Prospective evaluation of mild to moderate pediatric acetaminophen exposures

Paracetamol (acetaminophen) use in infants and children was never shown to be safe for neurodevelopment: a systematic review with citation tracking

Although widely believed by pediatricians and parents to be safe for use in infants and children when used as directed, increasing evidence indicates that early life exposure to paracetamol (acetaminophen) may cause long-term neurodevelopmental problems. Furthermore, recent studies in animal models demonstrate that cognitive development is exquisitely sensitive to paracetamol exposure during early development. In this study, evidence for the claim that paracetamol is safe was evaluated using a systematic literature search. Publications on PubMed between 1974 and 2017 that contained the keywords "infant" and either "paracetamol" or "acetaminophen" were considered. Of those initial 3096 papers, 218 were identified that made claims that paracetamol was safe for use with infants or children. From these 218, a total of 103 papers were identified as sources of authority for the safety claim.   Conclusion: A total of 52 papers contained actual experiments designed to test safety, and had a median follow-up time of 48 h. None monitored neurodevelopment. Furthermore, no trial considered total exposure to drug since birth, eliminating the possibility that the effects of drug exposure on long-term neurodevelopment could be accurately assessed. On the other hand, abundant and sufficient evidence was found to conclude that paracetamol does not induce acute liver damage in babies or children when used as directed. What is Known: • Paracetamol (acetaminophen) is widely thought by pediatricians and parents to be safe when used as directed in the pediatric population, and is the most widely used drug in that population, with more than 90% of children exposed to the drug in some reports. • Paracetamol is known to cause liver damage in adults under conditions of oxidative stress or when used in excess, but increasing evidence from studies in humans and in laboratory animals indicates that the target organ for paracetamol toxicity during early development is the brain, not the liver. What is New: • This study finds hundreds of published reports in the medical literature asserting that paracetamol is safe when used as directed, providing a foundation for the widespread belief that the drug is safe. • This study shows that paracetamol was proven to be safe by approximately 50 short-term studies demonstrating the drug's safety for the pediatric liver, but the drug was never shown to be safe for neurodevelopment. Paracetamol is widely believed to be safe for infants and children when used as directed, despite mounting evidence in humans and in laboratory animals indicating that the drug is not safe for neurodevelopment. An exhaustive search of published work cited for safe use of paracetamol in the pediatric population revealed 52 experimental studies pointing toward safety, but the median follow-up time was only 48 h, and neurodevelopment was never assessed.

Case Report: Paracetamol Poisoning in a 2-Year-Old Child – from International Overview to the Role of the Hong Kong Poison Information Centre

We report a 2-year-old girl suffering from acute liver failure as a result of paracetamol poisoning. The child successfully recovered after intensive care. We performed literature search for the past decade and found that the pathophysiological response in the child was different from that of the adult. Despite paracetamol poisoning being one of the most common poisonings in the world, there is still no consensus in the treatment protocol. Hence the role of the Hong Kong Poison Information Centre is briefly discussed.

Acute Liver Failure following Cleft Palate Repair: A Case of Therapeutic Acetaminophen Toxicity

Background

Acetaminophen is a widely used analgesic and antipyretic agent in the pediatric population. While the hepatotoxic effects of the drug have been well recognized in cases of acute overdose and chronic supratherapeutic doses, the toxic effects of acetaminophen are rarely documented in cases where therapeutic guidelines are followed.

Case

An 8-month-old boy underwent cleft palate repair and placement of bilateral myringotomy tubes. His anesthetic course was uneventful, consisting of maintenance with desflurane and fentanyl. He received acetaminophen for routine postoperative pain management and was tolerating liquids and discharged home on postoperative day 1. On day 3, the child was profoundly lethargic with multiple episodes of emesis and was taken to the emergency department. He suffered a 45-second tonic-clonic seizure in transport to the regional children's medical center, and initial laboratory results demonstrated acute hepatitis with AST 24,424 U/L, ALT 12,885 U/L, total bilirubin 3.1 mg/dL, and a serum acetaminophen level of 83 μg/mL. Aggressive supportive measures including blood products and periprocedural fresh frozen plasma, piperacillin/tazobactam, and intravenous infusions of N-acetylcysteine, sodium phenylacetate and sodium benzoate, carnitine, and citrulline were administered. His metabolic acidosis and acute hepatitis began to correct by day 4, and he was discharged home without further surgical intervention on day 15.

