Toxic Chemicals Everyone Regularly Consumes

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Published: Friday, 03 March 2023 08:45

Environmental toxins that find their way into our air, food, and water over the past few decades have dramatically increased.  Many of these substances have adverse health effects in both humans and animals that may account for the increase of cancer, including an increase in colon cancer in younger age groups.  The following article that appeared in a recent issue of Medscape for Physicians summarizes the toxicology and dangers of several of the more common environmental adulterants.

If the pandemic served as a window into our health, what it revealed was a US population that is not only sick but also seemingly only getting sicker. Life expectancy is falling precipitously. Three fourths of Americans are overweight or obese, half have diabetes or prediabetes, and a majority are metabolically unhealthy. Furthermore, the rates of allergic, inflammatory, and autoimmune diseases are rising at rates of 3%-9% per year in the West, far faster than the speed of genetic change in this population.

Of course, diet and lifestyle are major factors behind such trends, but a grossly underappreciated driver in what ails us is the role of environmental toxins and endocrine-disrupting chemicals. In years past, these factors have largely evaded the traditional Western medical establishment; however, mounting evidence now supports their significance in fertility, metabolic health, and cancer.

Although several industrial chemicals and toxins have been identified as carcinogens and have subsequently been regulated, many more remain persistent in the environment and continue to be freely used. It is therefore incumbent upon both the general public and clinicians to be knowledgeable about these exposures. Here, we review some of the most common exposures and the substantial health risks associated with them, along with some general guidance around best practices for how to minimize exposure.

Microplastics 

"Microplastics" is a term used to describe small fragments or particles of plastic breakdown or microbeads from household or personal care products, measuring less than 5 mm in length.

Plastic waste is accumulating at alarming and devastating proportions — by 2050, it is estimated that by weight, there will be more plastic than fish in the oceans. That translates into hundreds of thousands of tons of microplastics and trillions of these particles in the seas. A recent study demonstrated that microplastics were present in the bloodstream in the majority of 22 otherwise healthy participants.

Since the 1950s, plastic exposure has been shown to promote tumorigenesis in animal studies, and in vitro studies have demonstrated the toxicity of microplastics at the cellular level. However, it is not well known whether the plastic itself is toxic or if it simply serves as a carrier for other environmental toxins to bioaccumulate.

According to Tasha Stoiber, a senior scientist at the Environmental Working Group (EWG), "Microplastics have been widely detected in fish and seafood, as well as other products like bottled water, beer, honey, and tap water." EWG states there are no formal advisories on fish consumption to avoid exposure to microplastics at the moment.

Pressure also is mounting for a ban on microbeads in personal care products.

Until such bans are put in place, it is advised to avoid single-use plastics, favor reusable tote bags for grocery shopping rather than plastic bags, and opt for loose leaf tea or paper tea bags rather than mesh-based alternatives.

Phthalates 

Phthalates are chemicals used to make plastics soft and durable, as well as to bind fragrances. They are commonly found in household items such as vinyl (eg, flooring, shower curtains) and fragrances, air fresheners, and perfumes.

Phthalates are known hormone-disrupting chemicals, exposure to which has been associated with abnormal sexual and brain development in children, as well as lower levels of testosterone in men. Exposures are thought to occur via inhalation, ingestion, and skin contact; however, fasting studies demonstrate that a majority of exposure is probably food related.

To avoid phthalate exposures, recommendations include avoiding polyvinyl chloride plastics (particularly food containers, plastic wrap, and children's toys), which is identifiable by the recycle code number 3, as well as air fresheners and fragranced products.

The EWG's Skin Deep database provides an important resource on phthalate-free personal care products.

Despite pressure from consumer advocacy groups, the US Food and Drug Administration has not yet banned phthalates in food packaging.

Bisphenol A (BPA) 

BPA is a chemical additive used to make clear and hard polycarbonate plastics, as well as epoxy and thermal papers. BPA is one of the highest-volume chemicals, with roughly 6 billion pounds produced each year. BPA is traditionally found in many clear plastic bottles and sippy cups, as well as in the lining of canned foods.

Structurally, BPA acts as an estrogen mimetic and has been associated with cardiovascular disease, obesity, and male sexual dysfunction. Since 2012, BPA has been banned in sippy cups and baby bottles, but there is some debate as to whether its replacements (bisphenol S and bisphenol F) are any safer; they appear to have similar hormonal effects as BPA.

As with phthalates, the majority of ingestion is thought to be food related. BPA has been found in more than 90% of a representative study population in the United States.

