Collapse, reported seizure—and an unexpected pill

Abstract

In May, 2006, on a Bank Holiday weekend, an 18-year-old woman presented to an inner-city London emergency department. She had been at a nightclub with friends and purchased tablets, which she understood to be Ecstasy or amfetamines, from a dealer. After ingesting fi ve tablets, she collapsed in the nightclub and appeared to have a seizure lasting 10 min. On arrival in the emergency department, she was agitated and had dilated pupils (8 mm), sinus tachycardia (156 bpm), and a blood pressure of 150/51 mm Hg. Her score on the Glasgow coma scale was 15 and she was apyrexial (35·9°C). She had no signifi cant past medical history and was on no regular medication. She was one of seven patients to attend the department that night with a similar presentation. We therefore considered it possible that she had taken a contaminated drug, or a substance not previously sold in the area; and we took a serum sample for analysis, in addition to treating the patient symptomatically with intravenous benzodiazepines (4 mg lorazepam followed by 15 mg diazepam). After 12 h, she was asymptomatic and discharged with advice to avoid recreational drugs. The serum sample was analysed by gas chromatography with mass-spectrometric detection (GCMS); 1-benzylpiperazine was detected at a concentration of 2·5 mg/L. Toxicological screening of the same serum sample did not detect the presence of other piperazines, other drugs, or ethanol. A tablet purchased by the patient (fi gure) was also analysed, and found to contain 1-benzylpiperazine. 1-benzylpiperazine is one of the piperazine family of drugs, initially developed as veterinary anthelmintic agents in the 1950s. Its chemical structure is similar to that of amfetamine. Piperazines are marketed in the UK, where they are legally available in shops and over the internet, as having similar eff ects to controlled recreational drugs; pills containing piperazines are known as “pep pills”. No reliable data are available on the consumption of piperazines in the UK, although one manufacturer claims that “over 20 million pills have been consumed in New Zealand with no deaths, or signifi cant lasting injuries”. However, in initial clinical trials of 1-benzylpiperazine, adverse eff ects similar to those of amfetamines were noted. A prospective study in New Zealand identifi ed adverse eff ects including nausea, vomiting, tachycardia, hypertension, anxiety, and agitation among 80 patients presenting to emergency departments after 1-benzylpiperazine ingestion. Seizures were reported in 15 (19%), at up to 8 h after ingestion. Three patients had potentially life-threatening recurrent seizures; ingestion of 1-benzylpiperazine by these patients was confi rmed by toxicological screening of their urine. Other potentially serious adverse eff ects included QTc prolongation (QTc duration 430–490 ms in 32 patients) and hyponatraemia (serum sodium concentration 118 mmol/L and serum osmolality 242 mmol/kg) in one patient. Clinicians should be aware of the potential presenting features of piperazine toxicity, particularly because commercially available urine toxicological screening kits for drugs of abuse may not detect piperazines. All patients with strongly suspected or reported ingestion of 1-benzylpiperazine should have an initial baseline ECG, to seek features of cardiotoxicity. They should be observed for up to 8 h after ingestion, because the onset of seizures can be delayed. Initial treatment should be based on the clinical presentation. Further management can require the advice of a clinical toxicologist.