Paracetamol use in pregnancy and wheezing in early childhood

Associations between cord blood acetaminophen biomarkers and childhood asthma with and without allergic comorbidities

BACKGROUND

Previous studies have linked prenatal acetaminophen use to increased asthma risk in children. However, none have explored this association while differentiating between asthma cases with and without other allergic conditions or by employing objective biomarkers to assess acetaminophen exposure.

OBJECTIVE

To evaluate whether the detection of acetaminophen biomarkers in cord blood is associated with the subgroups of asthma both with and without allergic comorbidities in children.

METHODS

Acetaminophen biomarkers, including unchanged acetaminophen and acetaminophen glucuronide, were measured in neonatal cord blood samples from the Boston Birth Cohort. Asthma subgroups were defined on the basis of physician diagnoses of asthma and other allergic conditions (atopic dermatitis and allergic rhinitis). Multinomial regressions were used to evaluate the associations between acetaminophen biomarkers and asthma subgroups, adjusting for multiple confounders, including potential indications for maternal acetaminophen use such as maternal fever.

RESULTS

The study included 142 children with asthma and at least 1 other allergic condition, 55 children with asthma but no other allergic condition, and 613 children free of asthma. Detection of acetaminophen in cord blood, reflecting maternal exposure to acetaminophen shortly before delivery, was associated with 3.73 times the odds of developing asthma without allergic comorbidities (95% CI: 1.79-7.80, P = .0004). In contrast, the detection of acetaminophen in cord blood was not associated with an elevated risk of asthma with allergic comorbidities. Analysis of acetaminophen glucuronide yielded consistent results.

CONCLUSION

In a prospective birth cohort, cord blood acetaminophen biomarkers were associated with an increased risk of childhood asthma without allergic comorbidities, but were not associated with childhood asthma with allergic comorbidities.

Maternal prenatal paracetamol ingestion and scholastic attainments of the offspring

Background: Fetal exposure to paracetamol (acetaminophen) has been shown to be associated with asthma and other atopic disorders, as well as behavioural problems including hyperactivity, in childhood. However, there is little information on scholastic abilities among children exposed to paracetamol in pregnancy. Objectives: To determine whether there are any differences in scholastic abilities among the offspring of women who ingested paracetamol during pregnancy compared with non-exposed children. Methods: Mothers enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) had recorded the frequency with which they had taken the medication over two time periods during pregnancy: i) the first 18 weeks and ii) 18-32 weeks. The offspring have been followed up ever since. For this study we use as outcomes: a) 14 tests of ability at reading and 2 of spelling using the study's tests and the national education system test results; b) 6 of mathematical abilities including tests of arithmetic and mathematical reasoning, and c) 1 of scientific understanding. Multiple regression was used, adjusting for 15 different exposures including reasons for taking the medication as well as demographic features. Results: Almost all unadjusted and adjusted mean differences were negative (i.e., those exposed to maternal intake of paracetamol did less well), but negative associations for exposures between 18 and 32 weeks of gestation were much more evident than for exposures earlier in pregnancy. Of the later exposures, after adjustment, 12 of the 23 scholastic tests were associated with prenatal exposure to paracetamol at p < 0.05. These negative effects were found in the girls (12 tests at p < 0.05) but not boys (0 tests at p < 0.05). Conclusion: Evidence from this longitudinal study suggests that maternal exposure to paracetamol is associated with disadvantages to the offspring in scholastic abilities such as mathematics and reading at secondary school ages. This raises the question as to whether there are longer-lasting effects on educational attainment from age 15 years onwards, including at university level. Clearly these results should be tested in other settings, but meanwhile they add to a growing accumulation of known adverse effects of exposure to paracetamol in pregnancy.

Acetaminophen for the patent ductus arteriosus: has safety been adequately demonstrated?

Patent ductus arteriosus (PDA) is the most common cardiovascular condition diagnosed in premature infants. Acetaminophen was first proposed as a potential treatment for PDA in 2011. Since that time acetaminophen use among extremely preterm neonates has increased substantially. The limited available data demonstrate that acetaminophen reduces PDA without evident hepatotoxicity. These findings have led some to suggest that acetaminophen is a safe and effective therapy for PDA closure. However, the lack of apparent hepatoxicity is predictable. Acetaminophen induced cellular injury is due to CYP2E1 derived metabolites; and hepatocyte CYP2E1 expression is low in the fetal and neonatal period. Here, we review preclinical and clinical data that support the hypothesis that the lung, which expresses high levels of CYP2E1 during fetal and early postnatal development, may be particularly susceptible to acetaminophen induced toxicity. Despite these emerging data, the true potential pulmonary risks and benefits of acetaminophen for PDA closure are largely unknown. The available clinical studies in are marked by significant weakness including low sample sizes and minimal evaluation of extremely preterm infants who are typically at highest risk of pulmonary morbidity. We propose that studies interrogating mechanisms linking developmentally regulated, cell-specific CYP2E1 expression and acetaminophen-induced toxicity as well as robust assessment of pulmonary outcomes in large trials that evaluate the safety and efficacy of acetaminophen in extremely preterm infants are needed.

Safety of drugs used for the treatment of migraine during pregnancy: a narrative review

INTRODUCTION

Migraine is common in females of childbearing age and negatively impacts quality of life. The majority of those with migraine who become pregnant see an improvement in their condition but not all do. Providing evidence-based recommendations for the pharmacological management of migraine in pregnancy is challenging.

AREAS COVERED

This narrative review provides an update on the safety of drugs used for migraine in pregnancy. National and international guidelines on the management of episodic migraine in adults were used to select the drugs of relevance to pregnant women. The final list of drugs was chosen by a pain specialist who categorized them according to drug class and use in acute management or prevention. PubMed was searched from inception to 31st July 2022 for evidence on drug safety.

EXPERT OPINION

Obtaining high-quality drug safety data in pregnant migraineurs is difficult not least because exposing a fetus to research-related risks is often considered unethical. There is reliance on observational studies which often group drugs together and lack specificities pertinent to drug prescribing like timing, dosing and duration. Improved statistical tools, study designs and the creation of international collaborative frameworks are ways to advance knowledge on drug safety in pregnancy.

Effects of Prenatal Paracetamol Exposure on the Development of Asthma and Wheezing in Childhood: A Systematic Review and Meta-Analysis

The aim of the report was to evaluate whether in utero exposure to paracetamol is associated with risk towards developing respiratory disorders such as asthma and wheeze after birth. MEDLINE (PubMed), EMBASE and Cochrane Library databases were searched for articles published in English to December 2021. The study involved 330,550 women. We then calculated the summary risk estimates and 95% CIs and plotted forest plots using random effect models (DerSimonian-Laird method) and fixed effect models. We also performed a systematic review of the chosen articles and a meta-analysis of studies based on the guidelines outlined in the PRISMA statement. Accordingly, maternal exposure to paracetamol during pregnancy was associated with a significant increased risk of asthma: crude OR = 1.34, 95% CI: 1.22 to 1.48, p < 0.001; and significant increased risk of wheeze: crude OR = 1.31, 95% CI: 1.12 to 1.54, p < 0.002. Results of our study confirmed that maternal paracetamol use in pregnancy is associated with an enhanced risk of asthma and wheezing in their children. We believe paracetamol should be used with caution by pregnant women, and at the lowest effective dose, and for the shortest duration. Long-term use or the use of high doses should be limited to the indications recommended by a physician and with the mother-to-be under constant supervision.

Prevalence, Management, and Risk Factors of Asthma Among School-Age Children in Yogyakarta, Indonesia

Purpose

Childhood asthma in developing countries has been increasing, but underdiagnosed and undertreated. We reported prevalence, management, and risk factors of asthma among school-age children in Yogyakarta, Indonesia.

Patients and Methods

We recruited children aged 6-7 years and 13-14 years attending schools in all districts in Yogyakarta, Indonesia. The schools were randomly selected via cluster random sampling. We used the Indonesian version of the Global Asthma Network (GAN) questionnaire, and the methodology employed by this study was in accordance with the GAN's protocol.

