Benzylpiperazine: a drug of abuse?

Molecular Imprinting of Benzylpiperazine: A Comparison of the Self-Assembly and Semi-Covalent Approaches

Molecularly imprinted polymers (MIPs) for benzylpiperazine (BZP, 1), an illicit designer drug, were developed by using both self-assembly and semi-covalent approaches. From an array of potential functional monomers (FMs) and using a combination of pre-synthetic interaction studies (by molecular modelling and NMR analysis) and binding assays, the highest performing self-assembly 1-MIPs were confirmed to result from methacrylic acid (7) as FM, ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) as crosslinkers and chloroform as the porogen and rebinding solvent at template (T): FM ratios of 1:1 and 1:2, giving imprinting factors (IF) 3 to 7. The semi-covalent 1-MIPs were designed using benzylpiperazine (4-vinylphenyl) carbamate (16) as the template-monomer adduct in combination with either EDGMA or TRIM. Our comparative analysis showed the semi-covalent polymers to have a stronger affinity for 1 (significantly lower K_d values and higher IFs) and faster uptake than the self-assembly systems. Both approaches have comparable cross-reactivity: marginal to low against cocaine (17) and morphine (18) and high against ephedrine (19) and phenylpiperazine (20). They also have comparable selectivity: highly selective towards 1 against 17, moderate against 18 and non-selective against 19. EGDMA-based self-assembly MIPs displayed a greater imprinting effect (higher IFs and NIP-to-MIP K_d ratios) than TRIM-based MIPs, while the TRIM-based semi-covalent MIP outperformed its EGDMA-based equivalent. By virtue of its modest selectivity against the test illicit drugs, 1-MIPs could potentially be used as a dummy MIP for the broad-based capture and enrichment of illicit drug blends for subsequent laboratory analysis.

A Review on the Arylpiperazine Derivatives as Potential Therapeutics for the Treatment of Various Neurological Disorders

Abstract:

Neurological disorders are disease conditions related to the neurons and central nervous system (CNS). Any kind of structural, electrical, biochemical and functional abnormalities in neurons can lead to various types of disorders like Alzheimer’s disease (AD), depression, Parkinson’s disease (PD), epilepsy, stroke, etc. Currently available medicines are symptomatic and do not treat the disease state. Thus, novel CNS active agents with the potential of complete treatment of an illness are highly desired. A range of small organic molecules are being explored as potential drug candidates for the cure of different neurological disorders. In this context, arylpiperazine has been found to be a versatile scaffold and indispensable pharmacophore in many CNS active agents. A number of molecules with arylpiperazine nucleus have been developed as potent leads for the treatment of AD, PD, depression and other disorders. The arylpiperazine nucleus can be optionally substituted at different chemical structures and offer flexibility for the synthesis of large number of derivatives. In the current review article, we have explored the role of various arylpiperazine containing scaffolds against different neurological disorders, including AD, PD, and depression. The structure-activity relationship studies were conducted for recognizing potent lead compounds. This review article may provide important clues on the structural requirements for the design and synthesis of effective molecules as curative agents for different neurological disorders.

Piperazine derivatives with central pharmacological activity used as therapeutic tools

Medicinal chemistry is a science applied to the search and discovery of new therapeutic agents for the treatment of various diseases. Therefore, promising structures have been identified; one of these structures is the piperazine moiety, a cyclic molecule containing two nitrogen atoms in positions 1 and 4 as well as four carbon atoms. Many piperazine derivatives have central pharmacological activity that mainly involves the activation of the monoamine pathway. Thus, piperazine derivatives have been the subject of research for many central therapeutic applications, including antipsychotic, antidepressant and anxiolytic applications. Benzylpiperazine is the prototype of piperazine derivatives; this substance is the main component of recreational drugs, partly due to its stimulant and euphoric effects. This paper describes some piperazine derivatives used therapeutically as antipsychotic (clozapine), antidepressant (vortioxetine) and anxiolytic (buspirone) drugs.

Using Social Listening Data to Monitor Misuse and Nonmedical Use of Bupropion: A Content Analysis

Background

The nonmedical use of pharmaceutical products has become a significant public health concern. Traditionally, the evaluation of nonmedical use has focused on controlled substances with addiction risk. Currently, there is no effective means of evaluating the nonmedical use of noncontrolled antidepressants.

