In study @ , the decrease in the mean -LSB- standard deviation -RSB- testosterone concentration from baseline to endpoint for male patients receiving tapentadol ER ( @ mg , -@ -LSB- @ -RSB- nmol/L ; @ mg , -@ -LSB- @ -RSB- nmol/L ) was numerically smaller compared to oxycodone CR ( @ mg , -@ -LSB- @ -RSB- nmol/L ) , but higher compared to placebo ( -@ -LSB- @ -RSB- nmol/L ) .