Validation of the American Association of Poison Control Centers out of hospital guideline for pediatric diphenhydramine ingestions

Comparing N-acetylcysteine and 4-methylpyrazole as antidotes for acetaminophen overdose

Acetaminophen (APAP) overdose can cause hepatotoxicity and even liver failure. N-acetylcysteine (NAC) is still the only FDA-approved antidote against APAP overdose 40 years after its introduction. The standard oral or intravenous dosing regimen of NAC is highly effective for patients with moderate overdoses who present within 8 h of APAP ingestion. However, for late-presenting patients or after ingestion of very large overdoses, the efficacy of NAC is diminished. Thus, additional antidotes with an extended therapeutic window may be needed for these patients. Fomepizole (4-methylpyrazole), a clinically approved antidote against methanol and ethylene glycol poisoning, recently emerged as a promising candidate. In animal studies, fomepizole effectively prevented APAP-induced liver injury by inhibiting Cyp2E1 when treated early, and by inhibiting c-jun N-terminal kinase (JNK) and oxidant stress when treated after the metabolism phase. In addition, fomepizole treatment, unlike NAC, prevented APAP-induced kidney damage and promoted hepatic regeneration in mice. These mechanisms of protection (inhibition of Cyp2E1 and JNK) and an extended efficacy compared to NAC could be verified in primary human hepatocytes. Furthermore, the formation of oxidative metabolites was eliminated in healthy volunteers using the established treatment protocol for fomepizole in toxic alcohol and ethylene glycol poisoning. These mechanistic findings, together with the excellent safety profile after methanol and ethylene glycol poisoning and after an APAP overdose, suggest that fomepizole may be a promising antidote against APAP overdose that could be useful as adjunct treatment to NAC. Clinical trials to support this hypothesis are warranted.

(+)-Clausenamide protects against drug-induced liver injury by inhibiting hepatocyte ferroptosis

Drug-induced liver injury is the major cause of acute liver failure. However, the underlying mechanisms seem to be multifaceted and remain poorly understood, resulting in few effective therapies. Here, we report a novel mechanism that contributes to acetaminophen-induced hepatotoxicity through the induction of ferroptosis, a distinctive form of programmed cell death. We subsequently identified therapies protective against acetaminophen-induced liver damage and found that (+)-clausenamide ((+)-CLA), an active alkaloid isolated from the leaves of Clausena lansium (Lour.) Skeels, inhibited acetaminophen-induced hepatocyte ferroptosis both in vivo and in vitro. Consistently, (+)-CLA significantly alleviated acetaminophen-induced or erastin-induced hepatic pathological damages, hepatic dysfunctions and excessive production of lipid peroxidation both in cultured hepatic cell lines and mouse liver. Furthermore, treatment with (+)-CLA reduced the mRNA level of prostaglandin endoperoxide synthase 2 while it increased the protein level of glutathione peroxidase 4 in hepatocytes and mouse liver, confirming that the inhibition of ferroptosis contributes to the protective effect of (+)-CLA on drug-induced liver damage. We further revealed that (+)-CLA specifically reacted with the Cys-151 residue of Keap1, which blocked Nrf2 ubiquitylation and resulted in an increased Nrf2 stability, thereby leading to the activation of the Keap1–Nrf2 pathway to prevent drug-induced hepatocyte ferroptosis. Our studies illustrate the innovative mechanisms of acetaminophen-induced liver damage and present a novel intervention strategy to treat drug overdose by using (+)-CLA.

Substances Involved in Suicidal Poisonings in the United States

OBJECTIVE

This study investigated specific substances most commonly involved in suicidal poisonings, causing severe clinical effects, and leading to intensive treatments.

METHOD

Suicidal poisoning cases for individuals ≥13 years old were obtained from the National Poison Data System for 2011-2015. The most common products involved in single and multiple-product poisonings were identified. Single product cases were used to calculate substances causing the largest numbers of serious clinical effects and leading to intensive treatments.

RESULTS

More than half of reported cases involved only a single product (54.4%), but this frequency was higher at the extremes of age (66.7% in adolescents 13-19 years old and 70.5% in individuals ≥90 years old) and among pregnant women (65.8%). The top three substances involved in single-product poisonings were over-the-counter (OTC) medications, while alcohol and prescription sedatives were most common in multiple-product poisonings. One OTC medication, diphenhydramine, was a frequent cause of several serious clinical effects and intensive treatments.