Conclusion

Although acetaminophen is an effective and commonly used analgesic in pediatric practice, hepatotoxicity is a potentially devastating complication. This report challenges the appropriateness of existing guidelines for acetaminophen administration and emphasizes the importance of close follow-up and hydration after even relatively minor surgery.

A review of acetaminophen poisoning

Acetaminophen poisoning remains one of the more common drugs taken in overdose with potentially fatal consequences. Early recognition and prompt treatment with N-acetylcysteine can prevent hepatic injury. With acute overdose, the Rumack-Matthew nomogram is a useful tool to assess risk and guide management. Equally common to acute overdose is the repeated use of excessive amounts of acetaminophen. Simultaneous ingestion of several different acetaminophen-containing products may result in excessive dosage. These patients also benefit from N-acetylcysteine. Standard courses of N-acetylcysteine may need to be extended in patients with persistently elevated plasma concentrations of acetaminophen or with signs of hepatic injury.

Systematic review and meta-analysis of the clinical safety and tolerability of ibuprofen compared with paracetamol in paediatric pain and fever

OBJECTIVE

The main aim of this review was to compare the tolerability and safety between ibuprofen and paracetamol when used as anti-pyretic and analgesic agents in children up to 18 years of age.

METHODS

MEDLINE (1950 to November 2008), EMBASE (1980 to November 2008), The Cochrane Library (2007, Issue 3), ACP Journal Club (1991 to November 2007) and Pascal (1987 to November 2007) were searched for randomised controlled trails (RCTs) (comparing ibuprofen and/or paracetamol with placebo), controlled observational studies and large case series comprised more than 1000 participants.

MAIN OUTCOME MEASURES

Adverse events (AEs) requiring discontinuation of medication; systemic reactions related to ibuprofen or paracetamol; serious AEs that are fatal, life-threatening or require hospitalisation; and serious AEs not requiring hospitalisation.

RESULTS

A total of 24 RCTs examined either ibuprofen and/or paracetamol versus placebo for AE data. Twelve other studies meeting our criteria were also included for AE data. Meta-analysis of systemic reactions demonstrated that tolerability and safety of ibuprofen was similar to placebo, as was paracetamol: ibuprofen versus placebo relative risk (RR) 1.39 (95% CI: 0.92, 2.10); paracetamol versus placebo RR 1.57 (95% CI 0.74, 3.33). A total of 2937 systemic AEs occurred in 21,305 patients taking ibuprofen compared with 1,466 systemic AEs in 11,164 patients taking paracetamol: RR 1.03 (95% CI 0.98, 1.10). There was no significant difference between the two groups. Narrative analysis of AE data identified conflicting evidence regarding hepatic injury with paracetamol and group A streptococcal infections with ibuprofen or paracetamol treatment.

CONCLUSIONS

Ibuprofen, paracetamol and placebo have similar tolerability and safety profiles in terms of gastrointestinal symptoms, asthma and renal adverse effects. While the study data investigated here may not reflect over-the-counter use, these results are still relevant in the context of any safety concerns relating to general ibuprofen or paracetamol treatment in children.

Acute liver failure in children

OBJECTIVE

To review the incidence, etiologies, pathophysiology, and treatment of acute liver failure (ALF) in children. Emphasis will be placed on the initial management of the multiple organ system involvement of ALF.

METHOD

MEDLINE search from 1970 to March 2005 was performed. Search headings were as follows: acute liver failure, fulminant liver failure, pediatric liver failure, hepatic encephalopathy, and liver transplantation. Studies written in English were selected. Pediatric studies were emphasized. Adult studies were referenced if there were no pediatric studies available in regard to a specific aspect of liver failure.

CONCLUSIONS

Pediatric acute liver failure is a rare but life-threatening disease. The common etiologies differ for given age groups. Management includes treating specific causes and supporting multiple organ system failure. Commonly associated disorders that require initial recognition and treatment include energy production deficiencies (hypoglycemia), coagulation abnormalities, immune system dysfunctions, encephalopathy, and cerebral edema. Criteria used to determine the need for liver transplant are reviewed as well as the difficulties associated with predicting which patients will meet these criteria and how rapidly liver transplant will become the only option. Finally, experimental procedures that may provide additional time for the liver to recover are briefly reported.

