Global health. The current scenario and future perspectives

209 they buy a dose of base paste? In practice, under the same name for an illegal substance, there are multiple options for that substance. For example, base paste without caffeine, base paste with low percentage of caffeine, base paste with high percentage of caffeine. But since caffeine is not the only adulterant used, we can imagine different combinations of drugs sold under one name - in this case, base paste - and these combinations can certainly be associated with different health risks for users, that are unknown to them. Adulterants are substances that have effects similar to the drug itself. Diluents are also added; these are mainly (but not exclusively) added to increase the volume. We will focus on adulterants here. There are several examples in the region: first and foremost we can mention a systematic review on this topic published by OID/CICAD in 2019: Drug Adulterants and Their Effects on the Health of Users: A Critical Review (CICAD 2019a). This publication provides information about main adulterants used in different illicit substances. For instance, cocaine (hydrochloride and base), ecstasy and heroin frequently contain caffeine, fenacetin and local anesthetics (such as benzocaine, lidocaine and procaine) as adulterants; levamisole is used as an adulterant in cocaine and heroin production; fentanyl and its derivatives are used as adulterants in cocaine, heroin and LSD. In Canada, a cross-sectional survey and urine analysis study found that among those who tested positive for fentanyl or analogues (in urine), 36% in British Columbia and over 90% in Montreal did not report having consumed fentanyl (in the survey), which suggests unintentional use or unknown exposure to this drug. As mentioned earlier, one of the main adulterants is caffeine and it is important to highlight studies by Galvalisi et al. (2016) and Schwarzkopf et al. (2018) that analyzed the effect of caffeine as an adulterant in cocaine base paste and its impact on the pulmonary inhalation route, which demonstrates its additive stimulating effect with the active ingredient; i.e., caffeine increases the stimulant and addictive effects of cocaine. The above is just a brief summary associated with the problem of adulterants in illicit substance production. The adulteration of psychoactive substances is a fact; it exists and is inherent to the distribution and commercialization process of illicit substances, which can have very negative consequences for consumer health. Methodological and technical aspects are to be studied to analyze the characterization of substances circulating in the market - these should be standardized to produce systematic information so that users of illegal substances can be informed about their health risks. Transferring this information to consumers is essential so they are aware of (currently unknown) damage caused by these substances, allowing them to make an informed - or at least less arbitrary - decision on whether or not to consume a particular substance. However, it is also important to note that unfortunately, this aspect of illegal substances is rarely discussed. It is overlooked and discussions about drugs continue as if each one were a homogeneous substance with uniform and known