Guidance advises avoiding polycarbonate plastics (identifiable with the recycling code number 7), as well as avoiding handling thermal papers such as tickets and receipts, if possible. Food and beverages should be stored in glass or stainless steel. If plastic must be used, opt for polycarbonate- and polyvinyl chloride–free plastics, and food and beverage should never be reheated in plastic containers or wrapping. Canned foods should ideally be avoided, particularly canned tunas and condensed soups. If canned products are bought, they should ideally be BPA free.

Dioxins and Polychlorinated Biphenyls (PCBs) 

Dioxins are mainly the byproducts of industrial practices; they are released after incineration, trash burning, and fires. PCBs, which are somewhat structurally related to dioxins, were previously found in products such as flame retardants and coolants. Dioxins and PCBs are often grouped in the same category under the umbrella term "persistent organic pollutants" because they break down slowly and remain in the environment even after emissions have been curbed.

Tetrachlorodibenzodioxin, perhaps the best-known dioxin, is a known carcinogen. Dioxins also have been associated with a host of health implications in development, immunity, and reproductive and endocrine systems. Higher levels of PCB exposure have also been associated with an increased risk for mortality from cardiovascular disease.

Notably, dioxin emissions have been reduced by 90% since the 1980s, and the US Environmental Protection Agency (EPA) has banned the use of PCBs in industrial manufacturing since 1979. However, environmental dioxins and PCBs still enter the food chain and accumulate in fat.

The best ways to avoid exposures are through limiting meat, fish, and dairy consumption and trimming the skin and fat from meats. The level of dioxins and PCBs found in meat, eggs, fish, and dairy are approximately 5-10 times higher than they are in plant-based foods. Research has shown that farmed salmon is likely to be the most PCB-contaminated protein source in the US diet; however, newer forms of land-based and sustainable aquaculture probably avoid this exposure.

Pesticides 

The growth of modern monoculture agriculture in the United States over the past century has coincided with a dramatic surge in the use of industrial pesticides. In fact, over 90% of the US population have pesticides in their urine and blood, regardless of where they live. Exposures are thought to be food related.

Approximately 1 billion pounds of pesticides are used annually in the United States, including nearly 300 million pounds of glyphosate, which has been identified as a probable carcinogen by European agencies. The EPA has not yet reached this conclusion, although the matter is currently being litigated.

A large European prospective cohort trial demonstrated a lower risk for cancer in those with a greater frequency of self-reported organic food consumption. In addition to cancer risk, relatively elevated blood levels of a pesticide known as beta-hexachlorocyclohexane (B-HCH) are associated with higher all-cause mortality. Also, exposure to DDE — a metabolite of DDT, a chlorinated pesticide heavily used in the 1940s-1960s that still persists in the environment today — has been shown to increase the risk for Alzheimer's-type dementia as well as overall cognitive decline.

Because these chlorinated pesticides are often fat soluble, they seem to accumulate in animal products. Therefore, people consuming a vegetarian diet have been found to have lower levels of B-HCH. This has led to the recommendation that consumers of produce should favor organic over conventional, if possible. Here too, the EWG provides an important resource to consumers in the form of shopper guides regarding pesticides in produce.

Per- and Polyfluoroalkyl Substances (PFAS) 

PFAS are a group of fluorinated compounds discovered in the 1930s. Their chemical composition includes a durable carbon-fluoride bond, giving them a persistence within the environment that has led to their being referred to as "forever chemicals."

PFAS have been detected in the blood of 98% of Americans, and in the rainwater of locations as far afield as Tibet and Antarctica. Even low levels of exposure have been associated with an increased risk for cancer, liver disease, low birthweight, and hormonal disruption.

The properties of PFAS also make them both durable at very high heat and water repellent. Notoriously, the chemical was used by 3M to make Scotchgard for carpets and fabrics and by Dupont to make Teflon for nonstick coating of pots and pans. Although perfluorooctanoic acid (PFOA) was removed from nonstick cookware in 2013, PFAS — a family of thousands of synthetic compounds — remain common in fast-food packaging, water- and stain-repellent clothing, firefighting foam, and personal care products. PFAS are released into the environment during the breakdown of these consumer and industrial products, as well as from dumping from waste facilities.

Alarmingly, the EWG notes that up to 200 million Americans may be exposed to PFAS in their drinking water. In March 2021, the EPA announced that they will be regulating PFAS in drinking water; however, the regulations have not been finalized. Currently, it is up to individual states to test for its presence in the water. The EWG has compiled a map of all known PFAS contamination sites.

To avoid or prevent exposures from PFAS, recommendations include filtering tap water with either reverse osmosis or activated carbon filters, as well as avoiding fast food and carry-out food, if possible, and consumer products labeled as "water resistant," "stain-resistant," and "nonstick."

