Neonatal Toxicity Research Articles

Exploring the Impact of Developmental Clearance Saturation on Propylene Glycol Exposure in Adults and Term Neonates Using Physiologically Based Pharmacokinetic Modeling.

Propylene glycol (PG) is a pharmaceutical excipient which is generally regarded as safe (GRAS), though clinical toxicity has been reported. PG toxicity has been attributed to accumulation due to saturation of the alcohol dehydrogenase (ADH)-mediated clearance pathway. This study aims to explore the impact of the saturation of ADH-mediated PG metabolism on its developmental clearance in adults and neonates and assess the impact of a range of doses on PG clearance saturation and toxicity. Physiologically based pharmacokinetic (PBPK) models for PG in adults and term neonates were developed using maximum velocity (Vmax) and Michaelis-Menten's constant (Km) of ADH-mediated metabolism determined in vitro in human liver cytosol, published physicochemical, drug-related and ADH ontogeny parameters. The models were validated and used to determine the impact of dosing regimen on PG clearance saturation and toxicity in adults and neonates. The Vmax and Km of PG in human liver cytosol were 1.57 nmol/min/mg protein and 25.1 mM, respectively. The PG PBPK model adequately described PG PK profiles in adults and neonates. The PG dosing regimens associated with saturation and toxicity were dependent on both dose amount and cumulative in standard dosing frequencies. Doses resulting in saturation were higher than those associated with clinically observed toxicity. In individuals without impaired clearance or when PG exposure is through formulations that contain excipients with possible interaction with PG, a total daily dose of 100-200 mg/kg/day in adults and 25-50 mg/kg/day in neonates is unlikely to result in toxic PG levels or PG clearance saturation.

Neonatal Near Fatal Flecainide Toxicity

Background: Flecainide is an anti-arrhythmic medication with a narrow therapeutic index and a high mortality rate, when overdosed. Few cases of flecainide toxicity in neonates and children due to medication error have been reported in the literature. A case of an accidental flecainide overdose in a neonate in Oman was presented. Case Presentation: A 19-day-old newborn girl developed persistent supra ventricular tachycardia (SVT) after receiving nebulized albuterol for acute bronchitis. After unsuccessful treatment with adenosine, she was given flecainide 5.6 mg orally every 24 hours for resolution of the SVT. On day four of admission, the child inadvertently received 100 mg of flecainide orally due to a dose calculation error. The child developed wide complex tachyarrhythmia followed by pulseless ventricular tachycardia (VT) requiring cardiopulmonary resuscitation. Sodium bicarbonate IV bolus followed by an infusion was administered. The patient developed two additional episodes of pulseless VT that coincided temporally with two interruptions of the sodium bicarbonate infusion, and required high dose of inotropic support. The patient developed convulsions but her brain ultrasound was normal. Her condition stabilized on day three after the toxicity occurred. Repeated echo showed a normal EF. The patient was discharged on propranolol and levetiracetam and was doing well on outpatient follow up. Conclusion: Flecainide is a potentially lethal medication in overdose due to its sodium channel blocking properties. Sodium bicarbonate remains an essential component of treatment.

An Assessment of aluminum contamination in neonatal parenteral nutrition solutions based on measured versus labeled content

Aluminum can potentially cause toxicity in pediatrics and neonates receiving parenteral nutrition. Some PN solutions and ingredients in Saudi Arabia do not comply with US FDA regulations regarding aluminum exposure. This study aims to determine the aluminum concentration in samples of PN solutions and ingredients used to feed infants in Saudi Arabia. The aluminum in the samples was determined using inductively coupled plasma mass spectrometry. The concentration of metal contaminants in each sample was determined in triplicate. The aluminum content of 38 samples was investigated, 15 of which originated from components included in the prepared PN solutions. Among the 15 samples, the least measurable aluminum content was detected in potassium chloride solutions (0.81 mcg/L). In contrast, the greatest amount of aluminum was detected in potassium phosphate and calcium gluconate (141,64 mcg/L and 462.7 mcg/L), respectively. The results showed that the final PN solution (PNS) product contained more aluminum levels than the content ingredients; in addition, the study found a statistically significant relationship among 18 pediatric patients at KFMC who had intestinal failure and needed long-term parenteral nutrition. Specifically, their high aluminum levels, exceeding the normal range of 0.6 ng/ml, indicate that the current use of PN solutions will likely cause toxicity due to aluminum contamination in additives. Hence, reducing aluminum in PN solutions is imperative to ensure patient safety.