Objective

Social listening, in the context of public health sometimes called infodemiology or infoveillance, is the process of identifying and assessing what is being said about a company, product, brand, or individual, within forms of electronic interactive media. The objectives of this study were (1) to determine whether content analysis of social listening data could be utilized to identify posts discussing potential misuse or nonmedical use of bupropion and two comparators, amitriptyline and venlafaxine, and (2) to describe and characterize these posts.

Methods

Social listening was performed on all publicly available posts cumulative through July 29, 2015, from two harm-reduction Web forums, Bluelight and Opiophile, which mentioned the study drugs. The acquired data were stripped of personally identifiable identification (PII). A set of generic, brand, and vernacular product names was used to identify product references in posts. Posts were obtained using natural language processing tools to identify vernacular references to drug misuse-related Preferred Terms from the English Medical Dictionary for Regulatory Activities (MedDRA) version 18 terminology. Posts were reviewed manually by coders, who extracted relevant details.

Results

A total of 7756 references to at least one of the study antidepressants were identified within posts gathered for this study. Of these posts, 668 (8.61%, 668/7756) referenced misuse or nonmedical use of the drug, with bupropion accounting for 438 (65.6%, 438/668). Of the 668 posts, nonmedical use was discouraged by 40.6% (178/438), 22% (22/100), and 18.5% (24/130) and encouraged by 12.3% (54/438), 10% (10/100), and 10.8% (14/130) for bupropion, amitriptyline, and venlafaxine, respectively. The most commonly reported desired effects were similar to stimulants with bupropion, sedatives with amitriptyline, and dissociatives with venlafaxine. The nasal route of administration was most frequently reported for bupropion, whereas the oral route was most frequently reported for amitriptyline and venlafaxine. Bupropion and venlafaxine were most commonly procured from health care providers, whereas amitriptyline was most commonly obtained or stolen from a third party. The Fleiss kappa for interrater agreement among 20 items with 7 categorical response options evaluated by all 11 raters was 0.448 (95% CI 0.421-0.457).

Conclusions

Social listening, conducted in collaboration with harm-reduction Web forums, offers a valuable new data source that can be used for monitoring nonmedical use of antidepressants. Additional work on the capabilities of social listening will help further delineate the benefits and limitations of this rapidly evolving data source.

Benzylpiperazine: "A messy drug"

Designer drugs are synthetic structural analogues/congeners of controlled substances with slightly modified chemical structures intended to mimic the pharmacological effects of known drugs of abuse so as to evade drug classification. Benzylpiperazine (BZP), a piperazine derivative, elevates synaptic dopamine and serotonin levels producing stimulatory and hallucinogenic effects, respectively, similar to the well-known drug of abuse, methylenedioxymethamphetamine (MDMA). Furthermore, BZP augments the release of norepinephrine by inhibiting presynaptic autoreceptors, therefore, BZP is a "messy drug" due to its multifaceted regulation of synaptic monoamine neurotransmitters. Initially, pharmaceutical companies used BZP as a therapeutic drug for the treatment of various disease states, but due to its contraindications and abuse potential it was withdrawn from the market. BZP imparts predominately sympathomimetic effects accompanied by serious cardiovascular implications. Addictive properties of BZP include behavioral sensitization, cross sensitization, conditioned place preference and repeated self-administration. Additional testing of piperazine derived drugs is needed due to a scarcity of toxicological data and widely abuse worldwide.

Nephrotoxic effects of common and emerging drugs of abuse

The kidneys can be injured in diverse ways by many drugs, both legal and illegal. Novel associations and descriptions of nephrotoxic effects of common and emerging drugs of abuse have appeared over the past several years. Anabolic androgenic steroids, illicitly used by athletes and others for decades to increase muscle mass and decrease body fat, are emerging as podocyte toxins given recent descriptions of severe forms of FSGS in long-term abusers. Synthetic cannabinoids, a new group of compounds with marijuana-like effects, recently became popular as recreational drugs and have been associated with an atypical form of AKI. 3,4-Methylenedioxymethamphetamine, commonly known as ecstasy, is a widely used synthetic recreational drug with mood-enhancing properties and a constellation of toxicities that can result in death. These toxic effects include hyperthermia, hypotonic hyponatremia due to its arginine vasopressin secretagogue-like effects, rhabdomyolysis, and cardiovascular collapse. Cocaine, a serotonin-norepinephrine-dopamine reuptake inhibitor that serves as an illegal stimulant, appetite suppressant, and anesthetic, also causes vasoconstriction and rhabdomyolysis. Recent adulteration of much of the world's supply of cocaine with levamisole, an antihelminthic agent with attributes similar to but distinct from those of cocaine, appears to have spawned a new type of ANCA-associated systemic vasculitis. This review discusses the nephrotoxic effects of these common and emerging drugs of abuse, of which both community and health care providers should become aware given their widespread abuse. Future investigation into pathogenetic mechanisms associated with these drugs is critical and may provide a window into ways to lessen and even prevent the nephrotoxic effects of these drugs of abuse and perhaps allow a deeper understanding of the nephrotoxicities themselves.