Results

A total of 2106 children aged 6-7 years and 3142 adolescents aged 13-14 years were eligible for analysis. The prevalence of current wheeze in children and adolescents was similar, which was 4.6%. Inhalation therapy was reported in <30% of those with asthma. Risk factors for current wheeze in children were wheezing in infancy period, ever had pneumonia, the house was passed by trucks every day, and fast-food consumption in the previous 12 months; whereas exclusive breastfeeding for more than 6 months decreased the risk of current wheeze. In adolescence, obesity, consumption of fast food once or twice a week, and paracetamol in the previous 12 months increased the risk of current wheeze.

Conclusion

The prevalence of current wheeze in children and adolescents in Indonesia was quite low. The use of inhalation therapy was limited. Respiratory problems during infancy, environmental, and nutritional factors play a role in the development of asthma.

Potentially harmful medication use and the associated factors among pregnant women visiting antenatal care clinics in Mbarara Regional Referral Hospital, Southwestern Uganda

Background

Pregnancy management using medications has been challenging for both healthcare providers and pregnant women, given the fear of teratogenicity effects and the potential for fetal harm. In the developing world, poor health-seeking behavior of patients, delayed initiation of antenatal care (ANC), and low level of educational status of mothers could contribute to the issue of drug safety in pregnancy.

Aim

The aim of the study was to determine the prevalence and factors associated with potentially harmful medication use in pregnancy.

Methods

A cross-sectional study was conducted from April 1 to June 6, 2021, including 209 pregnant women on ANC follow-up at a referral hospital in Southwestern Uganda. The simple random sampling technique was employed to select study participants. Interviewer-administered questionnaires were used to collect the history of medication use since conception and then the participant's ANC card was reviewed to determine prescribed drug regimens and their indications. Statistical Package for the Social Sciences version 23.0 was used for analysis.

Results

Out of the 1,422 medications used by 209 women, 665 (42.2%) were category C, and 182 (11.5%) were category A. A total of 92 (44.0%) pregnant women used at least one potentially harmful medication during the current pregnancy. Having more than average monthly income (adjusted odds ratio [aOR] = 2.32 [1.04, 5.14 at 95% confidence interval (CI)]), having a chronic disease (aOR = 3.24 [1.17, 8.97 at 95% C.I]), using 7 and more medications (aOR = 9.12 [4.11, 20.24 at 95% CI]), and use of herbal medicines (aOR = 4.50 [2.10, 9.87 at 95% CI]) were shown to be risk factors.

Conclusion

The proportion of pregnant women that used at least one potentially harmful medication is higher than in previous studies. Having comorbidities and taking more medications increase the risk of receiving a potentially harmful medication during pregnancy.

Relevance to Patients

This study identified the gaps in the use of medicines during pregnancy which will enable the development and implementation of protocols for optimizing prescribing practices in pregnant women by focusing on the safety of the fetus.

Long-Term Safety of Prenatal and Neonatal Exposure to Paracetamol: A Systematic Review

Introduction: Paracetamol is the most commonly used antipyretic and analgesic in pregnancy. It is also increasingly used off-label in the neonatal intensive care unit. Despite the frequent use of paracetamol, concerns have been raised regarding the high variability in neonatal dosing regimens and the long-term safety of early life exposure. Objective: To investigate the available evidence on the long-term safety of prenatal and neonatal paracetamol exposure. Methods: We conducted a systematic search of the electronic databases Ovid Medline, Ovid Embase and Web of Science from inception to August 2021 for original research studies of any design that described the use of paracetamol in the prenatal or neonatal (within the first four weeks of life) periods and examined the occurrence of neurodevelopmental, atopic or reproductive adverse outcomes at or beyond birth. Results: We identified 1313 unique articles and included 30 studies in the final review. Of all studies, 27 (90%), two (7%) and one (3%) were on the long-term safety of prenatal, neonatal and both prenatal and neonatal exposure, respectively. Thirteen (46%), 11 (39%) and four (15%) studies examined neurodevelopmental, atopic and reproductive outcomes. Eleven (100%), 11 (100%), and three (27%) studies on prenatal exposure reported adverse neurodevelopmental, atopic and reproductive outcomes. Only one study found a possible correlation between neonatal paracetamol exposure and long-term adverse outcomes. Conclusions: The available evidence, although limited, suggests a possible association between prenatal paracetamol exposure and an increased risk of neurodevelopmental, atopic and reproductive adverse outcomes. There is an immediate need for robust data on the long-term safety of paracetamol exposure in the prenatal and neonatal periods.

Paracetamol exposure and asthma: What does the evidence say? An overview of systematic reviews

OBJECTIVE

To conduct an umbrella review collating the existing evidence to determine whether there is an association between exposure of Paracetamol in-utero or in infancy and the development of childhood Asthma.

METHODS

In this review, systematic reviews with or without meta-analysis that reported the association between paracetamol and asthma in children were included. To identify relevant reviews, a search was performed in the electronic databases PubMed, the Cochrane Library, and Ovid MEDLINE. The protocol was registered in PROSPERO CRD42020156023. A separate search was conducted for primary studies from the last 5 years not yet included in systematic reviews reporting the association from January 2016 to March 2021.

RESULTS

The electronic searches identified 1966 review titles. After the removal of 493 duplicates, 1475 titles and abstracts were screened against the eligibility criteria. Full-text screening yielded six systematic reviews to be included in this review. The search for primary studies in the last 5 years yielded 1214 hits, out of which 5 studies were found suitable for inclusion. Three of them, that were not included in the systematic reviews, and have been summarised in this paper. The odds ratios (ORs) for the outcome of asthma in offspring of mothers with prenatal paracetamol consumption in any trimester were 1.28 (1.13-1.39) and 1.21 (1.02-1.44). For first trimester exposures, they were 1.12 (0.99-1.27), 1.39 (1.01-1.91), and 1.21 (1.14-1.28), for the second or third trimester, they were 1.49 (1.37-1.63) and 1.13 (1.04-1.23). For the third trimester only, the figure was 1.17 (1.04-1.31). Of the six reviews included, 1 had a low risk of bias, 2 had an unclear risk while 3 had a high risk of bias assessed using the ROBIS tool. There was no significant increased risk of asthma with early infancy exposure. The inter-study heterogeneity varied from I²  = 41% to I²  = 76% across reviews. In the primary studies, the OR for prenatal exposure ranged from 1.12 (0.25-4.98) to 4.66 (1.92-11.3) and for infancy exposure was 1.56 (1.06-2.30). All three included primary studies were adjudged to be of high quality using the Newcastle Ottawa scale.

CONCLUSIONS

There is a modest association between paracetamol exposure in-utero and the future development of asthma. Exposure in infancy has a less consistant association. All the studies done thus far are observational in nature, with their inherent biases. Further research, preferably randomized controlled trials are recommended to answer this pertinent question.

EA3: A softmax algorithm for evidence appraisal aggregation

Real World Evidence (RWE) and its uses are playing a growing role in medical research and inference. Prominently, the 21st Century Cures Act—approved in 2016 by the US Congress—permits the introduction of RWE for the purpose of risk-benefit assessments of medical interventions. However, appraising the quality of RWE and determining its inferential strength are, more often than not, thorny problems, because evidence production methodologies may suffer from multiple imperfections. The problem arises to aggregate multiple appraised imperfections and perform inference with RWE. In this article, we thus develop an evidence appraisal aggregation algorithm called EA³. Our algorithm employs the softmax function—a generalisation of the logistic function to multiple dimensions—which is popular in several fields: statistics, mathematical physics and artificial intelligence. We prove that EA³ has a number of desirable properties for appraising RWE and we show how the aggregated evidence appraisals computed by EA³ can support causal inferences based on RWE within a Bayesian decision making framework. We also discuss features and limitations of our approach and how to overcome some shortcomings. We conclude with a look ahead at the use of RWE.

