1 Department of Urology, Agios Savvas Cancer Hospital, Athens 11522, Greece; 2 Department of Biochemistry and Biotechnology, University of Thessaly, Larissa 41500, Greece; 3 Immunology Laboratory, Immunology Department, Hellenic Pasteur Institute, Athens, Greece tamoxifen interactions Steady state concentrations about 300ng ml are achieved after four weeks treatment with 40mg daily