Adverse events associated with pediatric exposures to dextromethorphan

Prospective multicenter study of the epidemiological features of emergency patients with overdose of over-the-counter drugs in Japan

Aim

To investigate the epidemiological characteristics of patients presenting to the emergency department with an overdose of over-the-counter (OTC) drugs.

Methods

A questionnaire survey was conducted to examine the sociodemographic characteristics of patients with OTC drugs overdoses visiting emergency departments at eight sites across the country. The patients were divided into "habitual" and "nonhabitual" groups according to their history of OTC drugs overdose. Student's t-test or Welch's t-test was performed for numerical variables, and Pearson's χ 2 test was performed for dichotomous and nominal variables between the two groups.

Results

Of the 124 patients included in this study, 79% were women. The habitual (26.6%) and the nonhabitual (73.4%) groups showed no differences in sex, occupation, cohabitants, history of mental illness, or history of alcohol consumption or smoking; however, those in the habitual group were significantly younger. The proportion of OTC drugs obtained from physical stores was higher in the habitual group, whereas the nonhabitual group used more household medicines. Suicide and self-harm were more common reasons for overdose in the nonhabitual group. Antipyretic analgesics were significantly more common in the nonhabitual group, whereas antitussive expectorants and antihistamines were significantly more common in the habitual group.

Conclusion

This is the first multicenter study to determine the status of OTC drugs overdose patients treated at emergency departments of medical facilities in Japan. To prevent new overdoses of OTC drugs, continued detailed epidemiologic studies of patient backgrounds and drug acquisition routes, and investigation of the components of OTC drugs that cause dependency are necessary.

Clinical Toxicology of OTC Cough and Cold Pediatric Medications: A Narrative Review

Cough and cold symptoms (CCS) are common pediatric conditions often treated with over-the-counter (OTC) medications. However, the available knowledge regarding the safety and toxicity of these medications in children is inadequate. Therefore, understanding their clinical toxicology is crucial for safeguarding children's well-being. This narrative review highlights the importance of clinical toxicology in evaluating the safety and toxicity profile of OTC medications for treating CCS in pediatric patients. The pharmacology, clinical features, and adverse effects of various drug classes commonly found in cough and cold medications are briefly discussed. Pharmacokinetic and pharmacodynamic parameters are also examined to understand the interactions between these drugs and the body. OTC cough and cold medications often contain active ingredients such as antihistamines, decongestants, antitussives, expectorants, and analgesics-antipyretics. The combination of multiple ingredients in these products significantly increases the risk of adverse effects and unintentional overdoses. Several case studies have reported significant toxicity and even fatalities associated with the use of these medications in children. This review underscores the critical importance of clinical toxicology in evaluating the safety and toxicity profile of OTC medications employed for treating CCS in pediatric patients. The findings highlight the significance of informed clinical practice and public health policies to ensure the well-being of children using OTC cough and cold medications.

The N-Methyl-D-Aspartate Receptor Antagonist Dextromethorphan Improves Glucose Homeostasis and Preserves Pancreatic Islets in NOD Mice

For treatment of type 1 diabetes mellitus, a combination of immune-based interventions and medication to promote beta-cell survival and proliferation has been proposed. Dextromethorphan (DXM) is an N-methyl-D-aspartate receptor antagonist with a good safety profile, and to date, preclinical and clinical evidence for blood glucose-lowering and islet-cell-protective effects of DXM have only been provided for animals and individuals with type 2 diabetes mellitus. Here, we assessed the potential anti-diabetic effects of DXM in the non-obese diabetic mouse model of type 1 diabetes. More specifically, we showed that DXM treatment led to five-fold higher numbers of pancreatic islets and more than two-fold larger alpha- and beta-cell areas compared to untreated mice. Further, DXM treatment improved glucose homeostasis and reduced diabetes incidence by 50%. Our data highlight DXM as a novel candidate for adjunct treatment of preclinical or recent-onset type 1 diabetes.

Life-threatening pediatric dextromethorphan polistirex overdose

Dextromethorphan polistirex is an extended-release formulation of dextromethorphan hydrobromide, marketed as Delsym® (Reckitt; Parsippany, NJ), with a duration of action roughly two to three times that of the standard formulation. The polistirex binder is responsible for the prolonged duration of action by slowing the release of active ingredient; the liberated dextromethorphan has unchanged pharmacokinetics and clinical effects. A 23-month-old male presented following a 900 mg (71.4 mg/kg) dextromethorphan polistirex ingestion 90 min prior. On arrival, he was unresponsive, tachycardic, and hypertensive with mydriasis, roving eye movements, rotary nystagmus, and opisthotonos. Approximately 90 min after arrival, he required intubation for airway protection. The blood dextromethorphan concentration from 75 min after arrival was 110 ng/mL (10-40 ng/ml therapeutic). He was extubated approximately 13 h after arrival and discharged that day. Most pediatric dextromethorphan overdoses produce mild symptoms that are not considered to be life-threatening. Life threatening overdoses are rare. The toxic dextromethorphan dose and blood concentration as well as the toxicokinetics of the polistirex formulation are not well defined. Our case suggests that a blood dextromethorphan concentration exceeding 100 ng/mL can be toxic in this age group, however further study is needed.

