Repeated supratherapeutic doses of paracetamol in children--a literature review and suggested clinical approach

Paracetamol overdose in the newborn and infant: a life-threatening event

PURPOSE

Paracetamol is the only drug recommended to treat fever in neonates. At recommended doses, paracetamol has not been associated with liver injury in neonates, while hepatotoxicity may occur after intake of a single high dose or multiple excessive doses. The aim of this narrative review is to critically analyze and summarize the available literature on newborns and infants exposed to supratherapeutic doses of paracetamol, with special focus on their clinical features, outcome, and management.

METHODS

The PubMed, SCOPUS, and Google Scholar search engines were used to collect data, without time limitation. The following keywords were used: paracetamol/acetaminophen, overdose, hepatotoxicity, N-acetylcysteine, newborn, infant.

RESULTS

The literature search identified a total of 27 case reports, a number of review articles, and few other relevant publications. Neonatal poisoning from paracetamol resulted from transplacental drug transfer after maternal overdose in some published cases, while it was the consequence of medication errors in other cases. Newborns and infants who have received a single overdose and have paracetamol concentrations below the Rumack-Matthew nomogram limits are at low risk of serious hepatic damage, while those who have recently ingested more than one supratherapeutic dose of paracetamol should be managed with caution. The treatment of choice for paracetamol poisoning is N-acetylcysteine, a specific antidote which reduces paracetamol hepatotoxic effects. N-Acetylcysteine should be given according to specific regimens through weight-based dosing tables.

CONCLUSIONS

Caution should be used when paracetamol is administered to the newborn. In the event of an overdose, careful patient monitoring and personalization of post-overdose procedures are recommended.

Evaluating lactate prognostic value in children suspected of acetaminophen-induced liver failure in Liberia

BACKGROUND

The prognostic significance of hyperlactatemia in young children with liver injury suspected to be attributed to repeated supratherapeutic doses of acetaminophen remain understudied.

METHODS

We conducted a retrospective medical chart review including children aged <5 years admitted with hepatocellular injury. The study was conducted in Bardnesville Junction Hospital operated by Médecins Sans Frontières in Monrovia, Liberia.

RESULTS

We analyzed 95 children with liver injury in whom a blood lactate measurement on admission was available. Eighty children (84%) were aged <2 years; 49 children (52%) died during hospitalization. The median acetaminophen concentration on admission was 20 mg/L with 60 (70%) children presenting concentrations exceeding 10 mg/L. Median lactate was significantly higher in children who died (10.7 mmol/L; interquartile range (IQR): 8.5-15.7) than those who survived (6.1 mmol/L; IQR: 4.1-8.5), P value < 0.001). The optimal threshold obtained was 7.2 mmol/L with a sensitivity of 84% and specificity 70% (area under curve = 0.80). The previously established thresholds of 3.5 and 4 mmol/L lactate had very low specificity identifying non-survival in children included in this study.

CONCLUSION

In this setting, young children with ALF possibly attributed to acetaminophen toxicity were unlikely to survive if the venous blood lactate concentration exceeded 7.2 mmol/L.

Parental Experience of Potential Adverse Drug Reactions Related to Their Oral Administration of Antipyretic Analgesic Medicines in Children in Saudi Arabia

BACKGROUND

Oral antipyretic analgesic medicines are commonly used in children and have the potential for adverse drug reactions (ADRs).

OBJECTIVE

The aim of this study was to explore parental experiences of potential ADRs related to their oral administration of antipyretic analgesics in children in the Kingdom of Saudi Arabia.

METHODS

For this cross-sectional survey, a paper-based questionnaire, consent form and information sheet were handed out to 1000 parents who had administered an oral antipyretic analgesic medicine to their children during the previous 3 months. Data were entered and analyzed using SPSS version 21.0 (IBM-SPSS Inc, Armonk, NY). Simple descriptive and inferential statistics were used. Management and ethical approvals were attained.