Paracetamol induced hepatotoxicity

AIM

To identify the clinical and biochemical risk factors associated with outcome of paracetamol induced significant hepatotoxicity in children.

METHODS

Retrospective case notes review of those with paracetamol overdose admitted from 1992 to 2002. Patients were analysed in two groups: group I recovered after conservative treatment and group II developed progressive liver dysfunction and were listed for liver transplantation.

RESULTS

Of 51 patients (6 males, 45 females, aged 0.8-16.1 years), 6 (aged <7 years) received cumulative multiple doses, and 45 a single large overdose (median 345 mg/kg, range 91-645). The median (range) interval to hospital at presentation post-ingestion was 24 hours (4-65) and 44 hours (24-96) respectively in groups I and II. Patients received standard supportive treatment including N-acetylcysteine. All children in group I survived. In group II, 6/11 underwent orthotopic liver transplantation (OLT) and 2/6 survived; 5/11 died awaiting OLT. Cerebral oedema was the main cause of death. Children who presented late to hospital for treatment and those with progressive hepatotoxicity with prothrombin time >100 seconds, hypoglycaemia, serum creatinine >200 micromol/l, acidosis (pH <7.3), and who developed encephalopathy grade III, had a poor prognosis or died. Although hepatic transaminase levels were markedly raised in both groups, there was no correlation with necessity for liver transplantation or death.

CONCLUSION

Accidental or incidental paracetamol overdose in children may be associated with toxic liver damage leading to fulminant liver failure. Delayed presentation and/or delay in treatment, and hepatic encephalopathy > or =grade III were significant risk factors, implying poor prognosis and need for OLT. Prompt identification of high risk patients, referral to a specialised unit for management, and consideration for liver transplantation is essential.

Emergency visits for childhood poisoning: a 2-year prospective multicenter survey in Spain

OBJECTIVES

To describe the characteristics of childhood poisoning leading to consultation to 17 pediatric emergency departments in Spain.

METHODS

During a 2-year period (January 2001 to December 2002), accompanying people of 2157 children with acute intoxication who visited consecutively at the emergency room were prospectively surveyed.

RESULTS

Childhood poisoning accounted for 0.28% of all emergency visits during the study period. The median (interquartile range, 25th-75th percentile) age was 24 months (22-60 months); 67% of children were younger than 4 years. Drug ingestion was involved in 54.7% of cases (paracetamol was the most frequent drug), domestic products in 28.9%, alcohol in 5.9%, carbon monoxide in 4.5%, and illicit drugs in 1.5%. A total of 61.3% of patients were admitted within 1 hour after exposure to the toxic substance, and 10.3% had been already treated before arrival; 29.1% of patients were referred for clinical manifestations which were mostly neurological symptoms. Laboratory tests and other investigations were performed in 40.7% of cases. Gastrointestinal decontamination was used in 51.7% of patients, with activated charcoal in 32.3%. Treatment varied significantly according to the individual hospitals. A total of 83.3% of patients were treated as outpatients, 15.2% were hospitalized, and 1.5% were admitted to the intensive care unit. One 11-month-old boy with carbon monoxide intoxication died. Six patients had permanent sequelae (esophageal stenosis in 5 and partial blindness in 1).

CONCLUSIONS

Young children who accidentally ingested drugs and, less frequently, domestic products accounted for most cases of intoxication who presented at the pediatric emergency department.

