Severe acute intoxication with yohimbine: Four simultaneous poisoning cases

The New Stealth Drug on the Street: A Narrative Review of Xylazine as a Street Drug

Xylazine is an alpha-adrenergic receptor agonist approved for use only in animals with a prescription from a veterinarian. It is a powerful sedative that is slowly infiltrating the recreational street drug scene and is often used by polysubstance abusers. Known as "tranq," it can be fatal, and xylazine-induced toxicity cannot be reversed with naloxone or nalmefene. Due to its vasoconstrictive effects, chronic use of xylazine is associated with necrotic skin lesions and general deterioration of health. Since xylazine is not approved for human use and is not scheduled as a controlled substance, there are no human studies to provide evidence of drug-drug interactions, lethal doses, or reversal protocols. Xylazine is available online without a prescription. Street drug users may take xylazine knowingly or unknowingly, as it is often combined with other illicit substances such as fentanyl. There are no rapid tests for xylazine, although there are specialty tests that can be ordered. Xylazine represents a major threat to street drug users and another challenge to emergency healthcare workers, first responders, and others who care for those who have taken this "new" street drug.

CYP2D6 phenotype explains reported yohimbine concentrations in four severe acute intoxications

The indole alkaloid yohimbine is an alpha-2 receptor antagonist used for its sympathomimetic effects. Several cases of yohimbine intoxication have been reported and the most recent one involved four individuals taking a yohimbine-containing drug powder. All individuals developed severe intoxication symptoms and were admitted to the hospital. Even though all individuals were assumed to have taken the same dose of the drug powder, toxicology analyses revealed yohimbine blood concentrations of 249–5631 ng/mL, amounting to a 22-fold difference. The reason for this high variability remained to be elucidated. We used recently reported knowledge on the metabolism of yohimbine together with state-of-the art nonlinear mixed-effects modelling and simulation and show that a patient’s cytochrome P450 2D6 (CYP2D6) phenotype can explain the large differences observed in the measured concentration after intake of the same yohimbine dose. Our findings can be used both for the identification of safe doses in therapeutic use of yohimbine and for an explanation of individual cases of overdosing.

Complementary and alternative medicine

Complementary and alternative medicine is used worldwide. The use of plant-based medicines for the prevention or treatment of disease is prevalent but not regulated or studied. Multiple countries are implementing pharmacovigilance systems to monitor the use and safety of dietary supplements. Reporting mechanisms continue to be sporadic and inconsistent, based mainly on consumer or healthcare provider reports outlining individual adverse effects (AEs) from dietary supplements. Supplement product ingredient lists may be inaccurate, claims biased, and Evidence-Based information regarding risks and benefits lacking. Healthcare providers should familiarize themselves with complementary medicine practices, the benefits and associated risks to best care for their patient populations.

A global pandemic marked 2020 with the emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A short review of vitamin and plant-based prevention, treatment, and associated ramifications with use of these products for coronavirus disease 2019 (COVID-19) is provided. Another world-wide dilemma is food security. Nutrieconomics and the socioeconomic ramifications of food are reviewed from a wider timeframe.

Reports and reviews from 2020 describe AEs of complementary and alternative medicine and herbal dietary supplements. These are listed alphabetically by plant or supplement name.