Α-PHiP

α-Pyrrolidinoisohexanophenone (mainly known as A-PiHP or α-PiHP) is a stimulant drug of the cathinone class that has been sold online as a designer drug. It is a positional isomer of pyrovalerone, with the methyl group shifted from the 4-position of the aromatic ring to the 4-position of the acyl chain. In a classic 2006 study of pyrrolidinyl cathinone derivatives by Meltzer et al. at Organix, the alpha-isobutyl derivative of pyrovalerone, O-2494, was found to have the highest potency in vitro as an inhibitor of the dopamine transporter of the alpha substituted derivatives tested. α-PiHP acts as a norepinephrine–dopamine reuptake inhibitor. Compared to α-PVP and α-PHP, α-PiHP displays a higher selectivity for the dopamine transporter. Similar to other cathinones, use of α-PiHP can result in compulsive redosing, addiction, anxiety, paranoia, and psychosis. In July 2016 α-PHiP was first identified as a designer drug when it was reported to the EMCDDA by a forensic laboratory in Slovenia.