Acetaminophen poisoning: an evidence-based consensus guideline for out-of-hospital management

The objective of this guideline is to assist poison center personnel in the appropriate out-of-hospital triage and initial management of patients with suspected ingestions of acetaminophen. An evidence-based expert consensus process was used to create this guideline. This guideline applies to ingestion of acetaminophen alone and is based on an assessment of current scientific and clinical information. The expert consensus panel recognizes that specific patient care decisions may be at variance with this guideline and are the prerogative of the patient and the health professionals providing care. The panel's recommendations follow. These recommendations are provided in chronological order of likely clinical use. The grade of recommendation is provided in parentheses. 1) The initial history obtained by the specialist in poison information should include the patient's age and intent (Grade B), the specific formulation and dose of acetaminophen, the ingestion pattern (single or multiple), duration of ingestion (Grade B), and concomitant medications that might have been ingested (Grade D). 2) Any patient with stated or suspected self-harm or who is the recipient of a potentially malicious administration of acetaminophen should be referred to an emergency department immediately regardless of the amount ingested. This referral should be guided by local poison center procedures (Grade D). 3) Activated charcoal can be considered if local poison center policies support its prehospital use, a toxic dose of acetaminophen has been taken, and fewer than 2 hours have elapsed since the ingestion (Grade A). Gastrointestinal decontamination could be particularly important if acetylcysteine cannot be administered within 8 hours of ingestion. Acute, single, unintentional ingestion of acetaminophen: 1) Any patient with signs consistent with acetaminophen poisoning (e.g., repeated vomiting, abdominal tenderness in the right upper quadrant or mental status changes) should be referred to an emergency department for evaluation (Grade D). 2) Patients less than 6 years of age should be referred to an emergency department if the estimated acute ingestion amount is unknown or is 200 mg/kg or more. Patients can be observed at home if the dose ingested is less than 200 mg/kg (Grade B). 3) Patients 6 years of age or older should be referred to an emergency department if they have ingested at least 10 g or 200 mg/kg (whichever is lower) or when the amount ingested is unknown (Grade D). 4) Patients referred to an emergency department should arrive in time to have a stat serum acetaminophen concentration determined at 4 hours after ingestion or as soon as possible thereafter. If the time of ingestion is unknown, the patient should be referred to an emergency department immediately (Grade D). 5) If the initial contact with the poison center occurs more than 36 hours after the ingestion and the patient is well, the patient does not require further evaluation for acetaminophen toxicity (Grade D). Repeated supratherapeutic ingestion of acetaminophen (RSTI): 1) Patients under 6 years of age should be referred to an emergency department immediately if they have ingested: a) 200 mg/kg or more over a single 24-hour period, or b) 150 mg/kg or more per 24-hour period for the preceding 48 hours, or c) 100 mg/kg or more per 24-hour period for the preceding 72 hours or longer (Grade C). 2) Patients 6 years of age or older should be referred to an emergency department if they have ingested: a) at least 10 g or 200 mg/kg (whichever is less) over a single 24-hour period, or b) at least 6 g or 150 mg/kg (whichever is less) per 24-hour period for the preceding 48 hours or longer. In patients with conditions purported to increase susceptibility to acetaminophen toxicity (alcoholism, isoniazid use, prolonged fasting), the dose of acetaminophen considered as RSTI should be greater than 4 g or 100 mg/kg (whichever is less) per day (Grade D). 3) Gastrointestinal decontamination is not needed (Grade D). Other recommendations: 1) The out-of-hospital management of extended-release acetaminophen or multi-drug combination products containing acetaminophen is the same as an ingestion of acetaminophen alone (Grade D). However, the effects of other drugs might require referral to an emergency department in accordance with the poison center's normal triage criteria. 2) The use of cimetidine as an antidote is not recommended (Grade A).

Acute poisoning: understanding 90% of cases in a nutshell

The acutely poisoned patient remains a common problem facing doctors working in acute medicine in the United Kingdom and worldwide. This review examines the initial management of the acutely poisoned patient. Aspects of general management are reviewed including immediate interventions, investigations, gastrointestinal decontamination techniques, use of antidotes, methods to increase poison elimination, and psychological assessment. More common and serious poisonings caused by paracetamol, salicylates, opioids, tricyclic antidepressants, selective serotonin reuptake inhibitors, benzodiazepines, non-steroidal anti-inflammatory drugs, and cocaine are discussed in detail. Specific aspects of common paediatric poisonings are reviewed.

Silent acetaminophen-induced hepatotoxicity in febrile children: does this entity exist?

Several descriptions of acetaminophen-associated liver injury caused by therapeutic or a dosage slightly above the recommended dosage have been described. Our hypothesis is that in sick febrile infants and children, who may also be calorie depleted, there might be an increased hepatic vulnerability to acetaminophen.

