3-Hydroxyphencyclidine ( 3-HO-PCP) is a dissociative hallucinogen of the arylcyclohexylamine class related to phencyclidine (PCP) that has been sold online as a designer drug.
3-HO-PCP acts as a high-
affinity uncompetitive antagonist of the NMDA receptor via the dizocilpine (MK-801) site (K i = 30 nM).  It has much higher affinity than PCP for this site (K  i = 250 nM, for comparison; 8-fold difference). The drug also has high affinity for the  μ-opioid receptor (MOR) (K i = 39–60 nM),    the  κ-opioid receptor (KOR) (K i = 140 nM), and the  sigma σ (K 1 receptor i = 42 nM; IC = 19 nM), 50    whereas it has only low affinity for the  δ-opioid receptor (K i = 2,300 nM). The high affinity of 3-HO-PCP for  opioid receptors is unique among arylcyclohexylamines and is in contrast to PCP, which has only very low affinity for the MOR (K i = 11,000–26,000 nM; 282- to 433-fold difference) and the other opioid receptors (K i = 4,100 nM for the KOR and 73,000 nM for the DOR). 
Although it was hypothesized that 3-HO-PCP might be a
metabolite of PCP in humans, there is no evidence that this is the case. 
3-HO-PCP is an
arylcyclohexylamine. Close  analogues of 3-HO-PCP include PCP, 3-MeO-PCP, 4-MeO-PCP, 3-MeO-PCMo, and somewhat more distantly ketamine, methoxyketamine, 3-MeO-PCE, and methoxetamine.
Society and culture
3-HO-PCP is legal in Germany.
On October 18, 2012 the
Advisory Council on the Misuse of Drugs in the United Kingdom released a report about methoxetamine, saying that the "harms of methoxetamine are commensurate with Class B of the Misuse of Drugs Act (1971)", despite the fact that the act does not classify drugs based on harm. The report went on to suggest that all analogues of MXE should also become class B drugs and suggested a catch-all clause covering both existing and unresearched arylcyclohexamines, including 3-HO-PCP.
3-HO-PCP is a close
analogue of PCP. Hence, possession or distribution for use in humans could potentially be prosecuted under the Federal Analogue Act.
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