Aim: This study describes the demographics and symptoms of patients, who presented to the Emergency Department (ED) in Christchurch, New Zealand, with toxicity from 1-benzylpiperazine (BZP)-based "party pills." BZP use has become widespread among the 16- to 30-year age group in New Zealand. This study explores the relationship between plasma BZP level and adverse effects experienced by users. The influence of ethanol co-ingestion was also studied.
Methods: From 1 April 2005 to 1 July 2007, all BZP-related presentations to the ED were captured on a prospective data sheet. Patients were recruited to obtain plasma BZP levels, and these were correlated with the incidence of seizures and other symptoms. Coexistent ethanol use was also correlated with the frequency of seizures and other common BZP-induced symptoms.
Results: In total 178 presentations with BZP toxicity were recorded. BZP levels were measured in 96. Sixty-nine percent of patients co-ingested other substances, with the most common substance being ethanol. In patients who ingested BZP alone, increased plasma BZP levels were associated with increased seizure frequency. Ethanol co-ingestion reduced the incidence of seizures, but significantly increased the likelihood of confusion and agitation.
Conclusions: Adverse effects from BZP commonly include confusion, agitation, vomiting, anxiety, and palpitations. There is strong evidence that higher plasma levels of BZP are associated with an increased incidence of seizures. Co-ingestion of ethanol increases the likelihood of common and distressing BZP-induced symptoms but reduces the incidence of BZP seizures.