Adverse drug reactions in neonates

Ethical Considerations in Neonatal Research

Children are considered a vulnerable population and have traditionally been excluded from research studies. This exclusion of children in general, and neonates in particular, from clinical research hampers the development of safe and effective therapies in this population. However, research involving children (including infants) is essential to guide therapy and optimize care. Neonatal research is complex, time intensive, difficult and expensive to conduct, and raises some unique ethical considerations. The complexity of research in this population is highlighted by the fear of causing harm to fragile sick infants which has led to the creation of special regulations on the degree of risk exposure permissible in research involving infants. This is further compounded by the inability of infants to provide informed consent or assent and the reliance on obtaining surrogate consent from parents who may themselves be vulnerable and overwhelmed by their infant's illness and the amount of information provided to them. In this review, we discuss the evolution of ethical regulations related to research, the justification for research in infants, and some of the ethical nuances of research in this population.

Toward precision medicine in pediatric population using cytochrome P450 phenotyping approaches and physiologically based pharmacokinetic modeling

The activity of drug-metabolizing enzymes (DME) shows high inter- and intra-individual variability. Genetic polymorphisms, exposure to drugs, and environmental toxins are known to significantly alter DME expression. In addition, the activity of these enzymes is highly age-dependent due to maturation processes that occur during development. Currently, there is a vast choice of phenotyping methods in adults using exogenous probes to characterize the activity of these enzymes. However, this can hardly be applied to children since it requires the intake of non-therapeutic xenobiotics. In addition, sampling may be challenging in the pediatric population for a variety of reasons: limited volume (e.g., blood), inappropriate sampling methods for age (e.g., urine), and metric requiring invasive or multiple blood samples. This review covers the main existing methods that can be used in the pediatric population to determine DME activity, with a particular focus on cytochrome P450 enzymes. Less invasive tools are described, including phenotyping using endogenous probes. Finally, the potential of pediatric model-informed precision dosing using physiologically based pharmacokinetic modeling is discussed.

Informed consent for neonatal trials: practical points to consider and a check list

Obtaining informed consent from parents of critically ill neonates can be challenging. The parental decision-making process is influenced by the severity of the child's condition, the benefit-risk balance, their emotional state and the quality of the relationship with the clinical team. Independent of local legislation, parents may prefer that consent is sought from both. Misconceptions about the absence of risks or unrealistic expectations about benefits should be openly addressed to avoid misunderstandings which may harm the relationship with the clinical team. Continuous consent can be sought where it is unclear whether the free choice of parental consent has been compromised. Obtaining informed consent is a dynamic process building on trusting relationships. It should include open and honest discussions about benefits and risks. Investigators may benefit from training in effective communication. Finally, involving parents in neonatal research including the development of the informed consent form and the process of obtaining consent should be considered standard practice.

Reported Adverse Drug Reactions in Infants: A Nationwide Analysis in Malaysia

Spontaneous adverse drug reactions (ADRs) reporting is a useful source of drug safety information in infants as only adult patients are routinely tested in clinical trials. This study was aimed to evaluate the spontaneously reported ADRs using WHO Adverse Reaction Terminology and to identify the common drugs associated with ADRs in children under 2 years of age. A retrospective analysis of ADR data for children below 2 years old from 2000 to 2013 was conducted using the data extracted from Malaysia’s national pharmacovigilance database, QUEST2 System. From 2000 to 2013, Malaysia’s National Pharmaceutical Control Bureau received a total of 11,932 reports for children from various healthcare facilities in Malaysia. 14.0% (n = 1667) of the ADRs reported for those children were related to children under 2 years old. The data retrieved was analyzed in terms of age, gender, source of reporting, type of reporters, suspected medicines and characteristics of ADRs (category, onset, severity, and outcomes). A total of 1312 ADRs reported in 907 ADR reports were analyzed. The most common ADRs reported were skin appendage disorders (60.1%), and the most frequently reported symptoms were rash (n = 215), maculopapular rash (n = 206), urticaria (n = 169), erythematous rash (n = 76), and pruritus (n = 58). In general, drugs from antibacterials for systemic use (58.8%) appeared to be the most common contributors to ADRs in children below 2 years old. Penicillins and other β-Lactam Antibacterials accounted for more than 40% of all drugs implicated in ADRs. The majority of ADRs were subacute reactions that occurred within 24 h of exposure to the drug. A high proportion of ADRs was classified as mild, and most victims had no sequela. Only one fatality was seen. There were 10 cases for each symptom, namely erythema multiforme and Stevens–Johnson Syndrome, observed in this study. A large proportion of ADRs in children under 2 years old were mainly caused by drugs from antibacterial for systemic use, with most of the ADRs manifesting in skin reactions. This study also reveals rare cutaneous ADRs experienced by Malaysian children under the age of 2, which constitutes a crucial cause of harm among children.