Benzylpiperazine-induced acute delirium in a patient with schizophrenia and an incidental temporal meningioma

Benzylpiperazine is a psychotropic compound that has been widely available until recently from licensed premises such as ‘head shops’. This report describes a case of a 48 year old man with schizophrenia who developed an acute delirium secondary to benzylpiperazine use, although he initially presented as a diagnostic conundrum. Investigation of his delirium unearthed a temporal meningioma which appears to be an incidental finding. This is the first documented case of delirium due to benzylpiperazine use. Benzylpiperazine has significant abuse potential and psychiatric complications. Its sale and possession have recently been made illegal in Ireland, which may limit its abuse in the future.

Estrogenic effects and their action mechanism of the major active components of party pill drugs

Benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) are commonly used constituents of party pill drugs. They are reported to induce psychoactive effects such as euphoria and provide effects similar with other illicit drugs such as methylenedioxymethamphetamine (MDMA). A great deal of evidence has proven that party pills, as alternatives for MDMA, exert harmful effects on users. However, their toxicological effects have not been fully understood and endocrine disruptive effects are still unknown. In this study, we identified estrogenic effects of BZP and TFMPP by using in vitro and in vivo assays. BZP and TFMPP stimulated cell proliferation in a dose-dependent manner, while co-treatment with tamoxifen and BZP or TFMPP showed a decrease of E(2)-induced cell proliferation. In an estrogen sensitive reporter gene assay, BZP and TFMPP significantly increased transcriptional activities of party pill drugs. In addition, ER-related genes, PR and pS2, were significantly stimulated by BZP and TFMPP. These results indicated that BZP and TFMPP could have estrogenic activities related to the ER-mediated pathway. Unlike the in vitro assay results, BZP and TFMPP did not show significant effects on weight increase in a rodent uterotrophic assay. However, further studies would be necessary to verify the estrogenic activities of BZP and TFMPP by a chronic exposure animal study.

Linking the pharmacological content of ecstasy tablets to the subjective experiences of drug users

RATIONALE

Most studies on the subjective effects of ecstasy are based on the assumption that the substance that was taken is 3,4-methylenedioxymethamphetamine (MDMA). However, many tablets sold as ecstasy contain other substances and MDMA in varying doses. So far, few attempts have been made to take this into account while assessing subjective effects.

OBJECTIVES

This study aims to link the pharmacological content of tablets sold as ecstasy to the subjective experiences reported by ecstasy users.

METHODS

Self-reported effects on ecstasy tablets were available from 5,786 drug users who handed in their tablets for chemical analysis at the Drug Information and Monitoring System (DIMS) in the Netherlands. Logistic regression was employed to link the pharmacological content of ecstasy tablets to the self-reported subjective effects and compare effects with MDMA to other substances present.

RESULTS

MDMA showed a strong association with desirable subjective effects, unparalleled by any other psychoactive substance. However, the association of MDMA was dose-dependent, with higher doses (>120 mg/tablet) likely to evoke more adverse effects. The novel psychostimulants mephedrone and p-fluoroamphetamine were considered relatively desirable, whereas meta-chlorophenylpiperazine (mCPP) and p-methoxymethamphetamine (PMMA) were strongly associated with adverse subjective effects. Also, 3,4-methylene-dioxyamphetamine (MDA) and benzylpiperazine (BZP) were not appreciated as replacement for MDMA.

CONCLUSION

Linking the pharmacological content of ecstasy sold on the street to subjective experiences contributes to a better understanding of the wide range of subjective effects ascribed to ecstasy and provides a strong rationale for the prolonged endurance of MDMA as the key ingredient of the ecstasy market.

