longer washout phase reflecting the slow release of gentamicin from renal tissue. The half-life of the deep tissue accumulation phase reflects a much slower deep tissue binding process not concerned with elimination of the drug from the body. In effect, these equations can used to dose most drugs which exhibit linear pharmacokinetics. In reality however, virtually all drugs obey multicompartment pharmacokinetics. Although phenytoin obeys nonlinear kinetics, the author was able to dose several patients using the apparent half-life of phenytoin in each patient.