Salivary therapeutic monitoring of methadone toxicity in neonates after transplacental transfer from parturient mothers treated with oral methadone guided by PBPK modeling

Opioid use disorders (OUD) during pregnancy are related to neonatal opioid withdrawal syndrome (NOWS). R,S-methadone used to treat OUD and NOWS can penetrate the placenta. High neonatal brain extracellular fluid (bECF) levels of R,S-methadone can induce respiratory depression in newborns. The purpose of this work was to estimate neonatal bECF and saliva levels to establish the neonatal R,S-methadone salivary thresholds for respiratory depression after maternal oral dosing despite the sparse data in pregnancy and newborn populations. An adult physiologically-based pharmacokinetic (PBPK) model for R,S-methadone after intravenous and oral administration was constructed, vetted, and scaled to newborn and pregnancy populations. The pregnancy model predicted the R-methadone and S-methadone doses transplacentally transferred to newborns. Then, the newborn PBPK model was used to estimate newborn exposure after such doses. After maternal oral dosing of R,S-methadone (43.8 mg/day), the neonatal plasma levels were below the respiratory depression threshold. Further, the bECF levels were above the analgesia threshold for more than 96 h. The salivary thresholds for the analgesic effects of R-methadone, S-methadone, and R,S-methadone were estimated herein at 1.7, 43, and 16 ng/mL, respectively. Moreover, the salivary thresholds for the respiratory depression of R-methadone and R,S-methadone were estimated at 58 and 173 ng/mL, respectively. Using neonatal salivary monitoring of methadone can be useful in ensuring newborns' safety during maternal OUD treatment.

Cutting without a Knife: A Slice-Selective 2D 1H-13C HSQC NMR Sequence for the Analysis of Inhomogeneous Samples.

Nuclear magnetic resonance (NMR) is a powerful technique with applications ranging from small molecule structure elucidation to metabolomics studies of living organisms. Typically, solution-state NMR requires a homogeneous liquid, and the whole sample is analyzed as a single entity. While adequate for homogeneous samples, such an approach is limited if the composition varies as would be the case in samples that are naturally heterogeneous or layered. In complex samples such as living organisms, magnetic susceptibility distortions lead to broad 1H line shapes, and thus, the additional spectral dispersion afforded by 2D heteronuclear experiments is often required for metabolite discrimination. Here, a novel, slice-selective 2D, 1H-13C heteronuclear single quantum coherence (HSQC) sequence was developed that exclusively employs shaped pulses such that only spins in the desired volume are perturbed. In turn, this permits multiple volumes in the tube to be studied during a single relaxation delay, increasing sensitivity and throughput. The approach is first demonstrated on standards and then used to isolate specific sample/sensor elements from a microcoil array and finally study slices within a living earthworm, allowing metabolite changes to be discerned with feeding. Overall, slice-selective NMR is demonstrated to have significant potential for the study of layered and other inhomogeneous samples of varying complexity. In particular, its ability to select subelements is an important step toward developing microcoil receive-only arrays to study environmental toxicity in tiny eggs, cells, and neonates, whereas localization in larger living species could help better correlate toxin-induced biochemical responses to the physical localities or organs involved.

Safety profile of monoclonal antibodies targeting the calcitonin gene-related peptide system in pregnancy: Updated analysis in VigiBase®.

