In recent years there has been a proliferation of ‘legal highs’ or ‘designer drugs’. These are compounds designed purposefully to be legal alternatives to prominent substances of abuse. Trends of use are difficult to determine. The data consist principally of case reports, examination of online fora and advertising sites and surveys of select populations, such as respondents to magazine questionnaires or patrons of specific bars and clubs.

We have observed that data from national poison control centers (PCC) suggest that legislation banning specific legal highs correlates with a drastic reduction of PCC contacts.

Synthetic cathinones, known more commonly as ‘bath salts’ in the United States, are a class of psychostimulants differing structurally from amphetamines by only an additional ketone [1]. On 21 October 2011 the US Drug Enforcement Agency placed a temporary federal ban on a number of bath salt compounds [1]. Reaching a high of 744 calls in June 2011, the American Association of Poison Control Centers (AAPCC) reported a decline in national PCC calls beginning in July 2011 (678) and decreasing markedly in October 2011 (400). This trend continued to December 2011 (223). Save for a brief increase in June–July of 2012, the declining trend has continued to the present, with 84 PCC calls in February 2012 representing an 89% reduction in just 8 months [2].

A strikingly similar trend was observed in the United Kingdom with the cathinone mephedrone, known popularly as ‘meow meow’. Following a high of approximately 120 contacts to the National Poisons Information Service (NPIS) in March 2010 and an increasing trend, the ban in April 2010 coincided with fewer than half the number of contacts and a prompt decrease to no more than 20 monthly calls sustained to March 2012 [3].

Methoxetamine, a ketamine analogue, was banned in the United Kingdom in April 2012 [4]. While the total number of national PCC calls was small (n = 47), nevertheless a similar decrease was observed. Comparing the 3-month period immediately prior to the ban to that immediately following it, telephone enquiries decreased from 15 to three, reflecting an 80% decrease. This pattern was also reflected in TOXBASE, the primary clinical toxicology database of the NPIS, allowing registered health professional access to information on specific substances. Accesses declined from 151 in the 3 months prior to the ban to 32 in the subsequent 3 months, a reduction of 79%.

Admittedly, there are limitations to inferring population use patterns from poison control data. Requests for telephone advice by clinicians is generally sought only in more severe cases or when unfamiliar with the substance. Further, fear of prosecution following change of legal status may deter patients from presenting for medical care [4].

Nevertheless, the recurrent pattern observed above in three separate instances of immediate and drastic decreases in PCC contacts following the banning of legal highs is strongly suggestive of similar decreases in usage in the general population.

Declarations of interest

None. The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Air Force, the Department of the Navy, the Department of Defense or the US Government.


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