This review summarizes the literature to date relating to pyrolysis and heated vapour ingestion of drugs of abuse. In this context, heating is referred to as smoking or pyrolysis, but these are generic descriptors that encompass numerous methods of vapour generation and inhalation. Depending on the amount of drug used, diluents and contaminants present, heating conditions, and the oxidative/reductive environment, many thermal decomposition products can be formed. In addition to the recognized hazard of rapid onset of pharmacological effects of the parent drug, thermal decomposition products may be pharmacologically active as well as acutely/chronically toxic. For example, several published reports have linked heroin smoking to a form of brain encephalopathy and to the development of movement disorders. Early qualitative studies focusing on the thermal decomposition of drugs have evolved into more complex investigations employing mass spectral identification, confirmation, and elucidation of formation mechanism. In most cases, thermal decomposition begins with cleavage of the weakest bond (often C-N) to generate free radicals that then form the most stable sterically favoured products. Several reports of rearrangements at higher temperatures have been identified and hint at an underlying complexity that arises from the variety of smoking methods and conditions. Given that many designer drugs such as synthetic cannabinoids are ingested primarily through smoking, this issue has taken on new importance.

Since the introduction of herbal incense products into the illicit drug market, one of the most concerning factors has been the uncertainty regarding their health effects. Side effects such as anxiety/agitation, increased heartbeat, hallucinations, and suicidal tendencies are commonly reported with the use of products containing synthetic cannabinoid. However, a largely unknown toxicity and pharmacology is still associated with synthetic cannabinoids and long-term health effects have yet to be discussed. Prior scientific studies have not focused on the big-picture in terms of the pyrolysis of traditional drugs of abuse that are smoked or the relatively new synthetic cannabinoids. Numerous agencies and statistics have reported the number of health-related incidents regarding the use of synthetic cannabinoids, but there has yet to be peer-reviewed reports seeking to understand what caused these health effects. Therefore, the purpose of this research was to investigate the pyrolytic fate of JWH-018, JWH-030, JWH-081, and UR-144 and the smaller components which comprise these synthetic cannabinoids. Studying a number of the most common components that comprise a large number of the synthetic cannabinoids allows for a broad-ranging, cost-effective dissemination of results. A comprehensive approach was taken for identifying the pyrolytic products observed with a series of indole and naphthalene containing compounds. In doing so, a baseline of pyrolytic products that can form was established and it was found that a number of polyaromatic hydrocarbons, heterocyclic amines, and other hazardous or potentially hazardous compounds were generated. Analysis of the synthetic cannabinoids in this study showed that known carcinogenic compounds and potentially harmful pyrolytic products, such as carbazole, naphthalene, and benz[a]anthracene, are generated during smoking. The synthetic cannabinoids JWH-071 and JWH-018 were also, respectively, identified as pyrolytic products of JWH-018 and JWH-081. Furthermore, a number of compounds that were not identified have been reported which may, like the additionally generated synthetic cannabinoids, also retain activity at the cannabinoid receptors. iii DEDICATION This work is dedicated to my two very important younger siblings, Brooke and Blaine. iv ACKNOWLEDGMENTS Graduate school is not a journey that you can make it through alone and as such there are a number of acknowledgements that need to be made.