In a testament to how harmful these chemicals are, the EPA recently revised their lifetime health advisories for PFAS, such as PFOA, to 0.004 parts per trillion, which is more than 10,000 times smaller than the previous limit of 70 parts per trillion. The EPA also has proposed formally designating certain PFAS chemicals as "hazardous substances."

Inflation Reduction Act Destroys Drug Development

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Published: Friday, 04 November 2022 12:59

Recently an article appeared in the Wall Street Journal regarding the Inflation Reduction Act and the effects it will have on the development of new medical and surgical treatments.  Those effects are numerous and profound, and also come with a health and safety impact.  Thus, toxicologists and other medical safety experts have been paying close attention to developments.  I include the WSJ article below for your information.

It may take years before we can fully appreciate the impact of the Inflation Reduction Act on the pharmaceutical industry, but we’re already getting signs of the damage. While Democrats boast that they’ve given Medicare the power to “negotiate” drug prices, the effect has been to saddle manufacturers with a complex and ill-conceived price-setting scheme. In response, many have canceled drug-development programs, resulting in an unfortunate but predictable loss for patients nationwide.

One poorly crafted provision is driving companies away from research into treating rare diseases. In its Oct. 27 earnings statement, Alnylam announced it is suspending development of a treatment for Stargardt disease, a rare eye disorder, because of the company’s need “to evaluate impact of the Inflation Reduction Act.” Alnylam’s decision turns on a provision in the Democrats’ bill that exempts from price-setting negotiations drugs that treat only one rare disease. The company’s drug is currently marketed as treating only amyloidosis, and thus is exempt from Medicare’s price setting. If Alnylam proceeded with research into treating Stargardt, it would lose its exemption.

Inflation Reduction Act Destroys Drug Development

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Published: Friday, 04 November 2022 12:59

Recently an article appeared in the Wall Street Journal regarding the Inflation Reduction Act and the effects it will have on the development of new medical and surgical treatments.  Those effects are numerous and profound, and also come with a health and safety impact.  Thus, toxicologists and other medical safety experts have been paying close attention to developments.  I include the WSJ article below for your information.

It may take years before we can fully appreciate the impact of the Inflation Reduction Act on the pharmaceutical industry, but we’re already getting signs of the damage. While Democrats boast that they’ve given Medicare the power to “negotiate” drug prices, the effect has been to saddle manufacturers with a complex and ill-conceived price-setting scheme. In response, many have canceled drug-development programs, resulting in an unfortunate but predictable loss for patients nationwide.

One poorly crafted provision is driving companies away from research into treating rare diseases. In its Oct. 27 earnings statement, Alnylam announced it is suspending development of a treatment for Stargardt disease, a rare eye disorder, because of the company’s need “to evaluate impact of the Inflation Reduction Act.” Alnylam’s decision turns on a provision in the Democrats’ bill that exempts from price-setting negotiations drugs that treat only one rare disease. The company’s drug is currently marketed as treating only amyloidosis, and thus is exempt from Medicare’s price setting. If Alnylam proceeded with research into treating Stargardt, it would lose its exemption.

MDMA Microdosing for Depression and Anxiety

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Published: Tuesday, 26 May 2020 21:18

Usually when we think of MDMA, Molly's, Ecstasy, or Methamphetamine in the context of toxicology, we think of poisoning and overdose.  This blog is about the opposite, the treatment of depression and anxiety with very low doses of these methamphetamine-derived substances.  And the results have been surprising good.

Brain Damage From Alcohol Continues After Abstinence

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Published: Tuesday, 28 January 2020 21:06

Some recent research has elegantly established that when an alcoholic stops drinking brain damage persists and actually progresses.  

Damage to the brain caused by alcohol continues during the first few weeks of abstinence, a finding that refutes the notion that the brain begins to normalize immediately after individuals stop drinking.

"Until now, nobody could believe that in the absence of alcohol the damage in the brain would progress," study investigator Santiago Canals, PhD, of the Institute of Neuroscience of Alicante, Consejo Superior de Investigaciones Científicas–Universidad Miguel Hernández, Spain, said in a news release.

The study was published online April 3 in JAMA Psychiatry.

The researchers assessed microstructural alterations in white matter after long-term alcohol exposure and during early abstinence in 91 men (mean age, 46) who had alcohol use disorder (AUD).

The men were hospitalized and were undergoing detoxification treatment, which guaranteed that they did not drink alcohol. Thirty-six healthy men of similar age who did not have AUD served as control persons.

The researchers found diffuse microstructural changes in white matter in the men with AUD compared with the control persons. These changes primarily affected the right hemisphere and the frontal region of the brain. These changes progressed during 2 to 6 weeks of abstinence.