Acetaminophen Attenuates invasion and alters the expression of extracellular matrix enzymes and vascular factors in human first trimester trophoblast cells

Acetaminophen is one of the most common medications taken during pregnancy, considered safe for maternal health and fetal development. However, recent epidemiological studies have associated prenatal acetaminophen use with several developmental disorders in offspring. As acetaminophen can freely cross into and through the placenta, epidemiological associations with prenatal acetaminophen use may reflect direct actions on the fetus and/or the impact of altered placental functions. In the absence of rigorous mechanistic studies, our understanding of how prenatal acetaminophen exposure can cause long-term effects in offspring is limited. The objective of this study was to determine whether acetaminophen can alter key functions of a major placental cell type by utilizing immortalized human first trimester trophoblast cells. This study employed a comparative analysis with the nonsteroidal, anti-inflammatory drug aspirin, which has established effects in first trimester trophoblast cells. We report that immortalized trophoblast cells express the target proteins of acetaminophen and aspirin: cyclooxygenase (COX) -1 and -2. Unlike aspirin, acetaminophen significantly repressed the expression of angiogenesis and vascular remodeling genes in HTR-8/SVneo cells. Moreover, acetaminophen impaired trophoblast invasion by over 80%, while aspirin had no effect on invasion. Acetaminophen exposure reduced the expression of matrix metalloproteinase (MMP)-2 and -9 and increased the expression of tissue inhibitors of matrix metalloproteinases 2, leading to an imbalance in the ratio of proteolytic enzymes. Finally, a bioinformatic approach identified novel acetaminophen-responsive gene networks associated with key trophoblast functions and disease. Together these results suggest that prenatal acetaminophen use may interfere with critical trophoblast functions early in gestation, which may subsequently impact fetal development.

Pharmacotherapy during Pregnancy: An Endodontic Perspective

Odontogenic pain affects up to 54.9% of pregnant women^1-3. This pain is often associated with pulpal and/or periapical infections that pose risks to women and their fetus. The American Dental Association in collaboration with the American College of Obstetricians and Gynecologists developed a consensus statement to affirm the importance of timely and appropriate oral health care as a critical component of a healthy pregnancy⁴. However, limited knowledge of endodontic procedure safety and related medication use often result in the avoidance of treatment during pregnancy. This article, a collaborative effort by specialists from endodontics, pediatric dentistry, and obstetrics, reviews the current evidence on the safety of medications commonly used in endodontics including local anesthetics, analgesics, anxiolytics, and antibiotics.

Development and validation of a questionnaire on knowledge, attitude, and perception towards allergic reactions of paracetamol

Introduction:

National Pharmaceutical Regulatory Agency, Ministry of Health Malaysia has received 1018 adverse drug reaction reports related to paracetamol with 1972 adverse events from the year 2000 to February 2015. Serious skin reactions including Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis, and acute generalized exanthematous pustulosis may develop as a result of allergic reactions of paracetamol. This study aimed to develop and validate a questionnaire regarding Knowledge, Attitude, and Perception towards Allergic Reactions of Paracetamol (KAP-ARP) among the general population.

Materials and Methods:

Content and face validity of the KAP-ARP were determined by four experts and 20 respondents, respectively. A questionnaire with 36 items, consisting of 16 Knowledge, 9 Attitude, and 11 Perception items, was distributed to 177 respondents. Exploratory factor analysis (EFA) was performed for construct validity. Cronbach’s alpha was used to determine the reliability of the questionnaire.

Results:

EFA constructed 13 Knowledge, 8 Attitude, and 8 Perception items. The final KAP-ARP questionnaire is reliable based on its internal consistency reliability (Knowledge: α = 0.78; Attitude: α = 0.63; Perception: α = 0.70).

Conclusion:

A valid and reliable questionnaire that is useful for measuring KAP-ARP among the general population has been developed.

E-Synthesis: A Bayesian Framework for Causal Assessment in Pharmacosurveillance

Background: Evidence suggesting adverse drug reactions often emerges unsystematically and unpredictably in form of anecdotal reports, case series and survey data. Safety trials and observational studies also provide crucial information regarding the (un-)safety of drugs. Hence, integrating multiple types of pharmacovigilance evidence is key to minimising the risks of harm.

Methods: In previous work, we began the development of a Bayesian framework for aggregating multiple types of evidence to assess the probability of a putative causal link between drugs and side effects. This framework arose out of a philosophical analysis of the Bradford Hill Guidelines. In this article, we expand the Bayesian framework and add “evidential modulators,” which bear on the assessment of the reliability of incoming study results. The overall framework for evidence synthesis, “E-Synthesis”, is then applied to a case study.

Results: Theoretically and computationally, E-Synthesis exploits coherence of partly or fully independent evidence converging towards the hypothesis of interest (or of conflicting evidence with respect to it), in order to update its posterior probability. With respect to other frameworks for evidence synthesis, our Bayesian model has the unique feature of grounding its inferential machinery on a consolidated theory of hypothesis confirmation (Bayesian epistemology), and in allowing any data from heterogeneous sources (cell-data, clinical trials, epidemiological studies), and methods (e.g., frequentist hypothesis testing, Bayesian adaptive trials, etc.) to be quantitatively integrated into the same inferential framework.

Conclusions: E-Synthesis is highly flexible concerning the allowed input, while at the same time relying on a consistent computational system, that is philosophically and statistically grounded. Furthermore, by introducing evidential modulators, and thereby breaking up the different dimensions of evidence (strength, relevance, reliability), E-Synthesis allows them to be explicitly tracked in updating causal hypotheses.

Prescribed analgesics in pregnancy and risk of childhood asthma

Many epidemiological studies have reported a positive association between prenatal exposure to paracetamol and childhood wheezing and asthma. We investigated whether the link between prenatal analgesic exposure and asthma/wheeze is specific to paracetamol, and whether it is causal or confounded.Using linked Swedish health register data we investigated the relation between various prescribed analgesics in pregnancy and the risk of childhood asthma/wheeze in a population of 492 999, and used negative paternal control and sibling comparison approaches to explore unmeasured confounding.After controlling for potential confounders, prescribed opioids, antimigraine drugs and paracetamol were all positively associated with childhood asthma/wheeze risk at all ages (e.g. for asthma/wheeze at age 4 years: adjusted OR 1.39 (95% CI 1.30-1.49), 1.19 (95% CI 1.01-1.40) and 1.47 (95% CI 1.36-1.59) for opioids, antimigraine drugs and paracetamol, respectively). The results of the paternal control analysis did not suggest the presence of unmeasured confounding by genetics or shared environment. However, the sibling control analysis broadly suggested that associations between prenatal exposure to the analgesics and asthma/wheeze were confounded by specific maternal factors (e.g. for asthma/wheeze at age 4 years: adjusted OR 0.91 (95% CI 0.62-1.31), 0.50 (95% CI 0.17-1.45) and 0.80 (95% CI 0.50-1.29) for opioids, antimigraine drugs and paracetamol, respectively).We propose that analgesic use in pregnancy does not cause childhood asthma/wheeze and that the association is confounded by unmeasured factors that are intrinsic to the mother, such as chronic pain or anxiety.

Transplacental transport of paracetamol and its phase II metabolites using the ex vivo placenta perfusion model

In Europe, 50-60% of pregnant women uses paracetamol (PCM), also known as acetaminophen. While it was considered to be safe, recent studies have shown an association between prenatal exposure to PCM and increased incidences of autism, cryptorchidism, asthma and ADHD. In this study the transplacental transfer of PCM and its metabolites was investigated using an ex vivo human placenta perfusion model (closed circuit; n = 38). Maternal-to-foetal (M-F) and foetal-to-maternal (F-M) transplacental transfer was determined at a concentration correlating with the maximum and steady state concentration in normal clinical use. Antipyrine (AP) was added as reference compound. Samples of the foetal and maternal perfusion medium were taken until 210 (PCM) or 360 min (paracetamol sulphate (PCM-S) and paracetamol glucuronide (PCM-G). PCM and AP concentrations reached an equilibrium between foetal and maternal compartments within the duration of the perfusion experiment and irrespective of the transfer direction. The percentage placental transfer of PCM was 45% (M-F and F-M). For PCM-S, transfer was 39% (M-F) and 28% (F-M), while the PCM-G transfer was 34% (M-F) and 25% (F-M). During placenta perfusions with the metabolites slight conversion (3.5-4.1%) to PCM was observed. In conclusion, PCM crosses the placental barrier rapidly via passive diffusion. Differences in flow rate and villous placental structure explain the significantly faster M-F transfer than F-M transfer of PCM. The larger and more hydrophilic molecules PCM-S and PCM-G cross the placenta at a significantly lower rate. Moreover, their F-M transport is about 40% slower than M-F transport, suggesting involvement of a transporter.

