“The purpose of this review is to identify emerging or new psychoactive substances (nps) by undertaking an online survey of the uk nps market and to gather any data from online drug forums and published literature. drugs from four main classes of nps were identified: psychostimulants, dissociative anaesthetics, hallucinogens (phenylalkylamine-based and lysergamide-based materials) and finally benzodiazepines. for inclusion in the review, the ‘user reviewers’ on drugs forums were selected based on whether or not the particular nps of interest was used alone or in combination. nps that were used alone were considered. each of the classes contained drugs that are modelled on existing illegal materials and will be covered by the uk new psychoactive substances bill in 2016.”

“Novel psychoactive substances are newly used designer drugs (‘internet drugs’, ‘research chemicals’, ‘legal highs’) potentially posing similar health risks to classic illicit substances. chemically, many novel psychoactive substances can be classified as phenethylamines, amphetamines, synthetic cathinones, piperazines, pipradrols/piperidines, aminoindanes benzofurans, and tryptamines. pharmacologically, these substances interact with various monoaminergic targets. typically, stimulants inhibit the transport of dopamine and noradrenaline (pipradrols, pyrovalerone cathinones) or induce the release of these monoamines (amphetamines and methamphetamine-like cathinones), entactogens predominantly enhance serotonin release (phenylpiperazines, aminoindanes, para-substituted amphetamines, and mdma-like cathinones) similar to mdma (ecstasy), and hallucinogens (tryptamines, hallucinogenic phenethylamines) are direct agonists at serotonergic 5-ht2a receptors. synthetic cannabinoids are another group of novel substances which all act as agonists at the cannabinoid cb1 receptor similar to thc but are chemically diverse. in particular, the relative serotonergic vs dopaminergic activity (determined by the dopamine/serotonin transporter inhibition ratio in vitro) can be helpful to predict the desired psychotropic but also the toxic effects of novel substances as well as their potential for addiction. although the use of novel psychoactive substances mostly produces minor or moderate poisonings, serious complications occur. serotonergic drugs (entactogens and hallucinogens) are associated with acute serotonin syndrome, hyperthermia, seizures, and hyponatremia. dopaminergic drugs are highly addictive and acute toxicity includes prolonged stimulation, insomnia, agitation, and psychosis. agitation, anxiety, paranoia, hypertension, and rarely myocardial infarction and renal failure are seen with synthetic cannabinoids. treatment is supportive.”

“The regulation of new psychoactive substances (nps) has confounded governments throughout the western world. in 2014 the uk government convened an nps review expert panel to consider a range of approaches. ultimately the panel recommended that the government ban all new psychoactive drugs and allow only psychoactive substances specifically exempted, such as alcohol, tobacco and those allowed as medicines. the government introduced the psychoactive substances bill (psb) in response to that recommendation. passed in 2016, the bill has attracted a torrent of criticism from scientists and experts. the bill could be improved with revision, but the problems of the total ban, as envisioned by the psb, with respect to the nps, may be inherent: (1) defining psychoactivity is conceptually fraught, with great consequence for the scope of the prohibition; (2) operationalizing psychoactivity as a usable concept for legal control purposes is extremely difficult, perhaps impossible; and (3) the detachment of penalties for violating a total ban from establishing the harmfulness of a substance is normatively troubling. given the uncertainties about the effects of a total ban, it is appropriate at this time for other governments to assess more fully the nature of the nps problem, and the potential control approaches.”