"The study was not designed to look further in time, also due to the fact that our results were unexpected," study coinvestigator Wolfgang Sommer, MD, PhD, of the University of Heidelberg, Germany, told Medscape Medical News.

"Other studies looked at a longer time horizon and typically found signs of recovery, both of the brain structure and its function. Nevertheless, we need more research to understand what is going on here and what are the temporal aspects of the underlying phenomena," said Sommer.

The researchers replicated their observations in an established rat model of excessive alcohol consumption.

"The fact that the findings in humans mirror those in rats may establish a relationship between the observed changes and alcohol consumption, which is difficult to verify based on human results only, given the large heterogeneity of the abuse patterns, medication for relief of withdrawal symptoms, and comorbidities among patients with AUD," the researchers write.

"This result establishes the utility of diffusion imaging for monitoring the brain status as a possible noninvasive biomarker of AUD progression and, potentially, of treatment response," they add.

"These types of translational studies are crucial to help fill in gaps in addiction research," Marisa Silveri, PhD, director of the Neurodevelopmental Laboratory on Addictions and Mental Health, McLean Hospital, Belmont, Massachusetts, and associate professor of psychiatry at Harvard Medical School, Boston, told Medscape Medical News.

"The findings do fly a little in the face of what we know, because when people become abstinent, it usually doesn't take them long for things like brain chemistry and cognition to improve, somewhat after abstinence. But it's studies like these that uncover some more micro level cellular indicators that tell us that just because you can recover some function, it doesn't necessarily mean the brain is returned to a healthy state," said Silveri.

"That's an important message because people often think that when they no longer feel the acute intoxicating effects of alcohol, that it's not still having an effect, and we do know from many studies that there are residual effects of alcohol intoxication on neurobiology.

"The brain is a fantastic orchestra of networks, and understanding some of the subtler changes and what they mean is work that is most needed," she added.

The study appeared in the following journal: 

JAMA Psychiatry. Published online April 3, 2019. Abstract

Kraton Products Cause Illness-Heavy Metal Poisoning

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Published: Monday, 25 November 2019 12:49

Final results of tests performed by the US Food and Drug Administration (FDA) on 30 kratom products confirm the presence of heavy metals, including lead and nickel, at concentrations not considered safe for human consumption, the FDA said Wednesday. 

The FDA first warned of "disturbingly" high levels of heavy metals, including lead and nickel, last November, as reported by Medscape Medical News.  The FDA has posted a list of the kratom products and concentrations of heavy metals found in them on its website. Based on reported patterns of kratom use, heavy kratom users may be exposed to levels of lead and nickel many times greater than the safe daily exposure, the FDA warns in a statement. 

Based on these test results, the typical long-term kratom user could potentially develop heavy metal poisoning, which could include nervous system or kidney damage, anemia, high blood pressure, and increased risk of certain cancers, the agency adds.

"Over the last year, the FDA has issued numerous warnings about the serious risks associated with the use of kratom, including novel risks due to the variability in how kratom products are formulated, sold and used both recreationally and by those who are seeking to self-medicate for pain or to treat opioid withdrawal symptoms," FDA Commissioner Scott Gottlieb, MD, said in the statement. 

Gottlieb said the FDA has been "attempting to work" with the companies whose kratom products contain high levels of heavy metals.  The agency has released the final laboratory results to the public to "help make sure consumers are fully informed of these risks." "The data from these results support our public warning about the risk of heavy metals in kratom products. The findings of identifying heavy metals in kratom only strengthen our public health warnings around this substance and concern for the health and safety of Americans using it," he added. 

No Approved Use Kratom is derived from the leaves of the kratom tree (Mitragyna speciosa), which is native to Thailand, Indonesia, and Papua New Guinea. The botanical's popularity has been increasing in the United States, with manufacturers — and those who take it — claiming it can help treat pain, anxiety, depression, and more recently, opioid withdrawal. Last year, an analysis of kratom by FDA scientists found that its compounds act like prescription-strength opioids. In addition to heavy metal contamination, kratom products have also been found to be contaminated with Salmonella, resulting in numerous illnesses and product recalls. Kratom has been linked to numerous deaths in the United States. There are currently no FDA-approved uses for kratom, and the agency has advised against using kratom or its psychoactive compounds mitragynine and 7-hydroxymitragynine in any form and from any manufacturer. 

Health providers are encouraged to report any adverse reactions related to kratom products to MedWatch, the FDA's safety information and adverse event reporting program.