Long-term adverse effects of paracetamol - a review

Paracetamol (acetaminophen) is the most commonly used drug in the world, with a long record of use in acute and chronic pain. In recent years, the benefits of paracetamol use in chronic conditions has been questioned, notably in the areas of osteoarthritis and lower back pain. Over the same period, concerns over the long-term adverse effects of paracetamol use have increased, initially in the field of hypertension, but more recently in other areas as well. The evidence base for the adverse effects of chronic paracetamol use consists of many cohort and observational studies, with few randomized controlled trials, many of which contradict each other, so these studies must be interpreted with caution. Nevertheless, there are some areas where the evidence for harm is more robust, and if a clinician is starting paracetamol with the expectation of chronic use it might be advisable to discuss these side effects with patients beforehand. In particular, an increased risk of gastrointestinal bleeding and a small (~4 mmHg) increase in systolic blood pressure are adverse effects for which the evidence is particularly strong, and which show a degree of dose dependence. As our estimation of the benefits decreases, an accurate assessment of the harms is ever more important. The present review summarizes the current evidence on the harms associated with chronic paracetamol use, focusing on cardiovascular disease, asthma and renal injury, and the effects of in utero exposure.

Leptin receptor gene polymorphisms and sex modify the association between acetaminophen use and asthma among young adults: results from two observational studies

Background

Epidemiologic studies have demonstrated associations between acetaminophen use and asthma. This investigation sought to determine whether sex modifies the acetaminophen-asthma association and whether leptin (LEP) and leptin receptor (LEPR) gene polymorphisms modulate the sex-specific associations.

Methods

Data from the Isle of Wight birth cohort (IOW; n = 1456, aged 18 years) and Kuwait University Allergy (KUA; n = 1154, aged 18–26 years) studies were analyzed. Acetaminophen use and current asthma were self-reported. Genotype information for eighteen polymorphisms in LEP and LEPR genes were available in the IOW study. Associations between acetaminophen use and asthma were stratified by sex and genotype. Poisson regression models with robust variance estimation were evaluated to estimate adjusted prevalence ratios (aPR) and 95% confidence intervals (CI).

Results

Acetaminophen use was dose-dependently associated with an increased prevalence of current asthma in the IOW and KUA studies. In both studies, sex-stratified analysis showed that acetaminophen use was associated with asthma among males, but not in females (P_interaction <  0.05). Moreover, a sex- and genotype-stratified analysis of the IOW data indicated that acetaminophen was associated with asthma to a similar extent among males and females carrying two common alleles of LEPR polymorphisms. In contrast, among those carrying at least one copy of the minor allele of LEPR polymorphisms, the magnitude of association between acetaminophen use and asthma was pronounced among males (aPR = 6.83, 95% CI: 2.87–16.24), but not among females (aPR = 1.22, 95% CI: 0.61–2.45).

Conclusions

The identified sex-related effect modification of the acetaminophen-asthma association varied across LEPR genotypes, indicating that the sex-specific association was confined to individuals with certain genetic susceptibility. If the acetaminophen-asthma association is causal, then our findings will aid susceptibility-based stratification of at-risk individuals and augment preventive public health efforts.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0892-y) contains supplementary material, which is available to authorized users.

Role of combined prenatal and postnatal paracetamol exposure on asthma development: the Czech ELSPAC study

BACKGROUND

Prenatal and postnatal paracetamol exposure has been previously associated with asthma development in childhood in Western populations. We explore the association between prenatal and postnatal paracetamol exposure and asthma development in a Central European sample of Czech children, suggesting possible additive effect of the both exposures. Furthermore, since aspirin had been used more widely during study data collection in Central Europe, we also compared asthma development for those exposed to paracetamol and aspirin.

METHODS

We used data from 3329 children born in the 1990s as members of the prospective Czech European Longitudinal Study of Pregnancy and Childhood. Data about prenatal and postnatal paracetamol and aspirin exposure, and potential covariates were obtained from questionnaires completed by mothers. Data about incident asthma were obtained from paediatrician health records.

RESULTS

60.9% of children received paracetamol only postnatally, 1.5% only prenatally and 4.9% of children were exposed both during pregnancy and infancy. Prevalence of asthma in following population was 5% at 11 years. Being exposed to paracetamol both in prenatal and postnatal period was associated with asthma development (unadjusted OR 1.98, 95% CI 1.02 to 3.87). Being exposed only in the postnatal period was also significantly associated with increased risk of asthma. No association between prenatal exposure only and outcome was found. A higher but non-significant risk of asthma was observed for those whose mothers used paracetamol during pregnancy compared with those who used aspirin.

CONCLUSIONS

The main findings of this prospective birth cohort study add to previous observations linking prenatal and early postnatal paracetamol exposure to asthma development. However, the magnitude of effect is relatively modest, and therefore, we recommend paracetamol to remain the analgesic and antipyretic of choice throughout pregnancy and early childhood.

In Utero Exposure to Aspirin and Risk of Asthma in Childhood

BACKGROUND

Aspirin is widely used in general population and low-dose aspirin is commonly prescribed to prevent recurrent pregnancy loss associated with antiphospholipid syndrome and preeclampsia, often used throughout pregnancy. But aspirin is associated with asthma pathogenesis. We aim to examine whether in utero exposure to aspirin at different fetal stages is associated with asthma in childhood.

METHODS

We used data from the Collaborative Perinatal Project. Maternal exposure to aspirin before and during pregnancy was recorded at each prenatal visit. Children were followed up to 7 years of age. A total of 19,928 singleton children without maternal history of asthma were included. We used multilevel multiple logistic regression models to control for potential confounders.

RESULTS

In utero exposure to aspirin was associated with an increased risk of childhood asthma (adjusted odds ratio [aORs] = 1.3, 95% confidence interval [CI] = 1.1, 1.6). aORs for exposure in first, second, and third trimesters were 1.1 (95% CI = 0.87, 1.3), 1.2 (95% CI = 1.0, 1.4), and 1.4 (95% CI = 1.1, 1.6), respectively. Furthermore, aORs of asthma were 1.3 (95% CI = 1.0, 1.7) and 1.3 (95% CI = 1.0, 1.7) for aspirin use for 2 to 7 days or more than 7 days in third trimester, respectively.

CONCLUSION

In utero exposure to therapeutic dose of aspirin even just briefly in late pregnancy is associated with childhood asthma by 7 years of age. More research is needed to carefully examine the association between low-dose aspirin with extended exposure period and long-term child outcomes.

Extrahepatic toxicity of acetaminophen: critical evaluation of the evidence and proposed mechanisms

Research on acetaminophen (APAP) toxicity over the last several decades has focused on the pathophysiology of liver injury, but increasingly attention is paid to other known and possible adverse effects. It has been known for decades that APAP causes acute kidney injury, but confusion exists regarding prevalence, and the mechanisms have not been well investigated. More recently, evidence for pulmonary, endocrine, neurological, and neurodevelopmental toxicity has been reported in a number of published experimental, clinical, and epidemiological studies, but the quality of those studies has varied. It is important to view those data critically due to implications for regulation and clinical practice. Here, we review evidence and proposed mechanisms for extrahepatic adverse effects of APAP and weigh weaknesses and strengths in the available data.

Assessing the impact of in-utero exposures: potential effects of paracetamol on male reproductive development

Human male reproductive disorders (cryptorchidism, hypospadias, testicular cancer and low sperm counts) are common and some may be increasing in incidence worldwide. These associated disorders can arise from subnormal testosterone production during fetal life. This has resulted in a focus on in-utero environmental influences that may result in reproductive effects on the offspring in later life. Over recent years, there has been a dramatic increase in the scientific literature describing associations between in-utero environmental exposures (eg, industrial chemicals and pharmaceuticals) and subsequent reproductive outcomes in male offspring. This includes studies investigating a potential role for in-utero analgesic exposure(s) on the fetal testis; however, providing definitive evidence of such effects presents numerous challenges. In this review, we describe an approach to assessing the potential clinical relevance of in-utero (and postnatal) environmental exposures on subsequent male reproductive function using exposure to the analgesic paracetamol as an example.