RESULTS

During March to April 2017, 661 parents agreed to participate, giving a response rate of 66.1%. Of the surveyed sample, 208 parents had observed 1 or more potential ADRs (31.5%, n = 208 out of 661). Parents' (n = 208) most commonly reported potential ADRs (n = 523) were loss of appetite (23%, n = 120 out of 523), stomachache (20.3%, n = 106 out of 523), abdominal colic (13%, n = 68 out of 523), and diarrhea (10.3%, n = 54 out of 523). Parents described severity of the ADRs as slight (71.8%, n = 342 out of 476), annoying to the child (7.9%, n = 85 to of 476), significant and affecting daily tasks (3.6%, n = 17 out of 476) and significant and led to the hospital (6.7%, n = 32 out of 476). Fever was the top-ranked reason for using antipyretic analgesic medicines (41.0%, n = 271 out of 661), followed by toothache (25.0%, n = 165 out of 661) and tonsillitis/laryngitis (24.7%, n = 163 out of 661). Among parents, 34.7% (n = 165 out of 476) did not seek medical attention when a potential ADR occurred, whereas 26.3% (n = 125 out of 476) of parents took their children to hospital clinics.

CONCLUSIONS

Although the majority of parentally reported (but not proven) ADRs were mild, a number of significant ADRs were reported. Future research should consider whether there is a role for physicians and pharmacists in educating parents in Saudi Arabia, and perhaps more widely, about the optimal use of oral antipyretic and analgesic medicines in children. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX)© 2020 Elsevier HS Journals, Inc.

Suspected paracetamol overdose in Monrovia, Liberia: a matched case-control study

Background

A cluster of cases of unexplained multi-organ failure was reported in children at Bardnesville Junction Hospital (BJH), Monrovia, Liberia. Prior to admission, children’s caregivers reported antibiotic, antimalarial, paracetamol, and traditional treatment consumption. Since we could not exclude a toxic aetiology, and paracetamol overdose in particular, we implemented prospective syndromic surveillance to better define the clinical characteristics of these children. To investigate risk factors, we performed a case–control study.

Methods

The investigation was conducted in BJH between July 2015 and January 2016. In-hospital syndromic surveillance identified children with at least two of the following symptoms: respiratory distress with normal pulse oximetry while breathing ambient air; altered consciousness; hypoglycaemia; jaundice; and hepatomegaly. After refining the case definition to better reflect potential risk factors for hepatic dysfunction, we selected cases identified from syndromic surveillance for a matched case–control study. Cases were matched with in-hospital and community-based controls by age, sex, month of illness/admission, severity (in-hospital), and proximity of residence (community).

Results

Between July and December 2015, 77 case-patients were captured by syndromic surveillance; 68 (88%) were under three years old and 35 (46%) died during hospitalisation. Of these 77, 30 children met our case definition and were matched with 53 hospital and 48 community controls. Paracetamol was the most frequently reported medication taken by the cases and both control groups. The odds of caregivers reporting supra-therapeutic paracetamol consumption prior to admission was higher in cases compared to controls (OR 6.6, 95% CI 2.1–21.3). Plasma paracetamol concentration on day of admission was available for 19 cases and exceeded 10 μg/mL in 10/13 samples collected on day one of admission, and 4/9 (44%) collected on day two.

Conclusions

In a context with limited diagnostic capacity, this study highlights the possibility of supratherapeutic doses of paracetamol as a factor in multi-organ failure in a cohort of children admitted to BJH. In this setting, a careful history of pre-admission paracetamol consumption may alert clinicians to the possibility of overdose, even when confirmatory laboratory analysis is unavailable. Further studies may help define additional toxicological characteristics in such contexts to improve diagnoses.

Fatal acetaminophen poisoning with hepatic microvesicular steatosis in a child after repeated administration of therapeutic doses

Acetaminophen is the leading cause of acute liver failure worldwide following massive ingestion. We present here a fatal acute liver failure after repeated administration of four therapeutic doses of acetaminophen at 4-h intervals in a previously healthy 9-year-old female who presented dental pain after a facial trauma during sport practice. A diagnosis of paracetamol-induced hepatitis was deduced from the clinical picture of fulminant hepatitis and tubular necrosis, the encephalopathy with oedema and without signs of trauma. Liver biopsy showed typical acetaminophen-induced necrosis and a microvesicular steatosis in periportal hepatocytes. These injuries might have been favored by pre-existing mitochondrial dysfunction related, for instance, to a deficiency in an enzyme of the mitochondrial β-oxidation pathway, or the respiratory chain. The observation of microvesicular steatosis in the periportal areas suggests an increased vulnerability via pre-existing mitochondrial dysfunction. As the liver status of patients is mostly unknown, the frequency of administration (every six hours) must be respected and the use of pharmaceutical forms allowing to adjust the dose as closely as possible to the child's weight should be promoted.

