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Clinical Toxicity of the Designer “Party Pills” (Piperazine Derivatives)

Three Part Question

In [adult patients] presenting to the ED with [acute exposure to designer “party pills” (piperazine derivatives)], what are the [clinical features associated with significant morbidity and mortality]?

Clinical Scenario

An 30-year-old female is brought to your Emergency Department by ambulance with a chief complaint of drug overdose. The patient has intermittent tonic-clonic seizure activity and decreased responsiveness. In her pocket, you find several tablets later identified as party pills (or piperazine derivatives). As she is admitted to the hospital, you wonder what her prognosis will be.

Search Strategy

Medline 1946-5/13 using OVID interface, Cochrane Library (2013), PubMed clinical queries.

[piperazines/poisoning OR piperazines /toxicity]. Limit to English language, humans

Search Outcome

149 papers were identified; case-series that presented crude data and retrospective studies were excluded. Two clinical trials were found that were relevant to the clinical question.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Gee P, Gilbert M, Richardson S, Moore G, Paterson S, Graham P
New Zealand
April 2005-July 2007; 178 presentations of 156 patients with BZP toxicity, 69% with co-ingestions, most commonly ethanol;BZP serum levels drawn in 96prospective cohort Symptoms of BZP toxicity; plasma BZP level correlation with seizure incidence; affect of co-ingestion with ethanol on seizure frequency or the incidence of other adverse side effectsAdverse effects include confusion, agitation, vomiting, anxiety, palpitations. Higher plasma levels of BZP are associated with increased incidence of seizures. Co-ingestion with ethanol has a negative association with seizure frequency, but is positively associated with an increased risk of confusion, agitation, and palpitations.1) This is the largest cohort of BZP users studied in a clinical setting, however, a larger sample size would have added further power to the analysis 2) Patients self reported the number of pills taken and co-ingestants used, creating recall bias 3) Plasma BZP levels were not taken at a consistent time after ingestion
Gee P, Richardson S, Woltersdorf W, Moore G
New Zealand
April 2005-Sept 2005, Patients presenting to the emergency department after ingesting herbal party pills containing 1-benzylpiperazine (BZP)prospective cohort Patterns of human toxicity related to the use of 1- (BZP)-based herbal party pills61 patients presented on 80 occasions. Average pills ingested for patients with adverse effects were 4.5. Mild to moderate toxicity: insomnia, anxiety, nausea, vomiting, palpitations, dystonia, and urinary retension. Seizures in 15. Life threatening toxicity in 2 patients, with status epilepticus and severe respiratory and metabolic acidosis.This study was small, with an n=61.

Editor Comment


Clinical Bottom Line

BZP(benzyl-piperizine)-derivatives, are currently being used inplace of other amphetamine derivatives like MDMAs, as they are a legal alternative. The most common clinical side effects of BZP-containing designer party pills include confusion, agitation, vomiting, anxiety, and palpiations. Seizures are also known to occur, and can be seen with increasing plasma levels of BZP, but are less likely if ethanol has been co-ingested.


  1. Gee P, Gilbert M, Richardson S, Moore G, Paterson S, Graham P Toxicity from the recreational use of 1-benzylpiperazine Clin Toxicol (Phila) 2008; 46(9):802-7
  2. Gee P, Richardson S, Woltersdorf W, Moore G Toxic effects of BZP-based herbal party pills in humans: aprospective study in Christchurch, New Zealand New Zealand Medical Journal 2005; 118(1227):U1784