Paracetamol Medication During Pregnancy: Insights on Intake Frequencies, Dosages and Effects on Hematopoietic Stem Cell Populations in Cord Blood From a Longitudinal Prospective Pregnancy Cohort

Background

Paracetamol is the first choice for antipyretic or analgesic treatment throughout pregnancy. Products with Paracetamol are readily available over the counter and therefore easily accessible for self-medication. Epidemiological data on Paracetamol intake pattern during pregnancy and its potential immunological effects are sparse. We aimed to analyze a possible association between Paracetamol medication and numbers of hematopoietic stem cells (HSC) in cord blood.

Methods

The objective was addressed in the PRINCE (PRENATAL DETERMINANTS OF CHILDREN'S HEALTH) study, a population-based prospective pregnancy cohort study initiated in 2011 at the University Medical Center in Hamburg, Germany. 518 healthy pregnant women with singleton pregnancies were recruited during the first trimester. Three examinations were scheduled at the end of the 1st (gestational week 12–14), the 2nd (gestational week 22–24) and the 3rd trimester (gestational week 34–36). For 146 of these women, cord blood flow cytometry data were available. Paracetamol intake was assessed for each trimester of pregnancy.

Findings

Among the 518 enrolled women, 40% took Paracetamol as main analgesic treatment during pregnancy. The intake frequency and dosage of Paracetamol varied between the women and was overall low with a tendency towards higher frequencies and higher dosages in the third trimester. Paracetamol intake, particularly during the third trimester, resulted in decreased relative numbers of HSCs in cord blood, independent of maternal age, first-trimester BMI, parity, gestational age and birth weight (− 0.286 (95% CI − 0.592, 0.021), p = 0.068).

Interpretation

Prenatal Paracetamol intake, especially during the third trimester, may be causally involved in decreasing HSCs in cord blood.

•

Paracetamol is the main analgesic agent used during pregnancy.

•

Maternal Paracetamol intake was negatively associated with hematopoietic stem cell frequencies in cord blood.

•

The third trimester seems to be most susceptible for Paracetamol induced reduction of the immune cell progenitors.

Our study focuses on the impact of Paracetamol intake during pregnancy on the offspring's immune development. We were able to show that maternal Paracetamol intake, particularly in the third trimester of pregnancy, was negatively associated with hematopoietic stem cell frequencies in cord blood. These results provide a potential missing link for an association between prenatal Paracetamol medication and childhood disease, particularly asthma, by adding a possible immunological pathway. While we fully acknowledge the medical need of analgesics in pregnancy to prevent or treat more harmful events, our data are valuable for clinical recommendations on self-medication with the OTC drug Paracetamol.

Principles of ear nose and throat surgery for pregnant women

Management of the pregnant surgical patient is challenging. The surgical procedure is usually postponed until the postpartum period, although this may not be possible in emergency situations. This article highlights the optimal management of the pregnant woman requiring ear nose and throat surgery.

Clinical update on benefit versus risks of oral paracetamol alone or with codeine: still a good option?

BACKGROUND

After decades of worldwide use of paracetamol/acetaminophen as a popular and apparently safe prescription and over-the-counter medicine, the future role of this poorly understood analgesic has been seriously questioned by recent concerns about prenatal, cardiovascular (CV) and hepatic safety, and also about its analgesic efficacy. At the same time the usefulness of codeine in combination products has come under debate.

METHODS

Based on a PubMed database literature search on the terms efficacy, safety, paracetamol, acetaminophen, codeine and their combinations up to and including June 2016, this clinical update reviews the current evidence of the benefit and risks of oral paracetamol alone and with codeine for mild-to-moderate pain in adults, and compares the respective efficacy and safety profiles with those of nonsteroidal anti-inflammatory drugs (NSAIDs).

RESULTS

Whereas there is a clear strong association of NSAID use and gastrointestinal (GI) and CV morbidity and mortality, evidence for paracetamol with and without codeine supports the recommended use even in most vulnerable individuals, such as the elderly, pregnant women, alcoholics, and compromised GI and CV patients. The controversies and widespread misconceptions about the complex hepatic metabolism and potential hepatotoxicity have been corrected by recent reviews, and paracetamol remains the first-line nonopioid analgesic in patients with liver diseases if notes of caution are applied.

CONCLUSION

Due to its safety and tolerability profile paracetamol remained a first-line treatment in many international guidelines. Alone and with codeine it is a safe and effective option in adults, whilst NSAIDs are obviously less safe as alternatives, given the risk of potentially fatal GI and CV adverse effects.

A clinical and safety review of paracetamol and ibuprofen in children

The antipyretic analgesics, paracetamol, and non-steroidal anti-inflammatory agents NSAIDs are one of the most widely used classes of medications in children. The aim of this review is to determine if there are any clinically relevant differences in safety between ibuprofen and paracetamol that may recommend one agent over the other in the management of fever and discomfort in children older than 3 months of age.

Association of Acetaminophen and Ibuprofen Use With Wheezing in Children With Acute Febrile Illness

BACKGROUND

Many infants and children receive acetaminophen and/or ibuprofen during febrile illness. Previously, some studies have linked acetaminophen and ibuprofen use to wheezing and exacerbation of asthma symptoms in infants and children.

OBJECTIVE

To assess whether acetaminophen or ibuprofen use are associated with wheezing in children presenting to the emergency department (ED) with febrile illness.

METHODS

This was a cross-sectional study of children who presented with fever to the pediatric ED between 2009 and 2013. The data were collected from questionnaires and from the children's medical files. Patients with wheezing in the ED were compared with nonwheezing patients. Associations between medication use and wheezing were assessed using univariate and multivariate analyses. The multivariate analysis adjusted for potential confounding variables (ie, age, atopic dermatitis, allergies, smoking, antibiotics use, etc) via propensity scores.

RESULTS

During the study period, 534 children admitted to the ED met our inclusion criteria, of whom 347 (65%) were included in the study. The use of acetaminophen was similar in children diagnosed with wheezing compared with those without wheezing (n = 39, 81.3%, vs n = 229, 82.7%, respectively). Ibuprofen use was significantly lower in children diagnosed with wheezing (n = 22, 52.4%, vs n = 168, 69.4%, respectively). In multivariate analysis, acetaminophen was not associated with a higher rate of wheezing during acute febrile illness (adjusted odds ratio [OR] = 0.76, 95% CI = 0.24- 2.39), whereas ibuprofen was associated with a lower risk of wheezing (adjusted OR = 0.36, 95% CI = 0.13-0.96).

CONCLUSIONS

Our study suggests that acetaminophen and ibuprofen are not associated with increased risk for wheezing during acute febrile illness.

Prenatal paracetamol exposure is associated with shorter anogenital distance in male infants

STUDY QUESTION

What is the relationship between maternal paracetamol intake during the masculinisation programming window (MPW, 8-14 weeks of gestation) and male infant anogenital distance (AGD), a biomarker for androgen action during the MPW?

SUMMARY ANSWER

Intrauterine paracetamol exposure during 8-14 weeks of gestation is associated with shorter AGD from birth to 24 months of age.

WHAT IS ALREADY KNOWN

The increasing prevalence of male reproductive disorders may reflect environmental influences on foetal testicular development during the MPW. Animal and human xenograft studies have demonstrated that paracetamol reduces foetal testicular testosterone production, consistent with reported epidemiological associations between prenatal paracetamol exposure and cryptorchidism.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study (Cambridge Baby Growth Study), with recruitment of pregnant women at ~12 post-menstrual weeks of gestation from a single UK maternity unit between 2001 and 2009, and 24 months of infant follow-up. Of 2229 recruited women, 1640 continued with the infancy study after delivery, of whom 676 delivered male infants and completed a medicine consumption questionnaire.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Mothers self-reported medicine consumption during pregnancy by a questionnaire administered during the perinatal period. Infant AGD (measured from 2006 onwards), penile length and testicular descent were assessed at 0, 3, 12, 18 and 24 months of age, and age-specific Z scores were calculated. Associations between paracetamol intake during three gestational periods (<8 weeks, 8-14 weeks and >14 weeks) and these outcomes were tested by linear mixed models. Two hundred and twenty-five (33%) of six hundred and eighty-one male infants were exposed to paracetamol during pregnancy, of whom sixty-eight were reported to be exposed during 8-14 weeks. AGD measurements were available for 434 male infants.

