Glucagon-Like Peptide-1 Receptor Agonist Cases Reported to United States Poison Centers, 2017-2022

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are a class of medications for management of diabetes and obesity. The objective of this study is to characterize the epidemiology of GLP-1RA cases reported to US poison centers.

METHODS

We analyzed cases involving a GLP-1RA reported to the National Poison Data System during 2017-2022.

RESULTS

There were 5,713 single-substance exposure cases reported to US poison centers involving a GLP-1RA. Most cases were among females (71.3%) and attributable to therapeutic errors (79.9%). More than one-fifth (22.4%) of cases were evaluated in a healthcare facility, including 0.9% admitted to a critical care unit and 4.1% admitted to a non-critical care unit. Serious medical outcomes were described in 6.2% of cases, including one fatality. The rate of cases per one million US population increased from 1.16 in 2017 to 3.49 in 2021, followed by a rapid increase of 80.9% to 6.32 in 2022. Trends for rates of serious medical outcomes and admissions to a healthcare facility showed similar patterns with 129.9% and 95.8% increases, respectively, from 2021 to 2022.

CONCLUSIONS

Most GLP-1RA cases reported to US poison centers were associated with no or minimal effects and did not require referral for medical treatment; however, a notable minority of individuals experienced a serious medical outcome or healthcare facility admission. The rate of reported cases increased during the study period, including an 80.9% increase from 2021 to 2022. Opportunities exist to improve provider and patient awareness of the adverse effects of these medications.

Assessing the frequency and types of errors involved in the use of a modified intravenous N-acetylcysteine protocol for acetaminophen overdose

BACKGROUND

Acetaminophen overdose is a leading cause of acute liver failure in developing countries. N-acetylcysteine (NAC) is a highly effective antidote for acetaminophen hepatotoxicity, typically initiated in the emergency department. Due to a known high rate of errors with the standard three-bag IV NAC protocol, in 2019, the Ontario Poison Center changed to a modified 3% IV NAC one-bag protocol. This study was undertaken to determine the frequency and types of errors associated with the use of this protocol.

METHODS

Data were gathered via chart review of Ontario Poison Centre electronic medical record cases identified as receiving IV NAC for acetaminophen overdose between August 1 and September 30, 2022. 218 total charts were identified, and 188 were deemed eligible based on inclusion and exclusion criteria.

RESULTS

Errors were identified in 25% of charts, consisting of dosing errors in 11.7%, stopping errors in 9.0%, initiation errors in 3.7%, and interruptions in therapy in 3.2%. Dosing errors were the most common type of error (44.4%), with overdoses occurring three times more than underdoses. Errors were identified at 39% of geographic locations in the charts reviewed, with similar frequency in Ontario, Manitoba, and Nunavut. Clinical outcomes were similar in charts with and without errors.

INTERPRETATION

The rate of errors identified with this 3% IV NAC one-bag protocol is lower than reported for the standard three-bag protocol, but remains high due to dosing errors. Previously reported issues with prolonged interruptions in therapy with the standard three-bag protocol were low with the current 3% one-bag protocol. Although severe outcomes are rare, IV NAC overdose can be fatal. Identifying local factors in emergency departments that can contribute to administration errors (i.e., dose calculation, pump programming issues) can enhance the safety of this important antidote.

Fomepizole use reported to United States Poison Centers from 2010 to 2021

BACKGROUND

The diagnosis of toxic alcohol poisoning is often based on clinical presentation and nonspecific surrogate laboratory studies due to limited testing availability. Fomepizole is the recommended antidote and often administered empirically. The objective of this study is to identify substances that mimic toxic alcohols and compare key clinical factors between toxic alcohol and non-toxic alcohol exposures when fomepizole was administered.

METHODS

This study was a retrospective evaluation using the National Poison Data System from January 1, 2010 through December 31, 2021. Exposures were included if fomepizole was administered. Toxic alcohol exposures had ethylene glycol or methanol as a coded substance. For exposures not coded as a toxic alcohol, the first substance was described. Paracetamol (acetaminophen) exposures from 2020 and 2021 were excluded.

