Drug PD interaction model

Dear Nonmem users, I am looking for a model or a paper where it is reported that describes the interaction of three drugs, which act on the same PD parameter, however, two of them via independent mechanisms, whereas the third shares the mechanism of action, e.g., receptor, with one of the first two drugs. Any help, reference or direct modelling support, is appreciated and thanked for in advance. Best wishes Jorn Lotsch -- _______________________________________________________ Univ.-Prof. Dr. med. Jörn Lötsch pharmazentrum frankfurt/ZAFES Institut für Klinische Pharmakologie Goethe-Universität Theodor-Stern-Kai 7 D-60590 Frankfurt am Main Tel.:069-6301-4589 Fax.:069-6301-7636 http://www.klinik.uni-frankfurt.de/zpharm/klin/