Caffeine occurs naturally in various foods, such as coffee, tea, and cocoa, and it has been used safely as a mild stimulant for a long time. However, excessive caffeine consumption (1~1.5 g/day) can cause caffeine poisoning (caffeinism), which includes symptoms such as anxiety, agitation, insomnia, and gastrointestinal disorders. Recently, there has been increasing interest in the effect of caffeine consumption as a protective factor or risk factor for neurological and psychiatric disorders. Currently, the importance of personalized medicine is being emphasized, and research on sex/gender differences needs to be conducted. Our review focuses on the effect of caffeine consumption on several neurological and psychiatric disorders with respect to sex differences to provide a better understanding of caffeine use as a risk or protective factor for those disorders. The findings may help establish new strategies for developing sex-specific caffeine therapies.

https://www.mdpi.com/2072-6643/12/10/3080/pdf

Effect of Caffeine Consumption on the Risk for Neurological and Psychiatric Disorders: Sex Differences in Human.

Oxidized biochar obtained from pine needles as a novel adsorbent to remove caffeine from aqueous solutions

We compared the bronchodilator effects and pharmacokinetics of orally administered caffeine (10 mg per kilogram of body weight) and theophylline (5 mg per kilogram) in a double-blind, single-dose study in asthmatic patients 8 to 18 years of age. After 48 hours of withdrawal of all methylxanthines, 13 patients received caffeine and 10 received theophylline. Significant improvements in forced vital capacity, forced expiratory volume in one second, and forced expiratory flow rates occurred from one to six hours after administration of either caffeine or theophylline. The bronchodilator effect of caffeine did not differ significantly from that of theophylline and was maximal two hours after ingestion of each drug. Peak serum levels of caffeine (13.5 +/- 2.9 mg per liter) occurred at one hour, and peak levels of theophylline (8.4 +/- 1.7 mg per liter) at 2.2 +/- 0.8 hours. The mean serum half-time for caffeine was 3.9 +/- 1.4 hours and that for theophylline was 5.8 +/- 1.7 hours. All patients receiving caffeine metabolized it to paraxanthine, theobromine, and theophylline. Mild, transient side effects were seen after both caffeine and theophylline. Vital signs did not change significantly after either drug. We conclude that caffeine, a commonly available chemical, is an effective bronchodilator in young patients with asthma.

169 The bronchodilator effects and pharmacokinetics of caffeine in asthma

In Western populations, the caffeine intake of young adults has received significant attention in the research literature; our knowledge in other societies remained limited. The objective of this research is to quantify the amount of ingested caffeine and how this is related to measures of physical and mental health in a Bahraini population. A semi-quantitative food frequency questionnaire was used to estimate caffeine intake from coffee, tea, cocoa, soft drinks, energy drinks, chocolates, and over-the-counter medications. Associations between caffeine intake, demographic variables and 25 symptoms measured using the Hopkins Symptoms Checklist-25 were examined. A convenience sample of university students in Bahrain (n = 727) was surveyed. Caffeine, in any form, was consumed by 98% of students. Mean daily caffeine consumption was 268 mg/day, with males consuming more than females. Coffee was the main source of caffeine intake, followed by black tea and energy drinks. Participants consuming 400 mg/day or more showed a statistically and significantly twice as high risk for five symptoms, these were: headaches, spells of terror or panic, feeling trapped or caught, worrying too much about things, and having feelings of worthlessness. The prevalence of caffeine intake among university students in Bahrain is high. The overall mean intake of caffeine from all sources by university students was within levels considered to be acceptable by many dietary recommendations. High caffeine intake was associated with an anxiogenic effect in the surveyed students.

https://www.mdpi.com/2304-8158/9/4/473/pdf

Intake of Caffeine and Its Association with Physical and Mental Health Status among University Students in Bahrain.

Τhe application of oxidized carbon derived from Luffa cylindrica for caffeine removal. Equilibrium, thermodynamic, kinetic and mechanistic analysis

Caffeine is a widely recognized psychostimulant compound with a long history of consumption by humans. While it has received a significant amount of attention there is still much to be learned with respect to its toxicology in humans, especially in cases of overdose. A review of the history of consumption and the clinical toxicology of caffeine including clinical features, pharmacokinetics, toxicokinetics, a thorough examination of mechanism of action and management/treatment strategies are undertaken. While higher (i.e., several grams) quantities of caffeine are known to cause toxicity and potentially lethality, cases of mainly younger individuals who have experienced severe side effects and death despite consuming doses not otherwise known to cause such harm is troubling and deserves further study. An attempted case reconstruction is performed in an effort to shed light on this issue with a focus on the pharmacokinetics and pharmacodynamics of caffeine.

The clinical toxicology of caffeine: A review and case study.

Sympathomimetic amine compounds are often pooled together and incorrectly assumed to be interchangeable with respect to potential adverse effects. A brief and specific review of sympathomimetic compounds and one instance (i.e., hepatotoxicity) where these compounds have been improperly grouped together is covered. A review of the proposed mechanisms through which known hepatotoxic sympathomimetic agents (e.g., 3,4-methylenedioxymethamphetamine or MDMA, methamphetamine and amphetamine) cause liver injury, along with a corresponding review of in vitro data, interventional data, animal model studies and observational data allow for a comparison/contrast of different agents and reveals a lack of potential toxicity for some agents (e.g., pseudoephedrine, phenylephrine, ephedrine, 1,3-dimethylamylamine, phentermine) in this broad category. Data show that compounds within the broad group of sympathomimetics display divergent pharmacological and toxicological profiles and can be clearly distinguished with respect to liver injury. These data serve as a reminder to clinicians and others, that even small structural differences between molecules can lead to drastically different pharmacological/toxicological profiles and that one should not assume that all sympathomimetic agents are hepatotoxic. Such assumptions could lead to diagnostic errors and incorrect or insufficient treatment.

Sympathomimetic amine compounds and hepatotoxicity: Not all are alike-Key distinctions noted in a short review.

Testosterone is the predominant androgen in men and has important physiological functions. Due to declining testosterone levels from a variety of causes, testosterone replacement therapy (TRT) is increasingly utilized, while testosterone is also abused for aesthetic and performance-enhancing purposes. It has been increasingly speculated that aside from more well-established side effects, testosterone may cause neurological damage. However, the in vitro data utilized to support such claims is limited due to the high concentrations used, lack of consideration of tissue distribution, and species differences in sensitivity to testosterone. In most cases, the concentrations studied in vitro are unlikely to be reached in the human brain. Observational data in humans concerning the potential for deleterious changes in brain structure and function are limited by their inherent design as well as significant potential confounders. More research is needed as the currently available data are limited; however, what is available provides rather weak evidence to suggest that testosterone use or abuse has neurotoxic potential in humans.

/pdf/misadventures-in-toxicology-concentration-matters-for-3mhnwnnr.pdf

Cyril Willson

Papers

The clinical toxicology of caffeine: A review and case study.

Sympathomimetic amine compounds and hepatotoxicity: Not all are alike-Key distinctions noted in a short review.

Misadventures in Toxicology: Concentration Matters for Testosterone-Induced Neurotoxicity