Safety data on the use of migraine preventive monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) system in pregnancy are limited. Updated pharmacovigilance assessment of the safety reports related to pregnancy associated with erenumab, galcanezumab, fremanezumab and eptinezumab, retrieved from VigiBase® as of 31 December 2021. As primary outcome, the whole group of monoclonal antibodies targeting the CGRP system was considered and sex and age subgroup disproportionality analyses using the reporting odds ratio (ROR) were conducted. 286 safety reports were found: 116 (40.6%) on erenumab, 125 (43.7%) on galcanezumab, 39 (13.6%) on fremanezumab, 6 (2.1%) on eptinezumab. One hundred and forty-nine (52.1%) safety reports reported only drug exposure in relation to pregnancy while 137 (47.9%) also included ≥1 pregnancy outcomes: maternal outcomes (n = 64), spontaneous abortion (n = 63), foetal growth restriction (n = 1), prematurity (n = 8), neonatal outcomes (n = 13), and poor breastfeeding (n = 1). No specific patterns of maternal, foetal and neonatal toxicity were observed. Spontaneous abortion was not disproportionally more frequently reported with erenumab, galcanezumab, fremanezumab and eptinezumab compared with the entire database (ROR 1.1, 95% confidence interval, CI, 0.8-1.5), the entire database since 2018 (ROR 1.3, 95% CI 1.0-1.8), and triptans (ROR 1.2, 95% CI 0.8-1.9). This updated safety analysis on erenumab, galcanezumab, fremanezumab and eptinezumab in pregnancy showed no signals of foeto-maternal toxicity according to VigiBase® safety reports.

The potentially harmful excipients in prescribed medications in a Neonatal Intensive Care Unit in Kosovo and available safer alternatives

Medicinal products contain excipients that might be associated with toxicity in neonates. The aim of this study was to investigate the administration of medication containing potentially harmful excipients to neonates hospitalized in Kosovo and to identify the possibility of reducing neonatal exposure to these excipients through product substitution. Data on all medication administered to hospitalized neonates from 1st of February to 1st of August 2018 along with patients` demographic data were collected from medical records for each neonate. Excipients were identified from the Summaries of Product Characteristics. Three stage criteria for product substitution were: (1) same active pharmaceutical ingredient (API) and route of administration; (2) 1 plus same dosage form; (3) 1 and 2 plus same strength. In total, 100 excipients were found in 2388 prescriptions comprising 67 medications and 60 API administered to 294 (183 preterm and 111 term) hospitalized neonates. The excipients of interest (EOI) were present in 409 (17.1%) prescriptions and were administered to 131 (71.6%) preterm and 52 (46.8%) term neonates through a relatively small number of products (n=27; 32.8%). In relation to prescription frequency, the most common EOI was polysorbate 80, found in 229 (56%) of EOI-containing prescriptions. Substitution with EOIfree products was possible for 14 (63.6%), 12 (54.5%) and 5 (22.7%) products, according to the first-, second- and third-stage criteria, respectively. We have provided the first detailed description of neonatal exposure to potentially harmful excipients among neonates admitted to a neonatal intensive care unit in Kosovo. Unnecessary exposure could be reduced by using EOI-free products available in the local medicine market. Collaborative initiative is required to build up the evidence on the use of EOI in neonates and raising awareness among health care professionals on use of products without EOI where possible.

Codeine for Acute Pain Related to Caesarean Section


 Caesarean section rates have increased over the past 3 decades. Caesarean section is often associated with acute post-operative abdominal pain and medications containing codeine have been used for pain management. There are concerns related to the use of codeine for this purpose, particularly regarding the potential for neonatal toxicity and opioid-related adverse events for the postpartum patient.
 There is limited evidence regarding the clinical effectiveness of codeine, with or without acetaminophen or nonsteroidal anti-inflammatory drugs, in patients who have undergone Caesarean section. One randomized controlled trial found that codeine in combination with paracetamol (i.e., acetaminophen) provided better pain relief compared to paracetamol only or placebo in patients with high levels of post-Caesarean section pain. However, no difference in pain relief was observed between codeine in combination with paracetamol, paracetamol only, or placebo in patients with moderate levels of post-Caesarean section pain.
 No evidence was found regarding the clinical effectiveness of codeine alone for acute pain in this specific population.