RESULTS

Fomepizole was reportedly used 25,110 times over 12 years. Use increased from 1,955 in 2010 to 2,710 in 2021. Most administrations were for reported toxic alcohol poisoning (60 percent) but use in reported non-toxic alcohol poisoning was greater starting in 2020. Toxic alcohol exposures were older (43.3 versus 39.8 years; P < 0.001) and more likely male (65.7 percent versus 58.2 percent). Level of care was mostly a critical care unit (67.7 percent), which was less common in toxic alcohol (63.3 percent) than non-toxic alcohol exposures (74.2 percent). The most common non-toxic alcohol substances were ethanol (24.9 percent) or an unknown drug (17.5 percent). Acidosis, increased creatinine concentration, anion gap, and osmolal gap, and kidney failure were coded in a lower proportion of toxic alcohol exposures than non-toxic alcohol exposures (P < 0.001).

DISCUSSION

The inability to provide rapid clinical confirmation of toxic alcohol poisoning results in the empiric administration of fomepizole to many patients who will ultimately have other diagnoses. Although fomepizole is relative well tolerated we estimated that this practice costs between $1.5 to $2.5 million. The major limitations of this work include the biases associated with retrospective record review, and the inability to confirm the exposures which may have resulted in allocation error.

CONCLUSION

Most fomepizole use was for a presumed toxic alcohol. This recently shifted to greater use in likely non-toxic alcohol poisoning. Key difference between the groups suggest fomepizole administration was likely due to the difficulty in diagnosis of toxic alcohol poisoning along with the efficacy and safety of fomepizole. Increased toxic alcohol laboratory testing availability could improve timely diagnosis, reserving fomepizole use for toxic alcohol poisoning.

Quenching thirst with poison? Paradoxical effect of anticancer drugs

Anticancer drugs have been developed with expectations to provide long-term or at least short-term survival benefits for patients with cancer. Unfortunately, drug therapy tends to provoke malignant biological and clinical behaviours of cancer cells relating not only to the evolution of resistance to specific drugs but also to the enhancement of their proliferation and metastasis abilities. Thus, drug therapy is suspected to impair long-term survival in treated patients under certain circumstances. The paradoxical therapeutic effects could be described as 'quenching thirst with poison', where temporary relief is sought regardless of the consequences. Understanding the underlying mechanisms by which tumours react on drug-induced stress to maintain viability is crucial to develop rational targeting approaches which may optimize survival in patients with cancer. In this review, we describe the paradoxical adverse effects of anticancer drugs, in particular how cancer cells complete resistance evolution, enhance proliferation, escape from immune surveillance and metastasize efficiently when encountered with drug therapy. We also describe an integrative therapeutic framework that may diminish such paradoxical effects, consisting of four main strategies: (1) targeting endogenous stress response pathways, (2) targeting new identities of cancer cells, (3) adaptive therapy- exploiting subclonal competition of cancer cells, and (4) targeting tumour microenvironment.

Topoisomerase I poison-triggered immune gene activation is markedly reduced in human small-cell lung cancers by impairment of the cGAS/STING pathway

BACKGROUND

Current immunotherapy strategies have contrasting clinical results in human lung cancer patients as small-cell lung cancers (SCLC) often show features of immunological cold tumours. Topoisomerase 1 (TOP1) poisons are effective antitumor drugs with good efficacy against lung cancers.

METHODS

We used molecular, genetic and bioinformatic approaches to determine the mechanism of micronuclei formation induced by two TOP1 poisons in different human cancer cells, including SCLC cell lines.