Population Pharmacokinetic Modeling of Acetaminophen Protein Adducts in Adults and Children

Acetaminophen protein adducts (adducts) are a well-established biomarker to diagnose acetaminophen toxicity. To date, the quantitative relationship between acetaminophen exposure, which drives adduct formation, and adduct exposure remains to be established. Our study characterized the adduct formation and disposition in adults using the approach of population parent-metabolite modeling. It demonstrated formation-limited pharmacokinetics (PK) for adducts in healthy subjects. This finding expands the existing knowledge on adduct PK that showed an apparent long elimination half-life. We then allometrically scaled the adduct PK model to children, simulated the adduct profiles, and compared these simulated profiles with those observed in an independent cohort of children. The scaled model significantly overpredicted the adduct concentrations in children early on in treatment and underpredicted concentrations following repeated acetaminophen doses. These results suggest that children demonstrate different adduct PK behavior from that of adults, most likely because of increased reactive metabolite detoxification in children. In summary, we described the first PK model linking acetaminophen and acetaminophen protein adduct concentrations, which provides a semimechanistic understanding of varying profiles of adduct exposure in adults and children.

Acetaminophen Protein Adducts in Hospitalized Children Receiving Multiple Doses of Acetaminophen

Previous reports have questioned the safety of multiple doses of acetaminophen administered to ill children. Acetaminophen protein adducts (adducts) are a biomarker of acetaminophen‐induced liver injury and reflect the oxidative metabolism of acetaminophen, a known mechanism in acetaminophen toxicity. In this prospective observational study, we analyzed adduct concentrations in 1034 blood samples obtained from 181 hospitalized children (1 to 18 years inclusive) who received 2 or more doses of acetaminophen. Linear regression analysis showed that serum adduct concentrations increased as a function of the cumulative acetaminophen dose, which could be attributed, in part, to a long half‐life of adducts (2.17 ± 1.04 days [mean ± standard deviation]) in children. However, few patients (2%) were found to have adduct concentrations higher than 1.0 nmol/mL, a previously identified toxicity cut point for the diagnosis of acetaminophen‐induced liver injury in patients with alanine aminotransferase values exceeding 1000 IU/L. A small cohort of patients with suspected infection was noted to show higher adduct concentrations. In addition, adduct concentrations showed a stronger correlation with cumulative acetaminophen doses in adolescents compared with children (R² = 0.41 vs 0.26). No other covariates (body weight, body mass index z score, sex, race, or surgery) remarkably correlated with adduct elevation. In summary, low levels of adducts can be detected in hospitalized children receiving multiple doses of acetaminophen, and adduct levels correlate with cumulative acetaminophen dose.

Fifteen-minute consultation: Pain relief for children made simple-a pragmatic approach to prescribing oral analgesia in the postcodeine era

What are the most effective doses of simple oral analgesics such as paracetamol and ibuprofen for pain relief in children? Why can't I prescribe codeine phosphate for children anymore? Is oral morphine really a safe alternative to codeine phosphate, and if so what dose should I prescribe? These questions are frequently asked by clinicians who wish to give analgesics to children for pain relief. In this article I will address these questions and describe a pragmatic approach for pain relief using oral analgesics based on the best evidence available and my experience as a consultant paediatric anaesthetist.

Hepatotoxicity induced by acute and chronic paracetamol overdose in children: Where do we stand?

BACKGROUND

There are few data on hepatotoxicity induced by acute or chronic paracetamol poisoning in the pediatric population. Paracetamol poisoning data can reveal the weaknesses of paracetamol poisoning management guidelines.

METHODS

We retrospectively studied the patients of less than 18 years old with measurable paracetamol levels, who were brought to the emergency department (ED) of La Paz University Hospital, Madrid, Spain, for suspected paracetamol overdoses between 2005 and 2010.

