Subjective effects in humans following administration of party pill drugs BZP and TFMPP alone and in combination

Abstract

The use of piperazine derivatives, colloquially named 'party pills', has been escalating in New Zealand and worldwide since their introduction in the 1990s. Benzylpiperazine (BZP) is often used alone, or can be combined with trifluoromethylphenylpiperazine (TFMPP). Taken together as an oral dose, they have been reported to produce effects similar to 3, 4-methylenedioxymethamphetamine (MDMA). While the pharmacokinetic data have recently been published, little research has been conducted on the subjective effects of these piperazines on humans. This paper outlines the subjective effects observed following oral doses of BZP (200 mg) and TFMPP (60 mg) alone, or in combination (100/30 mg) compared to placebo. Participants were asked to comment on the subjective effects of each drug using three subjective rating scales-the Addiction Center Research Inventory (ARCI), the Profile of Mood States (POMS), and the Visual Analog Scales (VAS)-before and approximately 120 min after a single dose. BZP showed significant dexamphetamine-like stimulant effects, inducing euphoria, sociability, and drug liking, whereas TFMPP induced fewer stimulant-like effects and increased anxiety, via its serotonergic effects. The combination of BZP and TFMPP induced similar subjective effects, along with well-characterized dexamphetamine- and MDMA-like effects. These subjective data allow for obvious comparisons to be made between party pill drugs and other commonly known stimulants. However, despite estimates of over 20 million doses sold in New Zealand alone and increasing seizures by the Drug Enforcement Administration in the USA, there are no published cases of dependence worldwide. The long-term effects of regular party pill use are also unknown, and create the potential for future research.