The clinical toxicology of the designer "party pills" benzylpiperazine and trifluoromethylphenylpiperazine

INTRODUCTION

Benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) are synthetic phenylpiperazine analogues. BZP was investigated as a potential antidepressant in the early 1970s but was found unsuitable for this purpose. More recently, BZP and TFMPP have been used as substitutes for amfetamine-derived designer drugs. They were legally available in a number of countries, particularly in New Zealand, and were marketed as party pills, but are now more heavily regulated. This article will review the mechanisms of toxicity, toxicokinetics, clinical features, diagnosis, and management of poisoning due to BZP and TFMPP.

METHODS

OVID MEDLINE and ISI Web of Science were searched systematically for studies on BZP and TFMPP and the bibliographies of identified articles were screened for additional relevant studies including nonindexed reports. Nonpeer-reviewed sources were also accessed. In all, 179 papers excluding duplicates were identified and 74 were considered relevant.

MECHANISMS OF ACTION

BZP and TFMPP have stimulant and amfetamine-like properties. They enhance the release of catecholamines, particularly of dopamine, from sympathetic nerve terminals, increasing intra-synaptic concentrations. The resulting elevated intra-synaptic monoamine concentrations cause increased activation of both central and peripheral α- and β-adrenergic postsynaptic receptors. BZP has primarily dopaminergic and noradrenergic action while TFMPP has a more direct serotonin agonist activity.

TOXICOKINETICS

There is limited information on the kinetics of these drugs. Following ingestion, peak plasma concentrations are reached after 60 to 90 min. Both drugs would be expected to cross the blood brain barrier and they are metabolized mainly by hydroxylation and N-dealkylation catalyzed by cytochrome P450 and catechol-o-methyl transferase enzymes. In humans, only small amounts of both BZP and TFMPP are excreted in the urine, suggesting a low bioavailability. The serum half-lives of BZP and TFMPP are relatively short with elimination being essentially complete in 44 h for BZP and 24 h for TFMPP.

CLINICAL FEATURES

These compounds can cause harmful effects when taken recreationally. Commonly reported features include palpitations, agitation, anxiety, confusion, dizziness, headache, tremor, mydriasis, insomnia, urine retention, and vomiting. Seizures are induced in some patients even at low doses. Severe multiorgan toxicity has been reported, though fatalities have not been recorded conclusively.

MANAGEMENT

Supportive care including the termination of seizures is paramount, with relief of symptoms usually being provided by benzodiazepines alone.

CONCLUSIONS

BZP and TFMP can cause sympathomimetic effects in the intoxicated patient. Appropriate, symptom-directed supportive care should ensure a good recovery.

Determining the subjective and physiological effects of BZP combined with TFMPP in human males

RATIONALE

‘Party Pills’ containing benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) have been used in a recreational context since the 1990s and, prior to April 2008, were legally available in New Zealand. Taken together, they have been reported to produce a ‘high’ similar to that produced by 3,4-methylenedioxymethamphetamine (MDMA).

OBJECTIVES

There has been little research on the subjective effects of piperazines in humans. The purpose of this study is to further investigate the subjective and physiological responses following an oral dose of BZP combined with TFMPP in males.

METHODS

In a randomised, double-blind, placebo-controlled study the subjective and physiological effects of BZP/TFMPP were investigated in 36 healthy, non-smoking males (mean age 22 ± 4 years). Participants were tested before and approximately 120 min after administration of a single dose of placebo (n = 16) or 100/30 mg BZP/TFMPP (n = 20). Participants were required to comment on the subjective effects using three rating scales—the Addiction Research Centre Inventory (ARCI), the Visual Analogue Scale (VAS) and the Profile of Mood States (POMS). Participants' blood pressure, heart rate and body temperature were also measured.

RESULTS

Statistical analysis using repeated-measures analysis of variance (ANOVA) and planned comparisons revealed that BZP/TFMPP significantly increases blood pressure and heart rate (p < 0.05). Likewise, the subjective rating scales revealed that BZP/TFMPP has significant dexamphetamine-like effects, increases dysphoria and feelings of self-confidence (p < 0.05).

CONCLUSION

These physiological and subjective data reflect clear similarities between the effects of BZP/TFMPP and commonly known stimulants such as dexamphetamine and MDMA.