AIM

(1) To correlate serum acetaminophen levels in febrile infants and children with the following parameters: aspartate aminotransferase (AST) levels, fever, vomiting and/or decreased caloric intake; and (2) to assess parental knowledge regarding the medication dosage and hazards of acetaminophen.

METHODS

Healthy children with an acute febrile illness, who had received acetaminophen, were eligible to participate in the study. AST and acetaminophen levels were drawn, and a detailed questionnaire was completed for every child.

RESULTS

107 children participated in the study; 50 girls and 57 boys with ages ranging from 1 mo to 16 y (mean 33 mo). All serum acetaminophen levels were within the safety range. Although 32% of parents administered a single acetaminophen dose above 15 mg/kg and 46% gave a daily dose above 60 mg/kg/d, no significant differences were observed in the serum acetaminophen and AST levels compared to those who received the appropriate dose. In about 60% of cases, the high doses were recommended by a physician. Young age and high fever were associated with significantly higher acetaminophen levels. We could not find an association between acetaminophen levels and vomiting, decreased caloric intake and AST levels. Only 24 parents (22%) were aware of the possible toxicity of acetaminophen.

CONCLUSIONS

No evidence of increased hepatic vulnerability to acetaminophen was noted in a cohort of febrile infants and children. Furthermore, significant numbers of parents and physicians were unaware of acetaminophen dangers.

Acetaminophen intoxication and length of treatment: how long is long enough?

The currently recommended dosing scheme for treating acetaminophen overdose in the United States consists of a loading dose of oral N-acetylcysteine 140 mg/kg, followed by 70 mg/kg every 4 hours for 17 doses, for a total of 72 hours of oral N-acetylcysteine therapy. This protocol has been both effective and safe. We critically evaluated the evidence that supports reducing the course of N-acetylcysteine therapy from 72 hours to 24 or 36 hours. This shorter regimen offers important benefits for both the patient and the patient's family, such as increased drug tolerability and reduced hospital stay. Patients who intentionally ingested acetaminophen with harmful intent could receive appropriate psychosocial treatment more quickly. In addition, shorter courses of N-acetylcysteine therapy have positive financial ramifications by reducing the hospital stay by 1 or 2 days. Clearly, a shorter treatment regimen would not be appropriate for all patients, particularly those who seek treatment late (> 24 hrs after ingestion) and those with evidence of organ toxicity. In order to provide the necessary evidence to support a change in accepted clinical practice, further investigation on the safety and efficacy of a shorter N-acetylcysteine regimen should be conducted by clinical researchers in a controlled manner.

Acetaminophen hepatotoxicity

Unlike the bulk of medications, described in this fascicle, that cause liver injury in humans, acetaminophen is a non-prescription drug that can be purchased in drug stores and supermarkets without a physician's involvement. Death or severe injury is far more likely to occur with its use than with all the other medications considered in this study. Whereas attempts to control the quantity of drug ingested have been made in the United Kingdom and elsewhere in Europe, no comparable moves have taken place in the United States. The Food and Drug Administration claims to have concerns about the situation, however, but has yet to make an effort to more closely regulate the marketing and distribution of the drug. It is to be hoped that this will not be the case by the time the next issue of Drug Hepatotoxicity is scheduled for this series.

Do Poison Center Guidelines Adversely Affect Patient Outcomes as Triage Referral Values Increase?

BACKGROUND

The purpose of this study was to determine whether patient outcomes were adversely affected as healthcare referral values increased for two common poisonings: acute, unintentional acetaminophen (APAP) poisonings and acute, unintentional iron (Fe) poisonings. We hypothesized that symptom rates would increase with high referral values.

METHODS

Qualifying 1997 exposures were separated by substance (APAP or Fe) and then further stratified into three healthcare referral value ranges. Symptomatic and asymptomatic patients were totaled for each stratum. Expected vs. observed distributions of symptomatic and asymptomatic patients across triage referral strata for a given substance and treatment location were compared using chi-square test for independence. The Wilcoxon-Mann-Whitney test was used to compare the distribution of patients across referral strata for home vs. healthcare facility locations for a specific substance.