MAIN RESULTS AND THE ROLE OF CHANCE

Paracetamol exposure during 8-14 weeks of gestation, but not any other period, was associated with shorter AGD (by 0.27 SD, 95% CI 0.06-0.48, P = 0.014) from birth to 24 months of age. This reduction was independent of body size. Paracetamol exposure was not related to penile length or testicular descent.

LIMITATIONS, REASONS FOR CAUTION

Confounding by other drugs or endocrine-disrupting chemicals cannot be discounted. The cohort was not fully representative of pregnant women in the UK, particularly in terms of maternal ethnicity and smoking prevalence. There is likely to have been misclassification of paracetamol exposure due to recall error.

WIDER IMPLICATIONS OF THE FINDINGS

Our observational findings support experimental evidence that intrauterine paracetamol exposure during the MPW may adversely affect male reproductive development.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by a European Union Framework V programme, the World Cancer Research Fund International, the Medical Research Council (UK), the Newlife Foundation for Disabled Children, the Evelyn Trust, the Mothercare Group Foundation, Mead Johnson Nutrition, and the National Institute for Health Research Cambridge Comprehensive Biomedical Research Centre. The authors declare no conflict of interest.

The association between paracetamol and asthma is still under debate

OBJECTIVE

To analyse the relationship between paracetamol and asthma.

DATA SOURCES

An English literature search using electronic search engines (PubMed and EMBASE) was conducted.

STUDY SELECTIONS

Articles published in peer-review journals, from 1990 to December 2015 were included. To perform the search for the most suitable and representative articles, keywords were selected ("asthma," "paracetamol" and "acetaminophen"). The evidence level was rated according to the criteria of the Oxford Centre For Evidence-Based Medicine.

RESULTS

The exposure to paracetamol during pregnancy was analysed in several cohort studies, showing an association between the prenatal exposure to paracetamol with suffering from asthma or presence of wheezing in childhood, especially for persistent wheezing. Nevertheless, a recent study concluded that the relationship between asthma and paracetamol is explained, at least in part, by confounding factors. Several works have also associated the exposure to paracetamol in the first years of life or in adults with the development of childhood asthma. Several pathophysiological mechanisms are known that could explain this relationship, such as the glutathione pathway, the decrease in the release of Th1 cytokines that are normally produced during febrile episodes, which would then lead to a predominance of Th2 cytokines, the cytotoxic effect of paracetamol for pneumocytes, a modulator effect on the activity of myeloperoxidase, as well as the possible antigenic effect of paracetamol, mediated by IgE.

CONCLUSIONS

There are many arguments that suggest a relationship between the use of paracetamol with the appearance of asthmatic symptoms, however the evidence is inconclusive.

Prenatal and early-life predictors of atopy and allergic disease in Canadian children: results of the Family Atherosclerosis Monitoring In earLY life (FAMILY) Study

Prenatal and early-life environmental exposures play a key role in the development of atopy and allergic disease. The Family Atherosclerosis Monitoring In earLY life Study is a general, population-based Canadian birth cohort that prospectively evaluated prenatal and early-life traits and their association with atopy and/or allergic disease. The study population included 901 babies, 857 mothers and 530 fathers. Prenatal and postnatal risk factors were evaluated through questionnaires collected during the antenatal period and at 1 year. The end points of atopy and allergic diseases in infants were evaluated through questionnaires and skin prick testing. Key outcomes included atopy (24.5%), food allergy (17.5%), cow’s milk allergy (4.8%), wheezing (18.6%) and eczema (16%). The association between infant antibiotic exposure [odds ratio (OR): 2.04, 95% confidence interval (CI): 1.45–2.88] and increased atopy was noted in the multivariate analysis, whereas prenatal maternal exposure to dogs (OR: 0.60, 95% CI: 0.42–0.84) and acetaminophen (OR: 0.68, 95% CI: 0.51–0.92) was associated with decreased atopy. This population-based birth cohort in Canada demonstrated high rates of atopy, food allergy, wheezing and eczema. Several previously reported and some novel prenatal and postnatal exposures were associated with atopy and allergic diseases at 1 year of age.

Biomonitoring of prenatal analgesic intake and correlation with infantile anti-aeroallergens IgE

An association between prenatal acetaminophen or ibuprofen intake and an increased risk of asthma and increased IgE level in children is discussed in various epidemiological studies. Although the molecular mechanistic link is still unknown, the question whether or not acetaminophen and/or ibuprofen are safe pain medications during pregnancy arose. In this study, we associate maternal acetaminophen and ibuprofen intake during pregnancy and breastfeeding to infantile asthma phenotypes and elevated IgE level. Therefore, we analysed questionnaires from a local mother-child cohort and monitored drug intake by LC-MS biomonitoring in urine. No association was found between drug intake and any analysed health outcome using questionnaire data. For the information obtained from biomonitoring, no association was found for ibuprofen and acetaminophen intakes during breastfeeding. However, an association between prenatal acetaminophen intake and increased infantile IgEs related to aeroallergens was statistically detected, but not for asthma phenotypes.

Association of prenatal exposure to acetaminophen and coffee with childhood asthma

PURPOSE

Some studies have suggested that maternal acetaminophen use during pregnancy is associated with asthma in the offspring, and coffee consumption may modify the toxicity of acetaminophen. We aim to examine whether pregnancy maternal acetaminophen use increases the risk for offspring asthma, and whether such a potential association could be modified by maternal coffee consumption.

METHODS

We included 63,652 live-born singletons enrolled in the Danish National Birth Cohort. Maternal acetaminophen use and coffee consumption during pregnancy were assessed prospectively via the enrolment questionnaire and three computer-assisted telephone interviews. Asthma cases were identified by using the Danish National Patient Register and the Danish National Prescription Registry. We estimated the hazard ratios (HRs) for asthma according to prenatal acetaminophen and coffee exposure using Cox proportional hazards regression model.

RESULTS

After adjusting for potential confounders, acetaminophen use during pregnancy was associated with an increased risk of offspring asthma (HR = 1.16, 95% confidence interval (CI): 1.11-1.22). Coffee drinking during pregnancy was associated with a slightly decreased risk (HR = 0.94, 95%CI: 0.90-0.99). But there was no strong evidence of effect measure modification of acetaminophen use on offspring asthma by coffee consumption.

CONCLUSIONS

Acetaminophen use during pregnancy was associated with a modest increased risk for offspring asthma, which was not modified by coffee consumption.

Randomized controlled trial of asthma risk with paracetamol use in infancy--a feasibility study

BACKGROUND

There is non-experimental evidence that paracetamol (acetaminophen) use may increase the risk of developing asthma. However, numerous methodological issues need to be resolved before undertaking a randomized controlled trial to investigate this hypothesis.

OBJECTIVE

To establish the feasibility of a randomized controlled trial of liberal paracetamol as usually given by parents/guardians vs. a comparator (restricted paracetamol in accordance with WHO guidelines, ibuprofen or placebo), and childhood asthma risk.

METHODS

Questionnaires were completed by parents/guardians of infants admitted to Wellington Hospital with bronchiolitis to assess views about comparator treatments. Subsequently, infants of parents/guardians who provided informed consent were randomized to restricted or liberal paracetamol use for 3 months with paracetamol use recorded.

RESULTS

Of 120 eligible participants, 72 (60%) parents/guardians completed the questionnaire. Ibuprofen, restricted paracetamol and placebo were acceptable to 42 (58%), 29 (40%) and 9 (12%) parents/guardians, respectively. 36 (30%) infants were randomized to restricted or liberal paracetamol. Paracetamol use was greater for the liberal vs. restricted group for reported [Hodges-Lehmann estimator of difference 0.94 mg/kg/day (95% CI 0.2-3.52), P = 0.02] and measured use [Hodges-Lehmann estimator of difference 2.11 mg/kg/day (95% CI 0.9-4.18), P = 0.004]. The median reported and measured use of paracetamol was 2.0-fold and 3.5-fold greater in the liberal vs. restricted group.

CONCLUSIONS AND CLINICAL RELEVANCE

Although separation in paracetamol dosing is likely to be achieved with a liberal vs. restricted paracetamol regime, ibuprofen is the preferred comparator treatment in the proposed RCT of paracetamol use and risk of asthma in childhood.

The association between paracetamol use and asthma: causation or coincidence?