Updates on Illicit Drug Overdose

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Published: Sunday, 10 November 2019 18:19

Drug overdose remains a significant concern worldwide, with nearly half a million deaths annually. In the United States, drug overdoses are the leading cause of death for adults younger than 55 years. Drug-related deaths now outnumber those attributed to motor vehicle accidents and homicides. According to information from the Centers for Disease Control and Prevention (CDC), the drugs most commonly involved in overdose deaths include opioids (eg, fentanyl, heroin, oxycodone), cocaine, methamphetamines, and benzodiazepines.

Naloxone has been lifesaving in many scenarios, so the CDC recently issued recommendations regarding its use in patients taking opioids. The CDC recommends that clinicians strongly consider prescribing or coprescribing naloxone and providing education about its use in these types of patients taking opioids:

• Those who are receiving opioids at a dosage of 50 morphine milligram equivalents per day or greater
• Those who have respiratory conditions such as chronic obstructive pulmonary disease or obstructive sleep apnea (regardless of opioid dose)
• Those who have been prescribed benzodiazepines (regardless of opioid dose)
• Those who have a nonopioid substance use disorder, report excessive alcohol use, or have a mental health disorder (regardless of opioid dose)

The CDC also recommends naloxone in patients who are at high risk for experiencing or responding to an opioid overdose, including the following:

• Those known to use heroin or illicit synthetic opioids or misuse prescription opioids
• Those using other illicit drugs such as stimulants, including methamphetamine and cocaine
• Those receiving treatment for opioid use disorder, including medication-assisted treatment with methadone, buprenorphine, or naltrexone
• Those with a history of opioid misuse who were recently released from incarceration or other controlled settings where tolerance to opioids has been lost

Most of the deaths from synthetic opioids are from fentanyl. Most of the increases in fentanyl deaths in recent years do not involve prescription fentanyl but are related to illicitly made fentanyl mixed with or sold as heroin—with or without the users' knowledge—and increasingly sold as counterfeit pills.

In the event of an overdose, pertinent history may be obtained from bystanders, family, friends, or emergency medical services (EMS) providers. Pill bottles, drug paraphernalia, or eyewitness accounts may assist in the diagnosis of opioid toxicity. Occasionally, a trial of naloxone administered by an EMS provider is helpful to establish the diagnosis in the prehospital setting.

Patients with opioid toxicity characteristically have a depressed level of consciousness. Opioid toxicity should be suspected when the clinical triad of central nervous system (CNS) depression, respiratory depression, and pupillary miosis are present. Clinicians must be aware that opioid exposure does not always result in miosis (pupillary constriction), and that respiratory depression is the most specific sign. Drowsiness, conjunctival injection, and euphoria are frequently seen.

Drug screens are widely available but rarely alter clinical management in patients with uncomplicated overdoses. Drug screens are most sensitive when performed on urine. Positive results are observed up to 36-48 hours postexposure, but wide variations are possible depending on test sensitivity, dose, route of opioid administration, and the patient's metabolism. In patients with moderate to severe toxicity, performing these baseline studies is appropriate:

• Complete blood cell (CBC) count
• Comprehensive metabolic panel
• Creatine kinase (CK) level
• Arterial blood gas (ABG) determinations

According to American Heart Association guidelines, clear evidence suggests that cocaine can precipitate acute coronary syndrome, and that trying agents that show efficacy in the management of acute coronary syndrome may be reasonable in patients with severe cardiovascular toxicity. Agents that may be used as needed to control hypertension, tachycardia, and agitation include:

• Alpha-blockers (eg, phentolamine)
• Benzodiazepines (eg, lorazepam, diazepam)
• Calcium channel blockers (verapamil)
• Morphine
• Sublingual nitroglycerin

The American Heart Association does not recommend any one of these agents over another in the treatment of cardiovascular toxicity due to cocaine; however, benzodiazepines are often used as first-line treatment.

Cardiopulmonary complaints are the most common presenting manifestations of cocaine abuse and include chest pain (frequently observed in long-term use or overdose), MI, arrhythmia, and cardiomyopathy. In individuals with cocaine-associated MI, median times to the onset of chest pain vary with the route or form of cocaine use: 30 minutes for intravenous use, 90 minutes for crack, and 135 minutes for intranasal use.

Temperature dysregulation is also a problem with cocaine intoxication. Hyperthermia is a marker for severe toxicity, and it is associated with numerous complications, including renal failure, disseminated intravascular coagulation, acidosis, hepatic injury, and rhabdomyolysis. Dopamine plays a role in the regulation of core body temperature, so increased dopaminergic neurotransmission may contribute to psychostimulant-induced hyperthermia in cocaine users, including those with excited delirium.

No laboratory studies are indicated if the patient has a clear history of cocaine use and mild symptoms.