RESULTS

Ninety-two patients with suspected paracetamol poisoning were identified. In 2007, the incidence of paracetamol poisoning in the pediatric population was 0.8 [Poisson-95% confidence interval (CI): 0.03-3.69] per 10 000 inhabitants aged less than 18 years. The incidence in the same year was 1.53 (Poisson-95% CI: 0.24-5.57) per 10 000 patients in the pediatric ED. The most common cause of poisoning was attempted suicide (47.8%) in teenagers with a median age of 15 years, followed by accidental poisoning (42.2%) in babies with a median age of 2.65 years. Difference was seen in the frequency of hepatotoxicity between acute and chronic poisoning cases. Only 1 of 49 patients with acute poisoning showed hepatotoxicity [acute liver failure (ALF)], whereas 7 of 8 patients with chronic poisoning showed hepatotoxicity (3 cases of ALF). The average time to medical care was 6.83 hours for acute poisoning and 52.3 hours for chronic poisoning (P<0.001).

CONCLUSIONS

Chronic paracetamol poisoning is a potential risk factor for hepatotoxicity and acute liver failure. Delays in seeking medical help might be a contributing factor. Clinicians should have a higher index of clinical suspicion for this entity.

Determinants of hepatotoxicity after repeated supratherapeutic paracetamol ingestion: systematic review of reported cases

AIMS

To evaluate the role of reported daily dose, age and other risk factors, and to assess the value of quantifying serum transaminase activity and paracetamol (acetaminophen) concentration at initial assessment for identifying patients at risk of hepatotoxicity following repeated supratherapeutic paracetamol ingestion (RSPI).

METHODS

Systematic literature review with collation and analysis of individual-level data from reported cases of RSPI associated with liver damage.

RESULTS

In 199 cases meeting the selection criteria, severe liver damage (ALT/AST ≥1000 IU l(-1) , liver failure or death) was reported in 186 (93%) cases including 77/78 (99%) children aged ≤6 years. Liver failure occurred in 127 (64%) cases; of these 49 (39%) died. Maximum ingested daily paracetamol doses were above UK recommendations in 143 (72%) patients. US-Australasian thresholds for repeated supratherapeutic ingestions requiring intervention were not met in 71 (36%) cases; of these 35 (49%) developed liver failure and 10 (14%) died. No cases developing liver damage had paracetamol concentration < 20 mg l(-1) and a normal ALT/AST on initial presentation or when RSPI was first suspected, but both of these values were only available for 79 (40%) cases.

CONCLUSIONS

Severe liver damage is reported after RSPI in adults and children, sometimes involving reported doses below current thresholds for intervention. Paracetamol concentrations <20 mg l(-1) with normal serum ALT/AST activity on initial assessment suggests a low risk of subsequent liver damage. These findings are, however, limited by low patient numbers, publication bias and the accuracy of the histories in reported cases.

Acetaminophen administration in pediatric age: an observational prospective cross-sectional study

Background

Parents often do not consider fever as an important physiological response and mechanism of defense against infections that leads to inappropriate use of antipyretics and potentially dangerous side effects. This study is designed to evaluate the appropriateness of antipyretics dosages generally administered to children with fever, and to identify factors that may influence dosage accuracy.

Results

In this cross-sectional study we analyzed the clinical records of 1397 children aged >1 month and < 16 years, requiring a primary care (ambulatory) outpatient visit due to fever. We evaluated the number of children who had received >90 mg/kg/day of acetaminophen, the prescriber, the medication formula and the educational level of the caregiver who administered acetaminophen. Among those children included in our study, 74 % were administered acetaminophen for body temperature ≤ 38.4 °C. 24.12 % of children received >90 mg/kg/day of acetaminophen. Parents with university qualifications most commonly self-administered acetaminophen to their children, in a higher than standard dose. Self medication was also described in 60 % of children, whose acetaminophen was administered for temperatures < 38 °C. Acetaminophen over-dosage was also favored by the use of drug formulations as drops or syrup.

Conclusions

Our study shows that preventive action should be taken regarding the use of acetaminophen as antipyretic drug in children in order to reduce the fever phobia and self-prescription, especially of caregivers with higher educational levels. It is also necessary to promote a more appropriate use of acetaminophen in those parents using drops or syrup formulations.

