The objectives of this publication are to @ ) evaluate the effects of tapentadol ( NUCYNTA and NUCYNTA extended release -LSB- ER -RSB- ) on sex hormone concentrations in healthy male volunteers ( vs placebo and morphine ) and patients with osteoarthritis ( vs placebo and oxycodone ) , and @ ) present a mechanistic hypothesis explaining how the combined MOR agonist and NRI activities of tapentadol may result in less impact on androgen concentrations .