If a history of cocaine use is absent or if the patient has moderate to severe toxicity, appropriate laboratory tests may include:

• CBC count
• Electrolytes, blood urea nitrogen, creatinine, and glucose levels (basic metabolic panel)
• Glucose level
• Pregnancy test
• Calcium level
• ABG analysis
• CK level
• Troponin level (cocaine use does not affect the specificity of troponin assays)
• Urinalysis
• Toxicology screens

Acute and long-term methamphetamine use may lead to abnormal findings on examination of the following organ systems:

• Cardiovascular
• CNS
• Gastrointestinal
• Renal
• Skin
• Dental

There are specific cardiovascular findings associated with acute and long-term methamphetamine use:

• Tachycardia and hypertension is frequently observed
• Atrial and ventricular arrhythmias may occur
• Chest pain from cardiac ischemia and infarction following methamphetamine use has been reported, and patients are at risk because of accelerated atherosclerosis from chronic use; acute aortic dissection or aneurysm has been associated with methamphetamine abuse
• Hypotension may be observed with methamphetamine overdose with profound depletion of catecholamines
• Acute and chronic cardiomyopathy results directly from methamphetamine cardiac toxicity and indirectly from chronic hypertension and ischemia; intravenous use may result in endocarditis; patients may have dyspnea, edema, and other signs of acute congestive heart failure exacerbation

The euphoric effects produced by methamphetamine, cocaine, and various designer amphetamines are similar and may be difficult to clinically differentiate. A distinguishing clinical feature is the longer pharmacokinetic and pharmacodynamic half-life of methamphetamine, which may be as much as 10 times longer than that of cocaine.

Methamphetamine can cause significant CNS and psychiatric activation, so patients who present to emergency departments for acute intoxication often require physical restraint and pharmacologic intervention. Hyperactive or agitated patients can be treated with droperidol or haloperidol, which are butyrophenones that antagonize CNS dopamine receptors and mitigate the excess dopamine produced from methamphetamine toxicity. These medications should be administered intravenously, with doses adjusted based on the symptoms. Droperidol has been subject to a black box warning by the US Food and Drug Administration based on concerns of QT prolongation and the potential for torsades de pointes. As a result, some institutions restrict its use. However, it is important to note that the black box warning specifies dementia-related psychosis and is not supported by the literature for doses below 2.5 mg.

If sedation fails to reduce blood pressure, antihypertensive agents such as beta-blockers and vasodilators are effective in reversing methamphetamine-induced hypertension and tachycardia. With regard to choice of beta-blockers, labetalol is preferred because of its combined anti–alpha-adrenergic and anti–beta-adrenergic effects. Labetalol has been shown to safely lower mean arterial pressure in patients with positive cocaine test results. Carvedilol, like labetalol, is a nonselective beta-blocker with alpha-blocking activity and may also be effective for this indication. Esmolol is advantageous because of its short half-life but must be administered via intravenous drip. Metoprolol has excellent CNS penetration characteristics and may also ameliorate agitation.

Oral benzodiazepine overdoses, without co-ingestion of another drug, rarely result in significant morbidity (eg, aspiration pneumonia, rhabdomyolysis) or mortality; however, in mixed-drug overdoses, they can potentiate the effect of alcohol or other sedative-hypnotic agents. Overdose of ultrashort-acting benzodiazepines (eg, triazolam) is also more likely to result in apnea and death than overdose with longer-acting benzodiazepines. Of the individual benzodiazepines, alprazolam is relatively more toxic than others in overdose.

Immunoassay screening techniques are most commonly performed when benzodiazepine overdose is suspected. These tests typically detect benzodiazepines that are metabolized to desmethyldiazepam or oxazepam; thus, a negative screening result does not rule out the presence of a benzodiazepine.

As with any overdose, the first step is an assessment of the patient's airway, breathing, and circulation, and any issues should be addressed rapidly. In any patient with an altered mental status, blood glucose level should be checked immediately. The cornerstone of treatment in benzodiazepine overdoses is good supportive care and monitoring. Single-dose activated charcoal is not routinely recommended because the risks far outweigh the benefit. Altered mental status greatly increases the risk of aspiration following an oral activated charcoal dose.

Flumazenil is a competitive benzodiazepine receptor antagonist and the only available specific antidote for benzodiazepines. Its use in acute benzodiazepine overdose is controversial, however, and its risks usually outweigh any benefit. In long-term benzodiazepine users, flumazenil may precipitate withdrawal and seizures; in patients taking benzodiazepines for a medical condition, flumenazil may result in exacerbation of the condition. Flumazenil should not be used in patients with long-term benzodiazepine use or in any patient at an increased risk of having a seizure, including those with a seizure history, head injury, co-ingestion of a benzodiazepine and tricyclic antidepressant or other proconvulsant, or even a possible ingestion of a proconvulsant.