Caregiver Reports of Infant Distress and Injury in Abused Infants

OBJECTIVES

To determine whether in infants evaluated for physical abuse, medical encounters for infant distress are correlated with physical abuse or a history of sentinel injuries.

STUDY DESIGN

This retrospective, case-control analysis of infants aged <12 months evaluated for physical abuse identified demographic characteristics, prior injuries, and medical encounters for infant distress. Variables were compared between abused infants and nonabused infants with and without sentinel injuries. A nonparametric recursive classification tree analysis assessed interactions between variables.

RESULTS

Infant distress was associated with abuse (67.9% vs 44.7%; P = .008; OR, 2.6; 95% CI, 1.3-5.2). Infants with sentinel injuries had higher rates of infant distress (74.1% vs 42.4%; P ≤ .001) and crying (81.5% vs 62.7%; P = .012). Previous falls (32.6% vs 18.1%; P = .03) and nonsentinel injuries (18.2% vs 5.4%; P = .002) also were associated with abuse, although sentinel injuries were the most important predictor of abuse, followed by infant distress.

CONCLUSIONS

Infants with medical encounters for distress and injury may be at higher risk for abuse and may benefit from intensive educational and support services for their caregivers. Additional research evaluating the most effective interventions for caregivers of fussy infants is needed.

Infant dextromethorphan and dextrorphan exposure via breast milk from mothers who are CYP2D6 extensive metabolizers

The risk of infant exposure to dextromethorphan (DM) and its active metabolite, dextrorphan (DX), through breast milk has not been evaluated. In this study, bound and unbound DM and DX concentrations in breast milk and plasma at 2 h post-dose were measured in 20 lactating women (n = 20) following a single 30 mg oral dose of DM. The DM and DX concentrations in breast milk were positively correlated with their respective plasma concentrations. The breast milk-to-plasma (M/P) ratios of 1.0 and 1.6 and the unbound M/P ratios of 1.1 and 2.0 for DM and DX, respectively, suggested that DM and DX are extensively distributed into breast milk. The infant exposure following a single dose of 30 mg DM was estimated using the breast milk concentrations to be 0.33 ± 0.32 μg/kg/day and 1.8 ± 1.0 μg/kg/day for DM and DX, respectively. The steady-state infant exposure was estimated using the M/P ratios and previously reported AUC of DM and DX following repeated dosing of DM 60 mg orally twice daily to be 0.64 ± 0.22 μg/kg/day and 1.23 ± 0.38 μg/kg/day, respectively. Based on these estimated infant doses, the relative infant doses (RIDs) were estimated to be <1%, suggesting the infant is only exposed to a minor fraction of adult dose through breast milk; however, one nursing infant developed an erythematous rash during this study which warrants additional research to fully elucidate the risks of infant exposure to DM and DX through breast milk. This article is protected by copyright. All rights reserved.

Dextromethorphan - A widely-used cough suppressant - Induces local anaphylaxis via MRGPRX2 on mast cells

Dextromethorphan (DM) is a cough suppressant available in many prescribed and over-the-counter medications. Adverse reactions induced by DM have been regularly reported, including allergic skin reactions in some cases. However, the underlying mechanisms of local anaphylaxis induced by DM have not been elucidated. In this study, we found that DM could activate mast cells to increase calcium mobilization and release β-hexosaminidase, histamine, tumor necrosis factor-α, MCP-1, and IL-8 in a dose-dependent manner. The allergic reactions were confirmed by hind paw swelling and extravasation assay in vivo. Furthermore, DM was revealed to induce local anaphylaxis via MRGPRX2 by the mast cell-deficient kit^W-sh/W-sh mice and MRGPRX2 knockdown mast cells. And the MRGPRX2-HEK293/CMC analysis and frontal analysis also showed that DM has a considerable affinity with MRGPRX2. Together, our findings suggest that close monitoring should be drawn on patients with DM for its potential anaphylaxis via MRGPRX2.

Honey and children: only a grandma's panacea or a real useful tool?