Why the Maternal Medication List Matters: Neonatal Toxicity From Combined Serotonergic Exposures

Serotonergic medications are used for the prevention and treatment of depression during pregnancy. Selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors (SNRIs) can cause poor neonatal adaptation, which has been attributed to withdrawal versus toxicity. Bupropion, a norepinephrine-dopamine reuptake inhibitor, is often used as an adjunctive agent to selective serotonin reuptake inhibitors or SNRIs for refractory depression. Quetiapine, an atypical antipsychotic, may also be used in more complex cases. When combined with serotonergic drugs, bupropion and quetiapine are associated with increased risk of serotonin syndrome in adults. We describe a neonate exposed to venlafaxine (an SNRI), bupropion, and quetiapine in utero who presented nearly immediately after birth with encephalopathy and abnormal movements. The severity and rapidity of symptoms may be attributable to potentiation of venlafaxine's serotonergic effects by bupropion and quetiapine. Neonatal providers should be aware of maternal medications and prepare for possible adverse effects, particularly from common psychotropic exposures.

Ameliorating effect of leukotriene receptor antagonist in multi-organ toxicity induced in rat offspring, a possible role for epidermal growth factor

Purpose: Nowadays, there is a dramatic increase in the interest of potential impact of consumer-relevant engineered nanoparticles on pregnancy. Materials and methods: This study investigated the possible protective effect of montelukast in neonatal organ toxicity induced by maternal exposure to silver nanoparticles (AgNPs) in rats. Results: It was noticed that montelukast reduced serum urea, creatinine, renal caspase-3 immunoreactivity and IL-1β and increased total antioxidant capacity, as compared to AgNPs. In kidney and bone tissue, montelukast reduced oxidative stress parameters and TNF-α level that was increased with AgNPs. Surprisingly, montelukast administration increased epidermal growth factor (EGF) in bone and reduced it in kidney. Furthermore, as compared to AgNPs, montelukast improved histopathological picture of kidney and bone. Conclusions: In conclusion, montelukast antagonized the biochemical and histopathological changes occurred in kidneys and bones of rat offspring by maternal exposure to AgNPs, mostly by anti-oxidant, anti-apoptotic and anti-inflammatory actions with a possible role for EGF.

Effects of the aqueous extract of Phyllanthus niruri Linn during pregnancy and lactation on neurobehavioral parameters of rats’ offspring

Ethnopharmacological relevancePhyllanthus niruri L. (Phyllanthaceae) is a plant used in traditional medicine, mainly to treat kidney stones. However, the effects of maternal exposure to P. niruri remain poorly explored. Aim of the studyThe objective of this study was to investigate the effects of administration of aqueous extract of P. niruri (AEPN) during pregnancy and lactation, in maternal toxicity, reflex maturation, and offspring memory. Materials and methodsPregnant rats were divided into three groups (n = 8/group): Control (vehicle), AEPN 75, and AEPN 150 (each respectively treated with P. niruri at a dose of 75 and 150 mg/kg/day). The animals were treated via intragastric gavage during pregnancy and lactation. Weight gain, feed intake, and reproductive performance were analyzed in the mothers. In the offspring, the following tests were performed: Neonatal Reflex Ontogeny, Open Field Habituation Test and the Object Recognition Test in adulthood. ResultsMaternal exposure to AEPN did not influence weight gain, feed intake, or reproductive parameters. In the offspring, anticipation of reflex ontogenesis (time of completion) was observed (p < 0.05). During adulthood, the AEPN groups presented decreases in exploratory activity upon their second exposure to the Open Field Habituation Test (in a dose-dependent manner) (p < 0.05). In the Object Recognition Test, administration of the extract at 75 and 150 mg/kg induced significant dose-dependent improvements in short and long-term memory (p < 0.05). ConclusionAdministration of the AEPN accelerated the reflex maturation in neonates, and improved offspring memory while inducing no maternal or neonatal toxicity.

