Time-dependent inhibition (TDI) of CYP metabolism can generally be classified into three types: reversible, quasi-irreversible and irreversible. In general, TDI results from irreversible covalent binding or quasi-irreversible non-covalent tight binding of a chemically reactive intermediate to the enzyme that catalyses its formation. This results in loss of enzyme function and can cause clinically relevant drug-drug interactions (DDI). In some cases, reversible inhibition of a metabolite(s) generated in situ could give rise to TDI.
TDI inhibitory effect lasts longer than reversible inhibition and persists after elimination of the parent drug from the body because CYP activity can only recover with new enzyme synthesis.