CONCLUSIONS

Single product suicidal poisonings were more frequent with extremes of age and in pregnancy. OTC products were more frequently used in single product attempts. Products causing serious clinical effects can be targeted for suicide prevention efforts as well as education of health care providers.

Adolescent synthetic cannabinoid exposures reported to Texas poison centers

OBJECTIVE

This study describes the pattern of adolescent synthetic cannabinoid exposures reported to a large statewide poison center system.

METHODS

Synthetic cannabinoid exposures among patients younger than 20 years reported to Texas poison centers during January 2010 to June 2011 were identified. The distribution of exposures by various demographic and clinical factors was determined.

RESULTS

For 305 adolescent exposures, the mean age was 16.7 years (range, 12-19 y). The exposure was by inhalation in 77.4% of the cases, and 72.1% involved males. The exposure site was the patient's own residence in 70.5% of the cases, and a health care facility was the caller site in 68.9%. The patient was already at or en route to a health care facility in 80.3% of the cases, and the medical outcome was serious in 61.0%. The most frequently reported adverse clinical effects were tachycardia (41.6%), drowsiness/lethargy (24.3%), agitation/irritability (16.4%), vomiting (13.1%), hallucinations/delusions (11.5%), nausea (8.5%), confusion (8.2%), hypertension (7.5%), chest pain (6.9%), and dizziness/vertigo (5.2%).

CONCLUSIONS

Adolescent synthetic cannabinoid exposures reported to Texas poison centers were more likely to involve inhalation. The adolescents were more likely to be male. The exposures more often occurred at the patient's own residence and managed at a health care facility with a serious outcome. This pattern of exposures was similar to that observed among adults.

First European case of convulsions related to analytically confirmed use of the synthetic cannabinoid receptor agonist AM-2201

PURPOSE

There is increasing reported use of synthetic cannabinoid receptor agonists (SCRA) across Europe. To date, there is limited information on the acute toxicity (harm) related to the use of these products. We describe here a case in which an individual developed convulsions related to the use of the SCRA AM-2201.

CASE REPORT

A 20 year old male smoked a "Spice" (SCRA-containing) product called "Black Mamba," and rapidly after smoking, he had a generalised self-terminating tonic-clonic convulsion. After a 2 h observation period in the Emergency Department (ED), he self-discharged against medical advice. Subsequent analysis of urine collected at the time of presentation to the ED detected metabolites of AM-2201; no other drugs were detected on extensive analytic screening.

DISCUSSION

This is the first case of convulsions related to the use of SCRA described in Europe, and the first case of convulsions related to the use the SCRA AM-2201 confirmed by analysis of biological samples. It is important for emergency physicians, clinical toxicologists and clinical pharmacologists managing those presenting with acute toxicity related to the use of SCRA to analytically confirm the exact compound(s) involved, to enable accurate description of the acute toxicity associated with individual SCRA.

Convulsions associated with the use of a synthetic cannabinoid product

INTRODUCTION

Clinical presentations following the use of various "spice" or synthetic cannabinoids have included agitation, anxiety, emesis, hallucinations, psychosis, tachycardia, and unresponsiveness. Convulsions were described in a one report although there was not laboratory confirmation for synthetic cannabinoids. In another published report laboratory confirmation for a synthetic cannabinoid was done in which the patient manifested activity that was interpreted as a possible convulsion.

CASE REPORT

We describe a patient who had two witnessed generalized convulsions soon after smoking a "spice" product that we later confirmed to have four different synthetic cannabinoids.

DISCUSSION

Convulsions have only rarely been associated with marijuana exposures. Recreational use of synthetic cannabinoids is a very recent phenomenon and there is a very limited, albeit burgeoning, literature detailing the associated complications including convulsions we have reported here. The absence of anticonvulsant phytocannabinoids in spice products could potentially be one of multiple unknown mechanisms contributing to convulsions.

Synthetic cannabinoid exposures reported to Texas poison centers

Synthetic cannabinoid abuse is increasing in the United States. Synthetic cannabinoid exposures reported to Texas poison centers in 2010 were identified, and the distribution of exposures by selected factors was determined. There were 464 total cases. The number of exposures increased each month during January-July, then remained relatively constant for the next 5 months. The patients were 73.9% male and 57.3% were 20 years or older. Moderate or major effects or potentially toxic outcome occurred in 59.9% of the exposures. The most frequently reported clinical effects were tachycardia (37.3%), agitation (18.5%), drowsiness (18.5%), vomiting (15.7%), hallucinations (10.8%), and nausea (9.9%).