Neuroradiologic Phenotyping of Galactosemia: From the Neonatal Form to the Chronic Stage.

Galactosemia is a rare genetic condition caused by mutation of enzymes involved in galactose and glucose metabolism. The varying clinical spectrum reflects the genetic complexity of this entity manifesting as acute neonatal toxicity syndrome, requiring prompt diagnosis and treatment, to more insidious clinical scenarios as observed in the subacute and chronic presentations. The current literature predominantly focuses on the long-standing sequelae of this disease. The purpose of this multicenter clinical report comprising 17 patients with galactosemia is to highlight the MR imaging patterns encompassing the whole spectrum of galactosemia, emphasizing the 3 main clinical subtypes: 1) acute neonatal presentation, with predominant white matter edema; 2) subacute clinical onset with a new finding called the "double cap sign"; and 3) a chronic phase of the disease with heterogeneous imaging findings. The knowledge of these different patterns together with MR spectroscopy and the clinical presentation may help in prioritizing galactosemia over other neonatal metabolic diseases and prevent possible complications.

Acute Phenobarbital Poisoning for the Management of Seizures in Newborns and Children; A Systematic Literature Review.

While phenobarbital (PB) is commonly used for the management of seizures in newborns and pediatrics, its administration may accompany acute poisoning. We aimed to review the literature to find out the frequency of PB poisonings in newborns and children with seizures. A literature search was performed by two independent reviewers to find relevant articles about PB toxicity in neonates and pediatrics that were treated for the seizure. 18 articles met the inclusion criteria and were included in this systematic review. The main reasons for PB poisoning in studied patients were therapeutic intoxication. Reported signs of PB poisoning were lethargy, sedation, lack of sucking, fever, skin rash, hepatic inflammation and alopecia. Moreover, respiratory depression, encephalopathy, myocardial failure, syndrome of inappropriate antidiuretic hormone, and coma were among the complications of acute PB toxicity in children and infants. PB therapy for the management of seizures in newborns and children might be associated with poisoning. Although supportive and symptomatic treatments are available for PB overdose, it should be administered with caution, using drug monitoring to avoid toxicity.

Use of Prescribed Psychotropics during Pregnancy: A Systematic Review of Pregnancy, Neonatal, and Childhood Outcomes.

This paper reviews the findings from preclinical animal and human clinical research investigating maternal/fetal, neonatal, and child neurodevelopmental outcomes following prenatal exposure to psychotropic drugs. Evidence for the risks associated with prenatal exposure was examined, including teratogenicity, neurodevelopmental effects, neonatal toxicity, and long-term neurobehavioral consequences (i.e., behavioral teratogenicity). We conducted a comprehensive review of the recent results and conclusions of original research and reviews, respectively, which have investigated the short- and long-term impact of drugs commonly prescribed to pregnant women for psychological disorders, including mood, anxiety, and sleep disorders. Because mental illness in the mother is not a benign event, and may itself pose significant risks to both mother and child, simply discontinuing or avoiding medication use during pregnancy may not be possible. Therefore, prenatal exposure to psychotropic drugs is a major public health concern. Decisions regarding drug choice, dose, and duration should be made carefully, by balancing severity, chronicity, and co-morbidity of the mental illness, disorder, or condition against the potential risk for adverse outcomes due to drug exposure. Globally, maternal mental health problems are considered as a major public health challenge, which requires a stronger focus on mental health services that will benefit both mother and child. More preclinical and clinical research is needed in order to make well-informed decisions, understanding the risks associated with the use of psychotropic medications during pregnancy.