RESULTS

TOP1 poisons stimulate similar levels of micronuclei in all tested cell lines but downstream effects can vary markedly. TOP1 poisons increase micronuclei levels with a mechanism involving R-loops as overexpression of RNaseH1 markedly reduces or abolishes both H2AX phosphorylation and micronuclei formation. TOP1 poison-induced micronuclei activate the cGAS/STING pathway leading to increased expression of immune genes in HeLa cells, but not in human SCLC cell lines, mainly due to lack of STING and/or cGAS expression. Moreover, the expression of STING and antigen-presenting machinery genes is generally downregulated in patient tumours of human lung cancer datasets.

CONCLUSIONS

Altogether, our data reveal an immune signalling mechanism activated by TOP1 poisons, which is often impaired in human SCLC tumours.

Kratom exposures managed by the British Columbia poison centre, 2012-2019: a descriptive analysis

BACKGROUND

Kratom, a plant indigenous to Southeast Asia, which has been used both recreationally and in the treatment of pain and opioid dependence, has received little scrutiny in the United States and almost none in Canada. We analyzed calls to the British Columbia poison centre to describe caller-declared exposures to kratom and the acute health effects of these exposures.

METHODS

For this descriptive analysis, we accessed electronic records, including transcriptions and extracted variables, of calls specifying kratom exposure managed by the BC Drug and Poison Information Centre (DPIC) from 2012 to 2019. We describe changes in case numbers, reasons for exposure, concurrent drug exposures and clinical outcomes over the study period.

RESULTS

We identified 32 cases during the study period. In 23 cases (72%), the DPIC was consulted by a health care worker. Case numbers increased from 0 in 2012 to 9 in 2019. Numbers were highest for males in their 20s (n = 17, 53%). A total of 27 cases (84%) involved ingestion, with online distributors and local stores named as sources of procurement. A concurrent drug exposure was identified in 13 (41%) cases. There were no deaths; in 1 case, the exposed individual was intubated to manage agitation following kratom withdrawal.

INTERPRETATION

We observed a steady increase in kratom-related poison centre calls from 2012 to 2019, especially in young adult males. Rising call numbers may reflect increasing availability of kratom and may be a consequence of BC's opioid crisis, with kratom used by some to lessen symptoms of opioid withdrawal.

From Poison to Promise: The Evolution of Tetrodotoxin and Its Potential as a Therapeutic

Tetrodotoxin (TTX) is a potent neurotoxin that was first identified in pufferfish but has since been isolated from an array of taxa that host TTX-producing bacteria. However, determining its origin, ecosystem roles, and biomedical applications has challenged researchers for decades. Recognized as a poison and for its lethal effects on humans when ingested, TTX is primarily a powerful sodium channel inhibitor that targets voltage-gated sodium channels, including six of the nine mammalian isoforms. Although lethal doses for humans range from 1.5-2.0 mg TTX (blood level 9 ng/mL), when it is administered at levels far below LD₅₀, TTX exhibits therapeutic properties, especially to treat cancer-related pain, neuropathic pain, and visceral pain. Furthermore, TTX can potentially treat a variety of medical ailments, including heroin and cocaine withdrawal symptoms, spinal cord injuries, brain trauma, and some kinds of tumors. Here, we (i) describe the perplexing evolution and ecology of tetrodotoxin, (ii) review its mechanisms and modes of action, and (iii) offer an overview of the numerous ways it may be applied as a therapeutic. There is much to be explored in these three areas, and we offer ideas for future research that combine evolutionary biology with therapeutics. The TTX system holds great promise as a therapeutic and understanding the origin and chemical ecology of TTX as a poison will only improve its general benefit to humanity.