Acute Liver Failure and Hepatic Encephalopathy After Cleft Palate Repair

Paracetamol is the most commonly used analgesic after cleft palate repair. It has rarely caused acute hepatic failure at therapeutic or supratherapeutic doses. Only one case of therapeutic paracetamol toxicity after cleft palate repair had been reported previously. Here, we present a similar patient who developed acute liver failure and hepatic encephalopathy after an uncomplicated cleft palate surgery. Lack of large prospective trials in young children due to ethical concerns increases the value of the case reports of acetaminophen toxicity at therapeutic doses. The dosing recommendations of paracetamol may need to be reconsidered after cleft palate surgery.

Off-label use of medicines in paediatric inpatients at an Australian teaching hospital

AIM

The study aims to investigate the prevalence of off-label prescribing in the general paediatric ward at a major teaching hospital in Tasmania, Australia.

METHOD

The drug charts and medical records from two groups of 150 consecutive paediatric patients, admitted 6 months apart in July 2009 and January 2010, were studied retrospectively. Patients were required to spend at least one night in hospital and be aged less than 12 years. Each prescribed drug was compared with the approved product information to determine if the usage was off-label. Data concerning documented informed consent and adverse drug reactions were also recorded.

RESULTS

Three hundred patients were prescribed a total of 887 medicines. Of these, 31.8% were off-label and 57.3% of children received an off-label medication. There was no significant seasonal variation in patient characteristics or prescriptions. Drugs were most commonly off-label due to their dosage or frequency of administration. Of the 106 different drugs used, the use of 51 was off-label on at least one occasion, and for 30 drugs their use was off-label on more than 75% of occasions. The drugs most commonly used off-label were oxycodone, salbutamol and paracetamol. No informed consent documentation was identified, and two of five recorded adverse drug reactions were associated with off-label drug use.

CONCLUSION

Off-label use of medicines occurred frequently in paediatric inpatients. The available evidence often supported off-label medication use. An improved system for the revision of approved drug information and an Australian guideline for paediatric prescribing are needed.

Overdosed prescription of paracetamol (acetaminophen) in a teaching hospital

INTRODUCTION

Paracetamol is the most commonly used analgesic and antipyretic. Reviews of hospital use of paracetamol are scarce. Little is known about the appropriateness of the dose of paracetamol prescribed for hospitalized adults. The aim of this study was to report on the nature and the frequency of the overdosed prescription of paracetamol observed in adult patients over a 4.5-year period in a teaching hospital.

METHODS

Prescription analysis by pharmacists was performed once a week in six medical and three surgical departments and daily in a post-emergency unit. In cases of prescription error, the pharmacist notified the physician through an electronic alert when a computerized prescription order entry system was available or otherwise by face-to-face discussion. For each drug-related problem detected, the pharmacists recorded relevant details in a database.

RESULTS

From October 2006 to April 2011, 44,404 prescriptions were reviewed and 480 alerts related to the overdosed prescription of paracetamol were made (1% of analyzed prescriptions). The extent of errors of dosage was within the intervals [90-120 mg/kg/d] and greater than 120 mg/kg/d for 87 and 11 patients respectively, who were prescribed a single non-combination paracetamol containing product. Sixty alerts concerned co-prescription of at least two paracetamol containing products with similar frequency for computerized (1.4/1000) or handwritten (1.2/1000) prescriptions.

DISCUSSION

Prescriptions of paracetamol for hospitalized adults frequently exceed the recommended dosage.

CONCLUSION

These results highlight the need for increased awareness of unintentional paracetamol overdose and support the initiation of an educational program aimed at physicians and nurses.