Exploring the transversus abdominis plane block in cesarean sections and the subsequent toxicity risk to neonates via breast milk.

The transversus abdominis plane (TAP) block with its wide application has shown to be an analgesic effective for use in abdominal surgeries, including for cesarean section. However, the bupivacaine delivered in the TAP block comes with the risk of toxicity, both central nerve system (CNS) and cardiovascular system, and has been shown in some instances to reach maximum serum concentrations in excess of the 2 μg/mL associated with the lower end of CNS toxicity. There is a specific concern with cesarean section TAP blocks of the anesthetic passage to the neonate via maternal breast milk and whether this poses a toxicity risk. Bupivacaine has been shown to pass into maternal milk at concentrations 0.34 times the maternal serum concentration. Preliminary statistical analyses suggest that the bupivacaine delivered in breast milk is not in concentrations high enough to cause neonatal toxicity, but further studies would be useful in identifying what the toxicity risk is, if any, to the neonates' breastfeeding after the delivery and TAP block.

Chronic Auditory Toxicity in Late Preterm and Term Infants With Significant Hyperbilirubinemia.

Significant hyperbilirubinemia (SHB) may cause chronic auditory toxicity (auditory neuropathy spectrum disorder and/or sensorineural hearing loss); however, total serum bilirubin (TSB) does not discriminate neonates at risk for auditory toxicity. Our objective was to compare TSB, bilirubin albumin molar ratio (BAMR), and unbound bilirubin (UB) for their association with chronic auditory toxicity in neonates with SHB (TSB ≥20 mg/dL or TSB that met criteria for exchange transfusion). Infants ≥34 weeks' gestational age (GA) with SHB during the first 2 postnatal weeks were eligible for a prospective longitudinal study in India. Comprehensive auditory evaluations were performed at 2 to 3 months of age by using auditory brainstem response, tympanometry, and an otoacoustic emission test and at 9 to 12 months of age by using audiometry. The evaluations were performed by an audiologist unaware of the degree of jaundice. A total of 93 out of 100 infants (mean GA of 37.4 weeks; 55 boys, 38 girls) who were enrolled with SHB were evaluated for auditory toxicity. Of those, 12 infants (13%) had auditory toxicity. On regression analysis controlling for covariates, peak UB (but not peak TSB or peak BAMR), was associated with auditory toxicity (odds ratio 2.41; 95% confidence interval: 1.43-4.07; P = .001). There was significant difference in the area under the receiver operating characteristic curves between UB (0.866), TSB (0.775), and BAMR (0.724) for auditory toxicity (P = .03) after controlling for covariates. Unconjugated hyperbilirubinemia indexed by UB (but not TSB or BAMR) is associated with chronic auditory toxicity in infants ≥34 weeks' GA with SHB.

Dosing antibiotics in neonates: review of the pharmacokinetic data.

Antibiotics are often used in neonates despite the absence of relevant dosing information in drug labels. For neonatal dosing, clinicians must extrapolate data from studies for adults and older children, who have strikingly different physiologies. As a result, dosing extrapolation can lead to increased toxicity or efficacy failures in neonates. Driven by these differences and recent legislation mandating the study of drugs in children and neonates, an increasing number of pharmacokinetic studies of antibiotics are being performed in neonates. These studies have led to new dosing recommendations with particular consideration for neonate body size and maturation. Herein, we highlight the available pharmacokinetic data for commonly used systemic antibiotics in neonates.