Fighting fire with fire: poisonous Chinese herbal medicine for cancer therapy

ETHNOPHARMACOLOGICAL RELEVANCE

Following the known principle of "fighting fire with fire", poisonous Chinese herbal medicine (PCHM) has been historically used in cancer therapies by skilled Chinese practitioners for thousands of years. In fact, most of the marketed natural anti-cancer compounds (e.g., camptothecin derivatives, vinca alkaloids, etc.) are often known in traditional Chinese medicine (TCM) and recorded as poisonous herbs as well. Inspired by the encouraging precedents, significant researches into the potential of novel anticancer drugs from other PCHM-derived natural products have been ongoing for several years and PCHM is increasingly being recognized as a gathering place for promising anti-cancer drugs. The present review aimed at giving a rational understanding of the toxicity of PCHM and, especially, providing the most recent developments on PCHM-derived anti-cancer compounds.

MATERIALS AND METHODS

Information on the toxicity and safety control of PCHM, as well as PCHM-derived anti-cancer compounds, was gathered from the articles, books and monographs published in the past 20 years.

RESULTS

Based on an objective introduction to the CHM toxicity, we clarified the general misconceptions about the safety of CHM and summarized the traditional experiences in dealing with the toxicity. Several PCHM-derived compounds, namely gambogic acid, triptolide, arsenic trioxide, and cantharidin, were selected as representatives, and their traditional usage and mechanism of anti-cancer actions were discussed.

CONCLUSIONS

Natural products derived from PCHM are of extreme importance in devising new drugs and providing unique ideas for the war against cancer. To fully exploit the potential of PCHM in cancer therapy, more attentions are advocated to be focused on their safety evaluation and mechanism exploration.

From poison to remedy: the chequered history of botulinum toxin

Botulinum toxin poisoning has afflicted mankind through the mists of time. However, the first incident of food-borne botulism was documented as late as the 18th century, when the consumption of meat and blood sausages gave rise to many deaths throughout the kingdom of Württemberg in South Western Germany. The district medical officer Justinus Kerner (1786--1862), who was also a well-known German poet, published the first accurate and complete descriptions of the symptoms of food-borne botulism between 1817 and 1822 and attributed the intoxication to a biological poison. Kerner also postulated that the toxin might be used for treatment purposes. In 1895, an outbreak of botulism in the small Belgian village of Ellezelles led to the discovery of the pathogen "Clostridium botulinum" by Emile Pierre van Ermengem. Modern botulinum toxin treatment was pioneered by Alan B. Scott and Edward J. Schantz in the early 1970s, when the type-A serotype was used in medicine to correct strabismus. Other preparations of the type-A toxin were developed and manufactured in the United Kingdom, Germany, and China, whereas a therapeutic type-B toxin was prepared in the United States. To date, the toxin has been used to treat a wide variety of conditions associated with muscular hyperactivity, glandular hypersecretions and pain.

Use of intramuscular botulinum toxin in Malaysian children with cerebral palsy

A study was carried out to determine the clinical effectiveness of intramuscular botulinum toxin type A (BTX) in the treatment of spasticity or dystonia in 58 consecutive children with cerebral palsy (CP). The effectiveness of the treatment was determined by the reduction of spasticity and global parental perception scale. The mean age of treatment was six years and the most frequent aim of treatment (91.1%) was functional improvement. The median reduction of spasticity as measured by modified Ashworth scale was 1. The short term outcome was graded as excellent or good by 44.6% and satisfactory by 38.4% of parents. Patients with dyskinetic Cerebral Palsy had the best response. Adverse effects were minimal. BTX treatment is modestly effective in the majority of our patients with spastic and dyskinetic cerebral palsy.

Randomized clinical trial of botulinum toxin plus glyceryl trinitrate vs. botulinum toxin alone for medically resistant chronic anal fissure: overall poor healing rates

PURPOSE

This study was designed to assess whether addition of glyceryl trinitrate to botulinum toxin improves the healing rate of glyceryl trinitrate-resistant fissures over that achieved with botulinum toxin alone.

METHODS

Patients were randomized between botulinum toxin plus glyceryl trinitrate (Group A) and botulinum toxin plus placebo paste (Group B). Patients were seen at baseline, four and eight weeks, and six months. The primary end point was fissure healing at eight weeks. Secondary end points were symptomatic relief, need for surgery, side effects, and reduction in maximum resting and squeeze pressures.

