Helena Maria Teixeira

Cannabinoids are part of the most popular group of illicit substances in the Western world. The word “cannabinoid” refers to any chemical substance, regardless of structure or origin, that binds to the body’s cannabinoid receptors and that has effects similar to those produced by the Cannabis plant. Regarding their origin, cannabinoids can be classified into endocannabinoids, phytocannabinoids and synthetic cannabinoids. The behavioral and physiological effects of cannabinoids have received particular attention over the last few decades, including sensations of euphoria, relaxation and loss of concentration, with their repeated use being associated with short and long-term side effects, including respiratory and cardiovascular disorders, cognitive changes, psychoses, schizophrenia and mood disorders. On the other hand, recent investigations have proposed a promising therapeutic potential of cannabinoid-based drugs for a wide range of medical situations, including neurological and psychiatric disorders, among other indications. The growing popularity in the use of cannabinoid-based compounds, both for recreational and therapeutic purposes, has been accompanied by an equally continuous and growing evolution of knowledge regarding their potential harmful and beneficial effects. However, there are several open questions and challenges to be answered, which require more and better investigations. This article’s main objectives are: i) to understand the importance of the action of cannabinoids in humans; ii) identify the different types of cannabinoids that exist and understand the differences in their action; iii) distinguish the legislative framework for cannabinoid consumption; iv) identify the possible adverse effects of cannabinoid consumption, as well as their potential benefits; v) know the existing medical-scientific evidence in terms of therapeutic potential, particularly in relation to aspects of safety and efficacy; vi) encourage critical thinking about the recreational consumption and therapeutic use of cannabinoids, based both on currently available evidence and gaps in knowledge.

The innovation of the new psychoactive substances (NPS) market requires the rapid identification of new substances that can be a risk to public health, in order to reduce the damage from their use. Twelve seized products suspected to contain illicit substances were analyzed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), gas chromatography coupled to mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). Synthetic cathinones (SCat) were found in all products, either as a single component or in mixtures. Infrared spectra of all products were consistent with the molecular structure of SCat, showing an intense absorption band at 1700–1674 cm⁻¹, corresponding to the carbonyl stretching, a medium/strong peak at 1605–1580 cm⁻¹, indicating stretching vibrations in the aromatic ring (C=C) and bands with relative low intensity at frequencies near 2700–2400 cm⁻¹, corresponding to an amine salt. It was possible to identify a total of eight cathinone derivatives by GC-MS and NMR analysis: 4′-methyl-α-pyrrolidinohexanophenone (MPHP), α-pyrrolidinohexanophenone (α-PHP), 3-fluoromethcathinone (3-FMC), methedrone, methylone, buphedrone, N-ethylcathinone, and pentedrone. Among the adulterants found in these samples, caffeine was the most frequently detected substance, followed by ethylphenidate. These results highlight the prevalence of SCat in seized materials of the Portuguese market. Reference standards are usually required for confirmation, but when reference materials are not available, the combination of complementary techniques is fundamental for a rapid and an unequivocal identification of such substances.

This paper reports, for the first time, the development of a modified Quick, Easy, Cheap Effective, Rugged and Safe (QuEChERS) combined with a dispersive SPE (d-SPE) based clean-up procedure as a new and powerful strategy for the simultaneous and efficient isolation of two different antidepressants, fluoxetine and clomipramine, and their active metabolites in human urine samples. A univariate experimental design with four independent variables such as sample volume, extraction solvent, buffered salts and clean-up step, was performed and used to investigate the effect of process variables on the extraction efficiency. Good linearity was achieved at the studied concentration range (0.1–5.0 µg mL⁻¹), with correlation coefficients (R²) higher than 0.9961. Low detection limits, ranging between 0.060 and 0.092 μg mL⁻¹ were obtained for all analytes, whereas the lowest quantification limit was 0.1 μg mL⁻¹, corresponding to the lowest concentration of the standard curve. The method also showed good results for accuracy, with values ranging from 91% to 105%. Intra- and inter-day precision, expressed as the relative standard deviation (RSD), were also satisfactory (−1. In order to evaluate the proposed method for clinical use, the QuEChERS/UHPLC-PDA method was applied to analysis of 12 urine samples from depressed patients.

Gamma-hydroxybutyric acid (GHB) is an endogenous compound which has a story of clinical use and illicit abuse since the 1960’s. The possibility to use a multi-sample approach for GHB evaluation, including whole blood and hair, to better characterize a forensic toxicology case and evaluate a possible causal association with the death is an exciting up-to-date issue. In addition, its post-mortem behaviour, namely regarding degradation and metabolism, has been increasingly investigated as a putative biomarker for post-mortem interval (PMI) estimation. Thus, in order to contribute to clarification of this specific aspect, whole blood and hair post-mortem GHB levels were evaluated in 32 real cases with previous information on death and autopsy data. The results obtained suggest that the PMI (until 5 days between death and sampling) influences GHB whole blood concentration, but not GHB levels in hair samples. No differences were encountered for the other parameters evaluated, including age, gender, cause of death and presence or absence of substances. This study brings new insights regarding the usefulness of GHB levels in forensic toxicology, which might be further strengthened with larger, but comparable, studies from other laboratories and institutions in the context of legal medicine.