In general, when it is the sole agent used, the clinical presentation of heroin poisoning and its diagnosis hold little challenge for experienced healthcare practitioners. The diagnosis of heroin poisoning should be suspected in all comatose patients, especially in the presence of respiratory depression and miosis.

Respiratory depression, due to heroin's effect on the brain's respiratory centers, is a hallmark sign of overdose. However, the presence of tachypnea should prompt the search for complications of heroin use, such as pneumonia, acute lung injury, and pneumothorax, or an alternative diagnosis, such as shock, acidosis, or CNS injury. Tachypnea may also be seen in overdoses of pentazocine or meperidine.

Symptoms generally develop within 10 minutes of intravenous heroin injection. Patients who survive heroin poisoning commonly admit to using more than their usual dose, using heroin again after a prolonged period of abstinence, or using a more concentrated street sample. Coma, respiratory depression, and miosis are the hallmarks of opioid overdose.

Mild hypotension and mild bradycardia are commonly observed with heroin use. These are attributable to peripheral vasodilation, reduced peripheral resistance and histamine release, and inhibition of baroreceptor reflexes. In the setting of heroin overdose, hypotension remains mild. The presence of severe hypotension should prompt a search for other causes of hypotension, such as hemorrhage, hypovolemia, sepsis, pulmonary emboli, and other causes of shock.

Gastric lavage in the setting of oral heroin overdose is generally not recommended because it has no documented value. Furthermore, gastric lavage is contraindicated in "body packers" and "body stuffers," who have ingested packages of drugs, because the procedure may rupture a package. Activated charcoal is becoming increasingly controversial because of the risk of aspiration and charcoal pneumonitis. It may be indicated for orally ingested narcotics with large enterohepatic circulation (eg, propoxyphene, diphenoxylate) but is of no value in pure heroin overdose.

Psychelic Drugs Used to Treat Depression and Anxiety-Toxicology

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Published: Thursday, 16 May 2019 18:11

A very interesting study has recently been done on the effects of a psychedelic substance in a small mitigated-psychedelic dose in the treatment of resistant depression and anxiety. The following is a synopsis of the key points from a recent Medscape article.  The relevance of this study to toxicology is that psychelics can have severe side-effects, some even long-lasting or permanent, even in customary doses, as noted below. Practitioners who treat their patients with these substances should be aware of the medicolegal liability and health risks.

Read more: Psychelic Drugs Used to Treat Depression and Anxiety-Toxicology

Fluorquinolones can kill

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Published: Wednesday, 01 May 2019 13:22

New warning from the FDA-- a warning about Aortic Aneurysm Risk With Fluoroquinolones in patients being treated for common infections

The agency is urging healthcare providers to avoid prescribing the powerful antibiotics to patients with or at risk for an aortic aneurysm, such as those with peripheral atherosclerotic vascular disease, hypertension, certain genetic conditions such as Marfan syndrome and Ehlers-Danlos syndrome, and the elderly. This antibiotic is one of the most commonly prescribed antibiotics for braonchitis, sinusitis, bladder infections, and pneumonia.

"Although the risk of aortic aneurysm or dissection is low, we've observed that patients are twice as likely to experience an aortic aneurysm or dissection when prescribed a fluoroquinolone drug," FDA commissioner Scott Gottlieb, MD, said in the Drug Safety Communication.

"For patients who have an aortic aneurysm or are known to be at risk of an aortic aneurysm, we do not believe the benefits outweigh this risk, and alternative treatment should be considered."

The FDA reviewed adverse event reports and four recently published observational studies showing an increased risk of aortic aneurysm or dissection associated with fluoroquinolone use, which can lead to dangerous bleeding or even death.

The underlying reason for this increased risk cannot be determined, the statement notes. The background risk of aortic aneurysm also can vary depending on the population — from nine events/100,000 people/year in the general population to 300 events/100,000 people/year in the highest-risk individuals.

"For some patients, the benefits of fluoroquinolones may continue to outweigh the risks for treatment of serious bacterial infections, such as pneumonia or intra-abdominal infections, but there are other serious, known risks associated with these strong antibiotics that must be carefully weighed when considering their use," Gottlieb said. 

The FDA has issued several prior safety communications about fluoroquinolone use, including in  July 2018 (significant decreases in blood sugar and certain mental health side effects),  July 2016  (disabling side effects of the tendons, muscles, joints, nerves, and central nervous system),  May 2016 (restrict use for certain uncomplicated infections),  August 2013  (peripheral neuropathy), and  July 2008  (tendinitis and tendon rupture). 