Acute haemolytic crisis due to concomitant presence of infection and possible altered acetaminophen catabolism in a Philipino child carrying the G6PD-Vanua Lava mutation

Glucose-6-phosphate dehydrogenase (G6PD), an X-linked hereditary deficiency, is the most common of all clinically significant enzyme defects. While many drugs are responsible for haemolytic anaemia in G6PD-deficient patients, acetaminophen's imputability is still under debate, although an overdose of this drug can provoke acute haemolytic events. We report a case of a Philipino child carrying the G6PD-Vanua Lava mutation with acute haemolytic crisis related to infection in progress and acetaminophen's administration. Fever and concomitant infection, through an increment of erythrocyte glutathione depletion, sensitized the infant to the haemolytic event. In this condition, acetaminophen (or paracetamol [PCM]) was capable of inducing a haemolytic crisis in our G6PD-deficient patient although administered under standard conditions. PCM seems to have induced the haemolytic event, probably by the alteration of its catabolism due to dehydration and fever. The enzymatic G6PD instability associated to the presence of the G6PD-Vanua Lava mutation could have led to an increment of red blood cells' sensitivity to lysis; hence, it is possible that PCM toxicity may also be due to the presence of this particular mutation. Finally, we propose a new biochemical classification of this G6PD variant.

Fulminant hepatitis after 10 days of acetaminophen treatment at recommended dosage in an infant

Acetaminophen is considered a safe drug for children, although hepatotoxicity may develop after overdosing. Reports of liver failure after repeated therapeutic doses of the drug have been rare. Here we describe the case of an infant who developed acute liver failure after administration of acetaminophen for 10 days at a total dose of 720 mg/day (72 mg/kg per day). The patient had high levels of aspartate aminotransferase (11 735 U/L) and alanine aminotransferase (6611 U/L) accompanied by encephalopathy and an increased ammonium level (266 μg/dL). Intravenous N-acetylcysteine therapy resulted in rapid improvement of the child's clinical condition and laboratory test results. Health care providers should be aware that multiple doses of acetaminophen in infants may lead to acute hepatic failure. N-acetylcysteine therapy should be initiated in cases of drug-induced acute liver failure.

A Population Study of the Frequency of High-Dose Acetaminophen Prescribing and Dispensing

Background:

Recurrent intake of 4 g/day or more of acetaminophen has been associated with elevation of serum alanine aminotransferase (ALT) levels in 30–40% of the exposed population and may result in hepatotoxicity.

Objective:

To describe the frequency that patients are prescribed acetaminophen doses that exceed 4 g/day across a large population.

Methods:

Using California's Medicaid (MediCal) fee-for-service population, pharmacy claims including over-the-counter (OTC) medications were examined for prescriptions that could result in acetaminophen doses of 4 g/day or more. The period studied, October 2004 through September 2005, was before the Part D pharmacy benefit was available to dually eligible Medicare patients when all prescriptions were covered by the MediCal claims process.

Results:

During the pre-Part D evaluation period, approximately 3.27 million beneficiaries were enrolled in the fee-for-service MediCal program. A total of 192,716 (5.9%) were potentially exposed to at least 1 day of 4 g/day or more of acetaminophen. Of those, 769 patients were potentially exposed to at least 1 day of 16 g/day or more. A total of 2664 beneficiaries were dispensed prescriptions and OTC products that, if taken as directed, would have resulted in more than 100 days of acetaminophen doses of 4 g/day or more during the study year.

Conclusions:

Despite electronic systems designed to warn dispensing pharmacists of duplications of drug class and cumulative excessive doses, potentially toxic amounts of acetaminophen are commonly prescribed and dispensed to this population. Better systems, increased awareness, and education of patients, prescribers, and pharmacists are needed to reduce this potential toxic exposure.

Acute hepatic failure in an infant caused by acetaminophen (paracetamol) toxicity

A 7-month-old infant developed acute fatal hepatic failure owing to inadvertent duplication of paracetamol prescriptions. Paracetamol toxicity should be considered in the differential diagnosis of infants presenting with acute hepatic failure.

Acute hepatic injury in four children with Dravet syndrome: Valproic acid, topiramate or acetaminophen?

We describe four children with Dravet syndrome treated with the combination of valproic acid (VPA) and topiramate (TPM) who developed transient liver toxicity. The time-interval between fever, administration of acetaminophen, epileptic status and liver enzyme disturbances in our four cases suggests that accumulation of toxic acetaminophen-metabolites is possibly responsible for liver toxicity. If acetaminophen and its metabolites cause those liver problems in children treated with the combination of VPA and TPM, the advice to use acetaminophen for treating fever in children using this combination, should be changed. Only future clinical observations and research can solve this clinical dilemma.