a-Pyrrolidinoisohexanophenone (IUPAC chemical name: 4-Methyl-1-phenyl-2- (pyrrolidin-1-yl)pentan-1-one), also known as a-PiHP, is a synthetic cathinone. It has been described as an off-white solid, a white powder and a crystalline solid.
WHO review history
a-PiHP has not been formally reviewed by WHO and is not currently under international control. Information was brought to the attention of WHO that this substance is manufactured clandestinely, poses a risk to public health and has no recognized therapeutic use.
Similarity to known substances and effects on the central nervous system
a-PiHP is an isomer of a-PHP, which is controlled under Schedule II of the Convention on Psychotropic Substances of 1971. Laboratory studies suggest that a-PiHP can inhibit the uptake of dopamine and norepinephrine more potently than substances with known abuse potential, including methcathinone, cocaine and methamphetamine. Studies in animals have shown that a-PiHP is a psychomotor stimulant, with effects comparable to those of cocaine and methamphetamine.
Online self-reports by people who use a-PiHP describe stimulant effects similar to those of a-PVP and a-PHP.
No controlled studies of the dependence potential of a-PiHP in animals or humans have been reported. In view of its actions and effects on the central nervous system, it would be expected to produce dependence similarly to other psychostimulants such as methamphetamine.
Actual abuse and/or evidence of likelihood of abuse
Studies in animals predictive of abuse liability indicate that a-PiHP produces effects similar to those of methamphetamine and cocaine. No controlled studies of the abuse potential of a-PiHP in humans have been reported.
Seizures of a-PiHP have been described in multiple countries in three regions. a-PiHP has been identified in a number of serious adverse events and drug-related deaths. As it is usually detected with other substances, including opioids and benzodiazepines, the role of a-PiHP is unclear in some instances.
a-PiHP is not known to have any therapeutic use.
a-Pyrrolidinoisohexanophenone (IUPAC chemical name: 4-Methyl-1-phenyl- 2-(pyrrolidin-1-yl)pentan-1-one), also known as a-PiHP, is a synthetic cathinone with effects similar to those of other synthetic cathinones and other psychostimulants, such as methamphetamine, that are listed under Schedule II of the Convention on Psychotropic Substances of 1971. There is evidence that its abuse is likely to constitute a substantial public health and social problem. It has no known therapeutic use.
Recommendation: The Committee recommended that a-pyrrolidinoiso- hexanophenone (IUPAC chemical name: 4-methyl-1-phenyl-2-(pyrrolidin-1- yl)pentan-1-one), also known as a-PiHP, be added to Schedule II of the 1971 Convention on Psychotropic Substances.