RESULTS

There were no statistically significant differences in the distribution of symptomatic patients within referral value strata for APAP or for Fe. There was also no difference in distribution of symptomatic patients across strata when comparing home vs. healthcare facility for APAP and Fe.

CONCLUSION

Referral values as high as 201 mg/kg for APAP and 61 mg/kg for Fe do not appear to adversely affect patient outcomes.

Antipyretic efficacy of an initial 30-mg/kg loading dose of acetaminophen versus a 15-mg/kg maintenance dose

OBJECTIVE

To compare the antipyretic efficacy of an initial 30-mg/kg acetaminophen loading dose versus a 15-mg/kg maintenance dose.

METHODS

A double-blind, parallel-group, randomized clinical trial was conducted. A total of 121 febrile (rectal temperature between 39 degrees C and 40 degrees C) but otherwise healthy outpatients who were 4 months to 9 years of age and weighed 4 to 26 kg were assigned randomly to 1 of the dose groups: 15 mg/kg (n = 62) and 30 mg/kg (n = 59).

RESULTS

In an "intention to treat" analysis, the time to obtain a temperature lower than 38.5 degrees C was significantly shorter in the 30-mg/kg than in the 15-mg/kg group (110 +/- 94 minutes vs 139 +/- 113 minutes). The maximum temperature decrease was significantly higher in the 30-mg/kg than in the 15-mg/kg group (2.3 +/- 0.7 degrees C vs 1.7 +/- 0.6 degrees C). Duration of rectal temperature below 38.5 degrees C was significantly longer in the 30-mg/kg than in the 15-mg/kg group (250 +/- 92 minutes vs 185 +/- 121 minutes, respectively). Adverse events were reported in 6 children in the 30-mg/kg group compared with 5 in the 15-mg/kg group (hyperthermia, hypothermia, vomiting). The difference was not statistically significant.

CONCLUSION

An initial 30-mg/kg acetaminophen loading dose seemed to be more effective in reducing fever than a 15-mg/kg maintenance dose. No difference was observed regarding clinical tolerance. These data suggest that acetaminophen treatment of fever may be more efficient in an initial loading dose.

Childhood poisoning in Queensland: an analysis of presentation and admission rates

OBJECTIVE

To determine the presentation rates for paediatric poisoning by ingestion and the determinants of hospital admission.

METHODOLOGY

Cross-sectional survey using an injury surveillance database from emergency departments in South Brisbane, Mackay and Mt Isa, Queensland, from January 1998 to December 1999. There were 1516 children aged 0-14 years who presented following ingestional poisoning.

RESULTS

The presentation rates for poisoning were 690, 40 and 67 per 100000 population aged 0-4, 5-9 and 10-14 years, respectively. The admission rates to hospital for poisoning were 144, 14 and 22 per 100000 population aged 0-4, 5-9 and 10-14 years, respectively. Although presentation rates for poisoning were higher in the rural centres the admission rates were disproportionately high for the 0-4 years age group. The agents most frequently ingested were paracetamol, Dimetapp, rodenticides and essential oils.

CONCLUSION

There is a need to design and implement interventions aimed at reducing poison exposures and unnecessary hospital admissions in the 0-4 years age group.

Rational use of toxicology testing in children

The majority of all patients with poison exposures in the United States are children. The evaluation and management of poisoned patients may be aided by the use of laboratory assays, ranging from basic assessments not uniquely indicated for the poisoned patient to highly sophisticated laboratory tests with very specific indications. Literature concerning poisoning in pregnant patients is evaluated and recommendations regarding the utility of pregnancy testing in poisoned females are discussed. Recent studies evaluating the use of toxicology testing in pediatrics have concluded that the use of comprehensive toxicology screening in pediatric patients is costly and does not affect the medical management of most poisoned patients. The utility of focused quantitative serum assays to determine serum levels of particular poisons is reviewed. Toxicology tests used for detection of drugs of abuse, with a particular focus on the capabilities and limitations of such tests, are discussed. The potential pitfalls that occur when toxicology tests are obtained indiscriminately, are misapplied, or are misunderstood are analyzed. Hair sampling as nonemergent toxicology testing for drugs of abuse is discussed.