RESULTS

Thirty patients were randomized. Two-thirds of patients had maximum anal resting pressures below or within the normal range at entry to the study. Healing rates in both treatment groups were disappointing. There was a nonsignificant trend to better outcomes in Group A compared with Group B in terms of fissure healing (47 vs. 27 percent), symptomatic improvement (87 vs. 67 percent), and resort to surgery (27 vs. 47 percent).

CONCLUSIONS

There is some evidence to suggest that combining glyceryl trinitrate with botulinum toxin is superior to the use of botulinum toxin alone for glyceryl trinitrate-resistant anal fissure. The poor healing rate may reflect the fact that many of the patients did not have significant anal spasm at trial entry.

Pharmacology of botulinum toxin: differences between type A preparations

Different types of botulinum neurotoxin (BoNT) block different proteins of the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) protein complex within cholinergic nerve terminals, producing blockade of cholinergic neuromuscular and autonomic synapses. Animal studies indicate the longest duration of action for BoNT type A (BoNTA) followed by types B, F, and E. Diffusion to adjacent and remote muscles may be related to protein composition, dilutions, volume, target muscle selection, and injection technique. A review of head-to-head, randomized, controlled trials of BoNTA preparations (Botox and Dysport) suggests that Dysport tends to have higher efficacy, longer duration, and higher frequency of adverse effects. Conversion factors between the preparations varied, however, and remain controversial. In clinical settings, a Botox:Dysport conversion ratio of 1:3 may be appropriate. Animal studies suggest a conversion ratio of 1:2.5-3. When therapeutic effects between these preparations are attempting to be equalized, Dysport seems to produce more adverse effects. In mice, Botox appears to have a better safety margin than Dysport and BoNTB. In rats, diffusion margins are similar for Botox and Dysport. Jitter derived from stimulation single-fiber EMG of injected and remote muscles show no differences between Botox and Dysport. Atrophy of extrafusal muscle fibers of injected and remote muscles do not differ between the BoNTA preparations.

Biologic poisons for pain

Pain therapies from natural sources date back thousands of years to the use of plant and animal extracts for a variety of painful conditions and injuries. We certainly are all familiar with modern uses of plant-derived analgesic compounds such as opium derivatives from papaverum somniferum and salicylates from willow bark (Salix species). Local anesthetics were isolated from coca leaves in the late 1800s. Sarapin, derived from carnivorous pitcher plants, has been injected for regional analgesia in human and veterinary medicine, but efficacy is controversial. Biologic organisms can play important roles in developing an understanding of pain mechanisms, either from isolation of compounds that are analgesic or of compounds that produce pain, hyperalgesia, and allodynia.

Toxic effects of arsenic (As3+) and other metal ions on acute promyelocytic leukemia cells

Since arsenic compounds reportedly induced complete remission in patients with acute promyelocytic leukemia (APL) in China, we studied the in vitro effect of metal ions including As3+, As5+, Cd2+, Ga3+, Ge4+, Hg2+, Se4+, and Zn2+ on myeloid cell lines. One-tenth microM As3+ caused growth suppression and morphological changes resembling differentiation in NB4 cells, but did not induce the maturation-markers, CD11b, CD14 and NBT-reductase. More than 1 microM As3+ caused the time- and dose-dependent apoptosis of NB4 cells. Other metal ions at the same concentrations induced neither morphological changes nor apoptosis in myeloid cell lines including NB4, whereas Cd2+, Ga3+, and Hg2+ induced moderate and non-specific growth suppression. All-trans retinoic acid (ATRA)-resistant NB4 cells were similarly sensitive to As3+. Among the clinical leukemia samples, As3+ was selectively toxic to APL cells regardless of ATRA-sensitivity. These findings suggest that APL cells are sensitive to As3+, and that As3+ acts on APL cells via a different pathway than ATRA.