Clinical trials of medicines in neonates: the influence of ethical and practical issues on design and conduct

In the past, there has been a perception that ethical and practical problems limit the opportunities for research in neonates. This perception is no longer appropriate. It is now clear that research about the medicines used in neonates is an ethical requirement. It is possible to conduct high quality research in neonates if the research team adapt to the characteristics of this population. Good practice involves respecting the specific needs of newborn babies and their families by adopting relevant approaches to study design, recruitment, pharmacokinetic studies and safety assessment. Neonatal units have a unique culture that requires careful development in a research setting. Clinical investigators need to recognize the clinical and ethical imperative to conduct rigorous research. Industry needs to engage with neonatal networks early in the process of drug development, preferably before contacting regulatory agencies. Follow-up over 3-5 years is essential for the evaluation of medicines in neonates and explicit funding for this is required for the assessment of the benefit and risk of treatments given to sick newborn babies. The views of parents must be central to the development of studies and the research agenda. Ethical and practical problems are no longer barriers to research in neonates. The current challenges are to disseminate good practice and maximize capacity in order to meet the need for research among newborn babies.

Antibiotics and Antifungals in Neonatal Intensive Care Units: A Review

The incidence of infections is higher in the neonatal period than at any time of life. The basic treatment of infants with infection has not changed substantially over the last years. Antibiotics (with or without supportive care) are one of the most valuable resources in managing sick newborn babies. Early-onset (ascending or transplacental) or late-onset (hospital acquired) infections present different chronology, epidemiology, physiology and outcome. Some classes of antibiotics are frequently used in the neonatal period: penicillins, cephalosporins, aminoglycosides, glycopeptides, monobactams, carbapenems. Other classes of antibiotics (chloramphenicol, cotrimoxazole, macrolides, clindamycin, rifampicin and metronidazole) are rarely used. Due to emergence of resistant bacterial strains in Neonatal Intensive Care Units (NICU), other classes of antibiotics such as quinolones and linezolid will probably increase their therapeutic role in the future. Although new formulations have been developed for treatment of fungal infections in infants, amphotericin B remains first-line treatment for systemic Candida infection. Prophylactic antibiotic therapy is almost always undesirable. Challenges from pathogens and antibiotic resistance in the NICU may warrant modification of traditional antibiotic regimens. Knowledge of local flora and practical application of different antibiotic characteristics are key to an effective and safe utilization of antibiotics and antifungals in critical newborns admitted to the NICU, and especially in very low birth weight infants.

Patterns of Drug Utilization in a Neonatal Intensive Care Unit

The objective of this study was to determine drug use in newborns at an inborn tertiary care neonatal intensive care unit, serving a predominantly African American population, to identify educational/research priorities in neonatal drug therapy. Data on demographics and exposure rates to all drugs from 6839 neonates born between January 1997 and June 2004 were analyzed. Number of drugs used was correlated with race, gender, gestational age, birthweight, and survival status. The contribution of these factors to mean drug use was predicted by multivariate regression analysis. In this population of 80% African Americans, mean drug use was 3.6/infant, with the highest use in the 24- to 27-week gestational age group (11.7/infant). Ampicillin and cefotaxime had the highest exposure rates. Premature infants had high use of surfactant, pressor agents, and diuretics. Caucasians, males, gestational age<28 weeks, and birthweight<1000 g were the risk factors for higher drug exposure. Future research/education must emphasize these therapeutic areas with priority assigned to low-birthweight infants.

