Cardiovascular and temperature adverse actions of stimulants

The stimulant cathine from Khat causes tachycardia indirectly in the rat

Leaves of the Khat plant are widely consumed in the Horn of Africa, Yemen and the Jazan region of Saudi Arabia. I have investigated the mode of cardiovascular and autonomic actions of the stimulant cathine from Khat in terms of direct or indirect adrenergic actions in anaesthetised male and female rats, and in isolated tissues. Male and female rats were anaesthetised with pentobarbitone and changes in diastolic blood pressure and cardioaccelerator responses were examined in vehicle-treated or chemically sympathectomised rats. Cathine produced marked tachycardia and smaller blood pressure responses in vehicle-treated animals, with significant rises in heart rate occurring at cathine (0.1 mg/kg). In sympathectomised rats, cardiac actions were greatly attenuated in both male and female animals, with no differences between male and female rats. Although pressor responses to cathine were relatively small, sympathectomy significantly reduced these responses in female, but not male, rats. In rat aorta and spleen, cathine produced almost no direct contractions. It is concluded that cathine acts predominantly indirectly, presumably by the release of noradrenaline, in both male and female rats to produce cardiovascular actions. This may have implications for adverse cardiovascular actions of consumption of the plant Khat, particularly with dried Khat, in which actions of cathine may predominate over those of cathinone.

Associations between short-term ambient temperature exposure and emergency department visits for amphetamine, cocaine, and opioid use in California from 2005 to 2019

Substance use disorder is a growing public health challenge in the United States. People who use drugs may be more vulnerable to ambient heat due to the effects of drugs on thermoregulation and their risk environment. There have been limited population-based studies of ambient temperature and drug-related morbidity. We examined short-term associations between daily ambient temperature and emergency department (ED) visits for use or overdose of amphetamine, cocaine and opioids in California during the period 2005 to 2019. Daily ZIP code-level maximum, mean, and minimum temperature exposures were derived from 1-km data Daymet products. A time-stratified case-crossover design was used to estimate cumulative non-linear associations of daily temperature for lag days 0 to 3. Stratified analyses by patient sex, race, and ethnicity were also conducted. The study included over 3.4 million drug-related ED visits. We found positive associations between daily temperature and ED visits for all outcomes examined. An increase in daily mean temperature from the 50th to the 95th percentile was associated with ED visits for amphetamine use (OR = 1.072, 95% CI: 1.058, 1.086), cocaine use (OR = 1.044, 95% CI: 1.021, 1.068 and opioid use (OR = 1.041, 95% CI: 1.025, 1.057). Stronger positive associations were also observed for overdose: amphetamine overdose (OR = 1.150, 95% CI: 1.085, 1.218), cocaine overdose (OR = 1.159, 95% CI: 1.053, 1.276), and opioid overdose (OR = 1.079, 95% CI: 1.054, 1.106). In summary, people who use stimulants and opioids may be a subpopulation sensitive to short-term higher ambient temperature. Mitigating heat exposure can be considered in harm reduction strategies in response to the substance use epidemic and global climate change.

Stimulant and hallucinogenic novel psychoactive substances; an update

INTRODUCTION

The renewed interest in considering a range of stimulants, psychedelics and dissociatives as therapeutics emphasizes the need to draft an updated overview of these drugs' clinical and pharmacological issues.

AREAS COVERED

The focus here was on: stimulants (e.g. amphetamines, methamphetamine, and pseudoephedrine; phenethylamines; synthetic cathinones; benzofurans; piperazines; aminoindanes; aminorex derivatives; phenmetrazine derivatives; phenidates); classical (e.g. ergolines; tryptamines; psychedelic phenethylamines), and atypical (e.g. PCP/ketamine-like dissociatives) psychedelics.Stimulant and psychedelics are associated with: a) increased central DA levels (psychedelic phenethylamines, synthetic cathinones and stimulants); b) 5-HT receptor subtypes' activation (psychedelic phenethylamines; recent tryptamine and lysergamide derivatives); and c) antagonist activity at NMDA receptors, (phencyclidine-like dissociatives).

EXPERT OPINION

Clinicians should be regularly informed about the range of NPS and their medical, psychobiological and psychopathological risks both in the acute and long term. Future research should focus on an integrative model in which pro-drug websites' analyses are combined with advanced research approaches, including computational chemistry studies so that in vitro and in vivo preclinical studies of index novel psychoactives can be organized. The future of psychedelic research should focus on identifying robust study designs to convincingly assess the potential therapeutic benefits of psychedelics, molecules likely to present with limited dependence liability levels.

Athletes With Attention-Deficit/Hyperactivity Disorder: Position Statement of the American Medical Society for Sports Medicine

ABSTRACT

Athletes of all ages may be affected by medical and mental health issues. Sports medicine physicians should be familiar with common conditions that may affect the well-being of athletes, such as attention-deficit/hyperactivity disorder (ADHD). ADHD behaviors have the potential to affect a person's ability to concentrate. It is likely that social and cognitive therapies combined with pharmacotherapy will be the most effective way to treat ADHD in athletes. Medications used for ADHD, especially stimulant types, are known to improve alertness, reaction time, anaerobic performance, and endurance, which would potentially improve athletic performance. Furthermore, stimulant medications may enable student athletes with ADHD to focus on academic studies for longer periods of time, beyond usual levels of fatigue, important for those who may be exhausted after practices and games. The purported performance enhancement effects and potential adverse effects of stimulant medications have prompted many sports governing bodies to ban prescription stimulants or establish strict rules for their use. Athletes taking physician-prescribed stimulants to treat ADHD need to provide the appropriate documentation for approval before competition or risk punitive measures. Physicians should strive to provide a high quality of care to athletes with ADHD through early diagnosis, appropriate and careful multidisciplinary treatment, and complete and timely documentation to facilitate continued sports participation.

Pharmacology of Drugs Used as Stimulants

Psychostimulant, cardiovascular, and temperature actions of stimulants involve adrenergic (norepinephrine), dopaminergic (dopamine), and serotonergic (serotonin) pathways. Stimulants such as amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), or mephedrone can act on the neuronal membrane monoamine transporters NET, DAT, and SERT and/or the vesicular monoamine transporter 2 to inhibit reuptake of neurotransmitter or cause release by reverse transport. Stimulants may have additional effects involving pre- and postsynaptic/junctional receptors for norepinephrine, dopamine, and serotonin and other receptors. As a result, stimulants may have a wide range of possible actions. Agents with cocaine or MDMA-like actions can induce serious and potentially fatal adverse events via thermodysregulatory, cardiovascular, or other mechanisms. MDMA-like stimulants may cause hyperthermia that can be life threathening. Recreational users of stimulants should be aware of the dangers of hyperthermia in a rave/club environment.