Edible Marijuana is Potentially Dangerous

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Published: Wednesday, 10 April 2019 13:42

The number of cannabis-associated emergency department (ED) visits has risen sharply since marijuana was legalized in Colorado. New data show that although inhalable cannabis use accounts for most of these visits, edible cannabis is tied to a disproportionate number of visits, and patients present with different symptoms.

Although less frequent overall, edible cannabis products lead to more acute psychiatric events and cardiovascular symptoms than inhaled exposure. Researchers at the University of Colorado report their findings in an article published online recently in the Annals of Internal Medicine.

Edible cannabis has been considered to be more toxic than inhalable cannabis, particularly in light of accumulating poison center data on its associated adverse events (AEs) and anecdotal reports from adult users. In addition, the only deaths in Colorado that have been conclusively linked to cannabis use have involved edible products.

Nevertheless, the relative potential harms of inhalable and edible cannabis products have been poorly characterized.

With this in mind, Monte and colleagues conducted a study to compare adult ED visits related to edible and inhalable cannabis use. Using chart review, the researchers tracked 9973 ED visits to the University of Colorado Health emergency department from 2012 through 2016 that included an ICD-9 or -10 code for cannabis use. Of those, they found that 2567 (25.7%) of the visits were related to cannabis, with 238 of these (9.3%) linked to edible products.

The most common causes of cannabis-linked ED visits were gastrointestinal symptoms (30.7%), intoxication (29.7%), and psychiatric symptoms (24.7%).

Visits as a result of inhalable cannabis were more likely than those because of edibles to involve gastrointestinal symptoms, the most common of which was cannabinoid hyperemesis syndrome (18% vs 8.4%; mean difference, 9.6 percentage points; 95% confidence interval [CI], 5.7 - 13.5).

In contrast, visits due to edible cannabis more commonly involved acute psychiatric symptoms (18% vs 10.9%; mean difference, 7.1 percentage points; 95% CI, 2.1 - 12.1), intoxication (48.3% vs. 27.8%; mean difference, 20.5 percentage points; 95% CI, 13.9 - 27.1), and cardiovascular symptoms (8% vs 3.1%; mean difference, 4.9 percentage points; 95% CI, 1.4 - 8.4).

For patients using edible cannabis, the ED visits were also more likely to be shorter (2 hours vs 3 hours) and less likely to lead to hospitalization (18.9% vs 32.9%; P < .001) than they were for patients using inhalable cannabis.

The researchers also determined that, although edible cannabis accounted for just 0.32% of the states total cannabis sales (in kilograms of tetrahydrocannabinol [THC]) between 2014 and 2016, it was responsible for 10.7% of cannabis-related ED visits in Colorado during that period.

If inhalable and edible cannabis were equally toxic and resulted in the same number of ED visits, based on the study, 0.3% of cannabis-attributable visits would be due to use of edible products. The observed proportion of cannabis-attributable visits with edible exposure was about 33 times higher than expected (10.7% vs 0.32%) if both routes of exposure were equally toxic.

This data establishes that states considering cannabis legalization should take into account the relative toxicity of edible products. It may be best to limit edible products to medical indications in order to minimize pediatric exposures and mitigate the excessive rate of adult ED visits associated with these products. At the very least, users must be educated about the delayed kinetic profile and the increased risk for acute psychiatric and adverse cardiovascular events associated with edible ingestion.

Nora D. Volkow, MD, and Ruben Baler, PhD, from the National Institutes of Health, Bethesda, Maryland, highlight the important clinical and public health implications of these findings. There are several reasons why edible cannabis often leads to worse outcomes than inhalable cannabis. Because orally-ingested THC is absorbed more slowly than inhaled THC, people using the edible products find it harder to titrate the doses required to produce the desired effects. This is compounded by the slower clearance of orally-ingested THC from the body, which can result in accumulation in people who take extra doses in an attempt to achieve the desired drug effect more quickly.

In addition, the relatively harmless appearance of edibles and the variability in their labeling accuracy further contribute to overconsumption of these products.

Acknowledging that the complete range of potential adverse health consequences from cannabis consumption remain incompletely understood, the editorialists suggest that future research into the adverse effects of cannabis should focus on THC and content, route of administration, doses consumed, sex, age, body mass index, and the medical conditions for which it might be used.

The results of this recent study also underscore the urgent need for greater oversight of manufacturing practices, labeling standards, and quality control of cannabis products marketed to the public.

Ann Intern Med. Published online March 25, 2019.