BZP-party pills: a review of research on benzylpiperazine as a recreational drug

BACKGROUND

BZP-party pills are yet another 'designer drug' which mimics the stimulant qualities of amphetamines and MDMA/Ecstasy. As legal markets for the substance have developed in the last decade (especially amongst young people) so has public and governmental concern.

METHODS

This article provides a summary of the available international research on benzylpiperazine (BZP) and its popular use in the compound form known as 'party pills'. Through performing an analysis of the available medical and social scientific literature, the review outlines current knowledge on the compound, the prevalence of usage of BZP-party pills, as well as the associated harms, risks and rationales for use of the drug.

RESULTS

Despite moves towards legislative control of BZP-party pills, the evidence presented suggests limited social and health harms associated with the drug, although research on long term effects is a significant gap in the literature. It also remains inconclusive as to whether BZP-party pills act as a 'gateway' to illegal drugs or, conversely, play a role in harm reduction with illegal drug users turning to legal alternatives; there is some evidence for both positions.

CONCLUSION

With increasing controls of BZP-party pills, and with the increasing numbers of 'legal highs' and new designer drugs on the market, we conclude that new legal alternatives will continue to surface to replace the drug in the future. Considering a harm reduction approach to drug taking, it is suggested that policy makers consider the creation of a legal holding category which restricts and regulates the market in legal highs whilst the social and health harms associated with each drug can be thoroughly investigated.

Pharmacologic neuroimaging of the ontogeny of dopamine receptor function

Characterization of the ontogeny of the cerebral dopaminergic system is crucial for gaining a greater understanding of normal brain development and its alterations in response to drugs of abuse or conditions such as attention-deficit hyperactivity disorder. Pharmacological MRI (phMRI) was used to determine the response to dopamine transporter (DAT) blockers cocaine and methylphenidate (MPH), the dopamine releaser D-amphetamine (AMPH), the selective D1 agonist dihydrexidine, and the D2/D3 agonist quinpirole in young (<30 days old) and adult (>60 days old) rats. In adult rats, cocaine (0.5 mg/kg i.v.) or MPH (2 mg/kg) induced primarily positive cerebral blood volume (rCBV) changes in the dopaminergic circuitry, but negative rCBV changes in the young animals. Microdialysis measurements in the striatum showed that young rats have a smaller increase in extracellular dopamine in response to cocaine than adults. The young rats showed little rCBV response to the selective D1 agonist dihydrexidine in contrast to robust rCBV increases observed in the adults, whereas there was a similar negative rCBV response in the young and adult rats to the D2 agonist quinpirole. We also performed a meta-analysis of literature data on the development of D1 and D2 receptors and the DAT. These data suggest a predominance of D2-like over D1-like function between 20 and 30 days of age. These combined results suggested that the dopamine D1 receptor is functionally inhibited at young age.

Content of ecstasy in the Netherlands: 1993-2008

AIMS

The present paper outlines the results of analyses carried out on the content of tablets sold as ecstasy, collected in the Netherlands by the Drugs Information Monitoring System (DIMS) from January 1993 to December 2008.

METHODS

During a period of 16 years, the DIMS analysed the content of 33 006 tablets sold as ecstasy that were handed in by numerous individual (potential) substance users. The DIMS results were compared with the results from various seized tablets to determine whether the DIMS is a monitor of the ecstasy consumer market.

RESULTS

The DIMS system appears to be a market monitor that gives an accurate reflection of what is actually available on the hidden Dutch ecstasy market. During 16 years of monitoring, the purity [tablets containing only 3,4-methylenedioxymethamphetamine (MDMA)] was lowest around 1997. During this time-period many tablets contained other substances in addition to or instead of MDMA [e.g. 3,4-methylene-dioxyamphetamine (MDA), 3,4-methylene-dioxyethylamphetamine (MDEA) and N-methyl-a-(1,3-benzodixol-5-yl)-2-butamine (MBDB), amphetamine and caffeine]. From 1998 to 2008, the number of high-dose tablets (> or =106 mg MDMA per tablet) gradually increased. The same holds true for the proportion of tablets that contained only MDMA, reaching the highest levels in 2000 and 2004. After 2004, the purity of ecstasy tablets decreased again, caused mainly by a growing proportion of tablets containing meta-chlorophenylpiperazine (mCPP).

CONCLUSIONS

The DIMS results provide valuable qualitative information on the content of ecstasy tablets in the Netherlands, and its changes throughout the years. Moreover, the results were used for national and international risk assessments and important warning and prevention activities.