A better understanding of the causation of asthma and allergic disorders could potentially lead to intervention strategies that reduce their prevalence and severity. One potential causative factor is the use of paracetamol. Most of the evidence for the link with asthma is from non-experimental studies of paracetamol exposure in utero, infancy, childhood and adult life; however, it has been difficult to rule out confounding and bias in the associations observed. The two randomized clinical trials of the effect of paracetamol in patients with asthma have been difficult to interpret, due to methodological issues. There have been no randomized controlled trials of paracetamol use and the development of asthma. Both asthma and paracetamol use are common, and so even if there is a relatively small effect of paracetamol exposure on the development of asthma or its severity, then such an effect would be of major public health significance. It is proposed that randomized controlled trials of the effect of paracetamol on the development of asthma and its severity are a high research priority.

Prenatal Paracetamol Exposure and Wheezing in Childhood: Causation or Confounding?

Background

Several studies have reported an increased risk of wheezing in the children of mothers who used paracetamol during pregnancy. We evaluated to what extent this association is explained by confounding.

Methods

We investigated the association between maternal paracetamol use in the first and third trimester of pregnancy and ever wheezing or recurrent wheezing/asthma in infants in the NINFEA cohort study. Risks ratios (RR) and 95% confidence intervals (CI) were estimated after adjustment for confounders, including maternal infections and antibiotic use during pregnancy.

Results

The prevalence of maternal paracetamol use was 30.6% during the first and 36.7% during the third trimester of pregnancy. The prevalence of ever wheezing and recurrent wheezing/asthma was 16.9% and 5.6%, respectively. After full adjustment, the RR for ever wheezing decreased from 1.25 [1.07–1.47] to 1.10 [0.94–1.30] in the first, and from 1.26 [1.08–1.47] to 1.10 [0.93–1.29] in the third trimester. A similar pattern was observed for recurrent wheezing/asthma. Duration of maternal paracetamol use was not associated with either outcome. Further analyses on paracetamol use for three non-infectious disorders (sciatica, migraine, and headache) revealed no increased risk of wheezing in children.

Conclusion

The association between maternal paracetamol use during pregnancy and infant wheezing is mainly, if not completely explained by confounding.

Perinatal paracetamol exposure in mice does not affect the development of allergic airways disease in early life

Background

Current data concerning maternal paracetamol intake during pregnancy, or intake during infancy and risk of wheezing or asthma in childhood is inconclusive based on epidemiological studies. We have investigated whether there is a causal link between maternal paracetamol intake during pregnancy and lactation and the development of house dust mite (HDM) induced allergic airways disease (AAD) in offspring using a neonatal mouse model.

Methods

Pregnant mice were administered paracetamol or saline by oral gavage from the day of mating throughout pregnancy and/or lactation. Subsequently, their pups were exposed to intranasal HDM or saline from day 3 of life for up to 6 weeks. Assessments of airway hyper-responsiveness, inflammation and remodelling were made at weaning (3 weeks) and 6 weeks of age.

Results

Maternal paracetamol exposure either during pregnancy and/or lactation did not affect development of AAD in offspring at weaning or at 6 weeks. There were no effects of maternal paracetamol at any time point on airway remodelling or IgE levels.

Conclusions

Maternal paracetamol did not enhance HDM induced AAD in offspring. Our mechanistic data do not support the hypothesis that prenatal paracetamol exposure increases the risk of childhood asthma.

Acetaminophen: old drug, new issues

INTRODUCTION

The purpose of this review was to discuss new issues related to safety, labeling, dosing, and a better understanding of the analgesic effect of acetaminophen.

METHODS

The MEDLINE, Embase, Cochrane, and PubMed databases were searched. Additionally, the bibliography of all relevant articles and textbooks were manually searched. Two reviewers independently selected the relevant articles.

RESULTS

Concerns about acetaminophen overdose and related liver failure have led the US Food and Drug Administration to mandate new labeling on acetaminophen packaging. In addition, large-scale epidemiologic studies increasingly report evidence for second-generation adverse effects of acetaminophen. Prenatal exposure to acetaminophen is associated with neurodevelopmental and behavioral disorders. Recent studies also suggest that acetaminophen is a hormone disrupter (ie, it interferes with sex and thyroid hormone function essential for normal brain development) and thus may not be considered a safe drug during pregnancy. Finally, emerging evidence suggests that although the predominant mechanism by which acetaminophen exerts its therapeutic effect is by inhibition of cyclooxygenase, multiple other mechanisms also contribute to its analgesic effect.

CONCLUSIONS

Available evidence suggests that indiscriminate usage of this drug is not warranted. and its administration to a pregnant patient should be considered with great caution.

Babies Galore; or recent findings and future perspectives of pregnancy cohorts with a focus on immunity

Population-based pregnancy cohorts recruiting women before or at the moment of childbirth allow a longitudinal follow-up on children's health later in life. Important findings arising from pregnancy cohorts are discussed in the present review. These insights have led to revised guidelines on how to minimize disease risks in children, e.g., in the context of chronic immune diseases including allergies and asthma. Moreover, insights from pregnancy cohorts also unveiled a collateral effect of pregnancy on maternal immunity, mirrored by an ameliorated course of certain autoimmune diseases, but also an increased risk of infection with influenza A virus. Future pregnancy cohort studies are still required to close gaps in knowledge on how parameters involved in the developmental origin of health or poor immunity observed in children later in life are operational. We discuss here features that should be covered by future pregnancy cohort studies. Expected insights from such studies will then lay the foundation for biomarker discovery and offer opportunities for interventions to ameliorate adverse immune responses in humans.

Paracetamol exposure in pregnancy and early childhood and development of childhood asthma: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

While paracetamol exposure in pregnancy and early infancy has been associated with asthma, it remains unclear whether this is confounded by respiratory tract infections, which have been suggested as an alternative explanation. We undertook a systematic review and meta-analysis of longitudinal studies that reported the association between paracetamol exposure during pregnancy or infancy and the subsequent development of childhood asthma (≥5 years).

METHODS

Two independent researchers searched the databases EMBASE and PUBMED on 12 August 2013 for relevant articles using predefined inclusion and exclusion criteria. Study quality was assessed and results were pooled using fixed effect models or random effect models when moderate between-study heterogeneity was observed. We explicitly assessed whether the observed associations are due to confounding by respiratory tract infections.

RESULTS

Eleven observational cohort studies met the inclusion criteria. Any paracetamol use during the first trimester was related to increased risk of childhood asthma (5 studies, pooled OR=1.39, 95% CI 1.01 to 1.91) but there was marked between-study heterogeneity (I(2)=63%) and only one of these studies adjusted for maternal respiratory tract infections. Increasing frequency of use of paracetamol during infancy was associated with increased odds of childhood asthma (3 studies, pooled OR=1.15, 95% CI 1.00 to 1.31 per doubling of days exposure), but in these same three studies adjusting for respiratory tract infections reduced this association (OR=1.06, 95% CI 0.92 to 1.22).

DISCUSSION

The association during early pregnancy exposure was highly variable between studies and exposure during infancy appears to be moderately confounded by respiratory tract infections. There is insufficient evidence to warrant changing guidelines on early life paracetamol exposure at this time.

Prenatal and infant exposure to acetaminophen and ibuprofen and the risk for wheeze and asthma in children

BACKGROUND

Several studies have reported an association between use of over-the-counter antipyretics during pregnancy or infancy and increased asthma risk. An important potential limitation of these observational studies is confounding by indication.

OBJECTIVES

We investigated the association of antipyretic intake during pregnancy and during the first year of life (infancy) with asthma-related outcomes before and after controlling for early-life respiratory tract infections.

METHODS

We included 1490 mother-child pairs in Project Viva, a longitudinal prebirth cohort study. We categorized prenatal acetaminophen exposure as the maximum intake (never, 1-9 times, or ≥10 times) in early pregnancy or midpregnancy and ibuprofen intake as presence or absence in early pregnancy. We expressed intake of antipyretics in infancy as never, 1 to 5 times, 6 to 10 times, or more than 10 times. We examined the associations of acetaminophen and ibuprofen (per unit increase in exposure category) during pregnancy and infancy with wheeze, asthma, and allergen sensitization in early childhood (3-5 years of age, n = 1419) and midchildhood (7-10 years of age, n = 1220).