Honey is a natural product that has been used as medication since the ancient times for its nutritive and therapeutic value. Despite these properties, honey use has been limited in evidence-based medicine due to the lack of evidence in clinical settings, particularly in paediatric population. An increasing interest has grown towards honey during the last years. The aim of this article is to examine the possible role of honey as a therapeutic tool in paediatrics. We performed a literature search to summarise the highest quality evidences, analysed articles regarding honey's nutritional properties and therapeutic value. The state of the art is represented by evidences related to beneficiary effects of honey on respiratory, gastroenterological and oncohaematologic diseases. Many other uses could promisingly come from in vitro studies or clinical trial based on adult samples. Honey shows an excellent risk-benefit profile and can be safely administrated in children older than 12 months. In conclusion, honey does not only represent a grandma's remedy, but is a real useful tool in different clinical settings, including paediatrics practice. However, there is a need for high-quality, large randomised controlled trials confirming effectiveness and practical application of honey in paediatric population.

Adverse events associated with diphenhydramine in children, 2008-2015

Introduction: Diphenhydramine (DPH) exposures in children may be the result of accidental unsupervised ingestions, caregiver error, and intentional misuse of DPH-containing cough and cold medications (CCM). We sought to understand the nature of pediatric ingestions of DPH, particularly the toxicity and outcome of a single product, single ingredient DPH (DPH-only) exposures, in order to derive ingredient-specific information about the clinical effects and course of such cases.Methods: As part of a U.S. multi-year safety surveillance program to assess the safety of over-the-counter (OTC) medications used in cough and cold preparations in children <12 years of age, an expert panel reviewed cases involving symptomatic adverse events potentially related to oral exposures to these medications. After individual review, the cases were categorized by causal relationship of the reported ingredients to the adverse event, exposure intent (therapeutic, non-therapeutic, unknown intent), and dose (therapeutic, supratherapeutic, or unknown). Following panel review, any disagreement on classification was discussed until a consensus was reached. The data were then analyzed with respect to descriptive findings.Results: The panel reviewed 6618 eligible cases and determined 2802 were at least potentially related to oral exposure to DPH. Of these, 2028 were DPH-only cases (39.1% of all cases judged at least potentially related to a cough and cold medication). The majority (79.5%) of DPH-only cases occurred in children 2 to <4 years of age and involved accidental unsupervised ingestions (74.7%). Liquid pediatric formulations were the most common (51.7%) products reported followed by solid pediatric formulations (24.0%). The most common adverse events were tachycardia (53.4%), hallucinations (46.5%), somnolence (34.7%), agitation (33.9%), and mydriasis (26.3%). Seizures occurred in only 5.5% of cases. Five (0.2%) deaths were reported; in the death cases, the DPH dose was judged supratherapeutic in one and unknown in the other four. Child abuse was reported in four of the five death cases and three of the five deaths were homicides.Conclusions: Exposures to DPH-only products were the most common type of exposure detected in our study of adverse events associated with CCM in children. The majority of the DPH-only cases were the result of accidental unsupervised ingestions. Most adverse events were relatively mild self-limited anticholinergic effects and few deaths occurred. Deaths involving DPH were often associated with child abuse or homicide. Interventions targeting the prevention of accidental unsupervised are likely to be impactful in preventing morbidity associated with DPH-only exposure.

Adverse events associated with opioid-containing cough and cold medications in children

BACKGROUND

Until recently most of the scrutiny of opioid-containing cough and cold medications (CCMs) by the US Food and Drug Administration (FDA) was focused on codeine, only recently shifting equal focus to those containing hydrocodone. We characterized adverse events (AEs) in children <12 years old associated with CCMs that include both an opioid and over-the-counter (OTC) ingredient.

METHODS

US cases from multiple sources collected as part of a safety surveillance program were included if AEs followed exposure to combination CCMs containing codeine or hydrocodone between January 2008 and December 2015. An expert panel reviewed cases to identify causal relationship between exposure and AEs and identify contributing factors. Each AE term was coded using the Medical Dictionary for Regulatory Activities with preferred terms reported.

RESULTS

One hundred and fourteen of the 7035 (2%) cases reviewed involved an opioid-containing product. Ninety-eight cases involved an AE at least potentially related to the opioid ingredient (38 (39%) codeine; 60 (61%) hydrocodone). All three fatality cases involved hydrocodone with an antihistamine. Among non-fatalities, somnolence, lethargy, and/or respiratory depression were more commonly reported among hydrocodone cases than codeine cases (86% vs. 61%; p = .005).

DISCUSSION

These safety surveillance data support the FDA's expanded label changes limiting opioid CCMs for children.

Pediatric Iatrogenic Movement Disorders

The acute development of a movement disorder is often a dramatic and frightening experience for patients and families, often requiring urgent or emergent evaluation by a neurologist. In the assessment of these patients, one relies on the history, physical and neurologic examination to determine the etiology of the condition. We aim to demonstrate that a thorough medication history is an incredibly critical part of this evaluation as iatrogenic movement disorders can arise from exposure not only to psychoactive medications, but from drugs prescribed for a variety of nonneurologic disorders. This comprehensive review is organized by movement disorder semiology so that the reader can more readily develop a differential diagnosis when evaluating a patient with a movement disorder.