Classical galactosemia in a Thai infant: case report and review of the literature

Abstract Background Classic galactosemia is an inherited disorder of galactose metabolism that is caused by a deficiency of galactose-1-phosphate uridyl transferase (GALT). As in other Asians, the prevalence of galactosemia in Thai people is very low. An accumulation of its toxic metabolites leads to acute neonatal toxicity and long-term complications. Objective To present the fourth known published case of classical galactosemia in a Thai infant and review the English language literature. Method A 4-month-old boy who was born into a Thai family with no history of consanguinity developed persistent jaundice, hepatosplenomegaly, and lethargy, since introduction to breast-feeding. Result Urine gas chromatography-mass spectrometry demonstrated a high level of galactose, galactitol, and galactonate. Liver biopsy confirmed severe hepatocellular damage and fibrosis. Breast-feeding was immediately replaced by a lactose-free diet and soy milk. His clinical features and subsequent laboratory measurements improved. Developmental delays and defects on speech presented at the last followed up. Conclusion Long-term complications are diet-independent and inevitable. However early recognition and immediate withdraw of galactose from the diet can prevent serious morbidity and mortality.

Maternal Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes Syndrome and Neonatal Magnesium Toxicity: A Case Report

Introduction: Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is a progressive disorder associated with neurologic, cardiac, neuromuscular, hepatic, metabolic and gastrointestinal dysfunction, including potential anesthetic and obstetrical complications. Increased susceptibility to drugs in patient with MELAS syndrome can be due to drug-induced mitochondrial toxicity and/or decreased elimination. We present here a case of severe neonatal magnesium sulfate toxicity in the context of MELAS syndrome. Case presentation: A 43-year-old, gravida 5, para-5 (4 prior vaginal deliveries and the current cesarean section) woman with asymptomatic MELAS syndrome (carrier of the genetic variant NC_012920.1: m3243A>G in 20% of the mitochondrial DNA) was given intravenous magnesium sulfate for preeclampsia shortly before an emergency cesarean section at 33 weeks. The newborn presented a severe toxic effect characterized by cardio-respiratory arrest. Genetic evaluation revealed that he carried the same maternal mutation, but at a higher rate (80%). There was no other risk factor for cardio-respiratory arrest other than the potential interaction between the maternal/ neonatal mitochondrial disease and the medication, thus potentially leading to the risk of overdose. Conclusion: The cause of the severe toxicity is uncertain, but it may have resulted from magnesium accumulation in the mother and/or the newborn due the presence of the MELAS syndrome in the neonate. A close assessment of potential severe drug toxicity in mothers and neonates with MELAS syndrome is warranted.

Auditory toxicity in late preterm and term neonates with severe jaundice.

Jaundice may cause auditory toxicity (auditory neuropathy and hearing loss). However, total serum bilirubin (TSB) does not discriminate neonates at risk for auditory toxicity. We compared TSB, bilirubin:albumin molar ratio (BAMR), and unbound bilirubin for their association with auditory toxicity in neonates with severe jaundice (TSB ≥342μmol/L, or that met exchange transfusion). Neonates greater or equal to 34 weeks gestational age with severe jaundice during the first 2 postnatal weeks were eligible for prospective cohort study, unless they had craniofacial malformations, chromosomal disorders, toxoplasmosis, other infections, rubella, cytomegalovirus, herpes simplex infections, surgery, or family history of congenital deafness. Twenty-eight out of 100 neonates (mean gestational age 37.4wks; 59 males, 41 females) had auditory toxicity. Peak unbound bilirubin, but not peak TSB and BAMR, was associated with auditory toxicity (p<0.05) in neonates with severe (TSB <427.5μmol/L) and extreme hyperbilirubinemia (TSB ≥427.5μmol/L). Area under the receiver operating characteristic curve for unbound bilirubin (0.78) was significantly greater (p=0.03) than TSB (0.54) among neonates with severe but not extreme hyperbilirubinemia. Unbound bilirubin is more strongly associated with auditory toxicity than TSB and/or BAMR in greater or equal to 34 weeks gestational age neonates with severe jaundice. Unbound bilirubin is a better predictor than TSB in neonates with severe hyperbilirubinemia.