## Dose-proportionality versus dose-linearity [PK / PD]

Dear martin,

I must admit I am a bit relieved to see that apparently there is some general confusion around this topic .

Your example 1. makes sense to me. Do you have an example for 2.?

Maybe we can go one step back and clarify nomenclature. When you talk about "linear PK" you apparently do not mean the same thing as dose proportionality. Are you using "linear PK" interchangebly to "dose linearity"? I see all kinds of definitions, some define linear PK to be dose proportionality, some don't. Of course it always depends on the underlying model (how many compartments?)... Is there a general definition of the three terms?

Thanks
Ben.