RESULTS

Unadjusted models showed an increased asthma risk in early childhood for higher infant acetaminophen (odds ratio [OR], 1.21; 95% CI 1.04-1.41) and ibuprofen (OR, 1.35; 95% CI, 1.19-1.52) intake. Controlling for respiratory tract infections attenuated estimates for acetaminophen (OR, 1.03; 95% CI, 0.88-1.22) and ibuprofen (OR, 1.19; 95% CI, 1.05-1.36). Prenatal acetaminophen was associated with increased asthma (OR, 1.26; 95% CI, 1.02-1.58) in early childhood but not midchildhood.

CONCLUSIONS

Adjustment for respiratory tract infections in early life substantially diminished associations between infant antipyretic use and early childhood asthma. Respiratory tract infections should be accounted for in studies of antipyretics and asthma to mitigate bias caused by confounding by indication.

Prevention of asthma: where are we in the 21st century?

Asthma is the most common chronic disease of childhood and, in the latter part of the 20th century, reached epidemic proportions. Asthma is generally believed to result from gene-environment interactions. There is consensus that a 'window of opportunity' exists during pregnancy and early in life when environmental factors may influence its development. We review multiple environmental, biologic and sociologic factors that may be important in the development of asthma. Meta-analyses of studies have demonstrated that multifaceted interventions are required in order to develop asthma prevention. Multifaceted allergen reduction studies have shown clinical benefits. Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma also may be an indication of increased population risk for the development of other chronic non-communicable autoimmune diseases. This review will focus on the factors which may be important in the primary prevention of asthma. Better understanding of the complex gene-environment interactions involved in the development of asthma will provide insight into personalized interventions for asthma prevention.

Acetaminophen and/or antibiotic use in early life and the development of childhood allergic diseases

BACKGROUND

Our understanding of whether the use of acetaminophen and/or antibiotics in early life can cause allergic diseases in later childhood remains inconclusive. The objective of this study was to investigate the temporal relationship between exposure to acetaminophen and/or antibiotics in early life and the development of allergic diseases in later childhood, using two independent birth cohorts derived from the National Health Insurance Research Database (NHIRD) in Taiwan.

METHODS

The authors conducted a prospective birth cohort study of 263 620 children born in 1998 and 9910 children born in 2003, separately, from the NHIRD. Exposure status of acetaminophen and/or antibiotics and potential confounding factors were included in the analyses. Cox proportional hazards models were applied to determine the temporal relationship between acetaminophen and/or antibiotic exposure and the development of allergic diseases.

RESULTS

We observed a positive relationship between acetaminophen and/or antibiotic exposure during the 1st year of life and the subsequent development of the three examined allergic diseases (atopic dermatitis, asthma and allergic rhinitis) in the 1998 birth cohort, but the observed relationship of drug exposure in the 2003 cohort, especially for atopic dermatitis and asthma, was lower than for those in the 1998 cohort and was not statistically significant.

CONCLUSIONS

Our findings provide suggestive evidence that the temporal effect of exposure to acetaminophen and/or antibiotics influences the development of common allergic diseases in later childhood. Further functional studies and/or animal studies are needed to better understand the underlying regulatory mechanisms driving this important clinical and public health issue.

Association between recent acetaminophen use and asthma: modification by polymorphism at TLR4

The risk of asthma has been increasing in parallel with use of acetaminophen, which is a potential source of oxidative stress. Toll-like receptor 4 (TLR4) plays a critical role not only in innate immunity, but also in mediating reactive oxygen species induced inflammation. Therefore, we investigated associations between acetaminophen usage and TLR4 polymorphism on asthma and bronchial hyperresponsiveness (BHR). The number of 2,428 elementary school children in Seoul and Jeongeup cities was recruited. Subjects who used acetaminophen with a family history of asthma had an increased risk of both asthma diagnosis ever and current asthma. Individuals with CT+TT genotypes at the TLR4 polymorphism, in combination with acetaminophen usage, also demonstrated an increased risk of asthma diagnosis ever (aOR, 2.08; 95% confidence interval [CI], 1.10-3.92). Family history of asthma and acetaminophen usage were risk factors for BHR. Although TLR4 was not an independent risk factor for BHR, individuals with CT+TT genotypes at the TLR4 polymorphism had an increased risk of BHR when combined with acetaminophen usage (aOR, 1.74; 95% CI, 1.03-2.94). In conclusion, acetaminophen usage may be associated with asthma and BHR in genetically susceptible subjects. This effect may be modified by polymorphism at TLR4.

Effects of early life paracetamol use on the incidence of allergic disease and sensitization: 5 year follow-up of an Ethiopian birth cohort

INTRODUCTION

The hypothesis that paracetamol, one of the most widely used medicines, may increase the risk of asthma and allergic disease is of obvious importance but prospective cohort data looking at dose and timing of exposure are lacking.

OBJECTIVE

The aim of the study is to investigate the role of paracetamol use in early life on the prevalence and incidence of wheeze, eczema, rhinitis and allergic sensitization, prospectively over 5 years in an Ethiopian birth cohort.

METHODS

In 2005/6 a birth cohort of 1006 newborns was established in Butajira, Ethiopia. Questionnaire data on allergic disease symptoms, paracetamol use and numerous potential confounders were collected at ages 1, 3 and 5, and allergen skin sensitivity measured at ages 3 and 5. Multivariate logistic regression was used to determine independent effects of paracetamol exposure on the incidence of each outcome between ages 3 and 5, and prevalence at age 5.

FINDINGS

Paracetamol use in the first 3 years of life was reported in 60% of children and was associated with increased incidence of wheeze, eczema, rhinitis and allergic sensitisation between ages 3 and 5 which was statistically significant for wheeze and eczema. High exposure (reported use in the past month at age 1 and 3) was associated with a more than 3-fold increased risk of new onset wheeze (adjusted odds ratio (OR) 3.64; 95% confidence interval, 1.34 to 9.90) compared to never users. Use in the past year at age 3 but not age 1 was associated with ORs at least as large as those for use in first year of life only. Significant positive dose-response effects of early life use were seen in relation to the prevalence of all outcomes at age 5.

CONCLUSIONS

Use of paracetamol in early life is a strong risk factor for incident allergic disease in childhood.

Randomised placebo-controlled study of the effect of paracetamol on asthma severity in adults

OBJECTIVE

To investigate the effect of regular paracetamol on bronchial hyper-responsiveness (BHR) and asthma control in adult asthma.

SETTING

Single research-based outpatient clinic.

PARTICIPANTS

94 adults with mild-to-moderate asthma received randomised treatment; 85 completed the study. Key inclusion criteria were age 18-65 years, forced expiratory volume in 1 s (FEV1) >70% predicted, provocation concentration of methacholine causing a 20% reduction in FEV1 (PC20) between 0.125 and 16 mg/mL. Key exclusion criteria included an asthma exacerbation within the previous 2 months, current regular use of paracetamol, use of high-dose aspirin or non-steroidal anti-inflammatory drugs, current or past cigarette smoking >10 pack-years.

INTERVENTIONS

In a 12-week randomised, double-blind, placebo-controlled, parallel-group study, participants received 12 weeks of 1 g paracetamol twice daily or placebo twice daily.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome variable was BHR, measured as the PC20 at week 12. Secondary outcome variables included FEV1, fractional exhaled nitric oxide (FeNO) and asthma control questionnaire (ACQ) score.

RESULTS

At 12 weeks, the mean (SD) logarithm base two PC20 was 1.07 (2.36) in the control group (N=54) and 0.62 (2.09) in the paracetamol group (N=31). After controlling for baseline PC20, the mean difference (paracetamol minus placebo) was -0.48 doubling dose worsening in BHR in the paracetamol group (95% CI -1.28 to 0.32), p=0.24. There were no statistically significant differences (paracetamol minus placebo) in log FeNO (0.09 (95% CI -0.097 to 0.27)), FEV1 (-0.07 L (95% CI -0.15 to 0.01)) or ACQ score (-0.04 (95% CI -0.27 to 0.18)).

CONCLUSIONS

There was no significant effect of paracetamol on BHR and asthma control in adults with mild-to-moderate asthma. However, the study findings are limited by low power and the upper confidence limits did not rule out clinically relevant adverse effects.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry Number: NZCTR12609000551291.