ile ▁ere ction , ▁the ▁latter ▁two ▁the ▁result ▁of ▁increased ▁ 5 - HT 2 C ▁activity ▁and ▁the ▁former ▁likely ▁via ▁ 5 - HT 3 ▁stim ulation . ▁ ▁In ▁comparison ▁studies , ▁m CP P ▁has ▁approximately ▁ 1 0 - fold ▁select ivity ▁for ▁the ▁human ▁ 5 - HT 2 C ▁re ceptor ▁over ▁the ▁human ▁ 5 - HT 2 A ▁and ▁ 5 - HT 2 B ▁re cept ors ▁( K i ▁= ▁ 3 . 4   n M ▁vs . ▁ 3 2 . 1 ▁and ▁ 2 8 . 8   n M ). ▁It ▁acts ▁as ▁a ▁partial ▁ag on ist ▁of ▁the ▁human ▁ 5 - HT 2 C ▁re ceptor ▁but ▁as ▁an ▁ant agon ist ▁of ▁the ▁human ▁ 5 - HT 2 A ▁and ▁ 5 - HT 2 B ▁re cept ors . ▁In ▁accord ance ▁with ▁its ▁lack ▁of ▁ag on ism ▁towards ▁the ▁human ▁ 5 - HT 2 A ▁re ceptor , ▁there ▁are ▁no ▁reports ▁that ▁m CP P ▁produces ▁hall uc in ogen ic ▁effects ▁in ▁humans . ▁ ▁Ph arm ac ok inet ics ▁m CP P ▁is ▁met abol ized ▁via ▁the ▁C Y P 2 D 6 ▁is o enz yme ▁by ▁hydro x yl ation ▁to ▁para - h ydro xy - m CP P ▁( p - OH - m CP P ). ▁Ca ution ▁should ▁be ▁exerc ised ▁in ▁cop res cri bing ▁in