title: The impact of the prohibition of benzylpiperazine (BZP) "legal highs" on the availability, price and strength of BZP in New Zealand.
abstract: BACKGROUND
  Legal highs containing benzylpiperazine (BZP) were widely sold in New Zealand until BZP was prohibited in 2008. We examined the impact the prohibition had on the availability and price of BZP over following years.
  
  
  METHODS
  Two national population surveys of BZP use were conducted in 2006 and 2009. Four annual targeted surveys of frequent drug users (FDU) were conducted from 2007-2010. Availability and price measures were obtained. Inflation-adjusted real retail prices were calculated. Other drug markets were monitored as quasi-controls.
  
  
  RESULTS
  The proportion of BZP users from the general population who considered the availability of BZP to be 'very easy' declined from 76% in 2006 to 21% in 2009. The proportion who thought BZP had become 'harder' to obtain increased from 5% in 2006 to 71% in 2009. The proportion who reported the price of BZP was 'higher' increased from 27% in 2006 to 51% in 2009. FDU who considered the availability of BZP to be 'very easy' declined from 98% in 2007 to 15% in 2008, and then increased to 42% by 2010. The real retail price of a BZP tablet increased from $9.86 in 2007 to $15.83 in 2010. The proportion who considered the price of BZP to be 'increasing' rose from 3% in 2007 to 47% in 2010.
  
  
  CONCLUSIONS
  The availability of BZP declined immediately following its prohibition. Availability recovered in subsequent years, but not to the pre-prohibition legal level. The price of BZP increased slowly over a number of years following the prohibition.
authors.affiliation: Social and Health Outcomes Research and Evaluation (SHORE), SHORE and Whariki Research Centre, School of Public Health, Massey University, PO Box 6137, Wellesley Street, Auckland 1141, New Zealand. Electronic address: c.wilkins@massey.ac.nz.
authors.forename: Chris
authors.initials: C
authors.lastname: Wilkins
authors.affiliation: Social and Health Outcomes Research and Evaluation (SHORE), SHORE and Whariki Research Centre, School of Public Health, Massey University, PO Box 6137, Wellesley Street, Auckland 1141, New Zealand.
authors.forename: Paul
authors.initials: P
authors.lastname: Sweetsur
authors.affiliation: Social and Health Outcomes Research and Evaluation (SHORE), SHORE and Whariki Research Centre, School of Public Health, Massey University, PO Box 6137, Wellesley Street, Auckland 1141, New Zealand.
authors.forename: Karl
authors.initials: K
authors.lastname: Parker
mesh_terms: D000293:Adolescent; D000328:Adult; D003625:Data Collection / Q000379:methods; D055030:Drug Users; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000737:chemistry / Q000191:economics*; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D010879:Piperazines / Q000737:chemistry / Q000191:economics*; D019966:Substance-Related Disorders / Q000191:economics* / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D013287:Illicit Drugs; C461488:N-benzylpiperazine; D010879:Piperazines
keywords: BZP; Illegal markets; Legal highs; New psychoactive substances; Prohibition