An algorithm to detect adverse drug reactions in the neonatal intensive care unit

Critically ill newborns in neonatal intensive care units (NICUs) are at greater risk of developing adverse drug reactions (ADRs). Differentiation of ADRs from reactions associated with organ dysfunction/immaturity is difficult. Current ADR algorithm scoring was established arbitrarily without validation in infants. The study objective was to develop a valid and reliable algorithm to identify ADRs in the NICU. Algorithm development began with a 24-item questionnaire for data collection on 100 previously suspected ADRs. Five pediatric pharmacologists independently rated cases as definite, probable, possible, and unlikely ADRs. Consensus "gold standard" was reached via teleconference. Logistic regression and iterative C programs were used to derive the scoring system. For validation, 50 prospectively collected ADR cases were assessed by 3 clinicians using the new algorithm and the Naranjo algorithm. Weighted kappa and intraclass correlation coefficient (ICC) were used to compare validity and reliability of algorithms. The new algorithm consists of 13 items. Kappa and ICC of the new algorithm were 0.76 and 0.62 versus 0.31 and 0.43 for the Naranjo algorithm. The new algorithm developed using actual patient data is more valid and reliable than the Naranjo algorithm for identifying ADRs in the NICU population. Because of the relatively small and nonrandom samples, further refinement and additional testing are needed.

General medications utilization and cost patterns in hospitalized children

Drug utilization in the in-patient setting can provide mechanisms to assess drug prescribing trends, efficiency and cost-effectiveness of hospital formularies and examine sub-populations such as children for which prescribing habits are different from adults.

Clinical trials of drugs used off-label in neonates: ethical issues and alternative study designs

The use of drugs for indications unapproved by the Food and Drug Administration (FDA), often called "off label use, "is widespread in children, including neonates. The widespread off-label use of drugs in neonates presents ethical and safety challenges. Since the passage of the Best Pharmaceuticals for Children Act (BPCA) in 2002, both the FDA and National Institutes of Health (NIH) have taken initiatives to facilitate and encourage research to achieve the necessary labeling for drugs routinely used in infants and children. Federal regulations provide broad rules and guidance for the protection of human subjects in research. However, there are ethical issues that a physician may face when designing clinical trials of drugs in neonates that are routinely used off-label and widely believed to be beneficial. We attempt to describe these ethical challenges and provide recommendations, including alternative study designs, to resolve them in an ethical framework that takes into account the Belmont Report, the statement of the World Medical Association (WMA), and federal regulations.

Antibiotics in neonatal infections: a review

The bacteria most commonly responsible for early-onset (materno-fetal) infections in neonates are group B streptococci, enterococci, Enterobacteriaceae and Listeria monocytogenes. Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are the main pathogens in late-onset (nosocomial) infections, especially in high-risk patients such as those with very low birthweight, umbilical or central venous catheters or undergoing prolonged ventilation. The primary objective of the paediatrician is to identity all potential cases of bacterial disease quickly and begin antibacterial treatment immediately after the appropriate cultures have been obtained. Combination therapy is recommended for initial empirical treatment in the neonate. In early-onset infections, an effective first-line empirical therapy is ampicillin plus an aminoglycoside (duration of treatment 10 days). An alternative is ampicillin plus a third-generation cephalosporin such as cefotaxime, a combination particularly useful in neonatal meningitis (mean duration of treatment 14 to 21 days), in patients at risk of nephrotoxicity and/or when therapeutic monitoring of aminoglycosides is not possible. Another potential substitute for the aminoglycoside is aztreonam. Triple combination therapy (such as amoxicillin plus cefotaxime and an aminoglycoside) could also be used for the first 2 to 3 days of life, followed by dual therapy after the microbiological results. In late-onset infections the combination oxacillin plus an aminoglycoside is widely recommended. However, vancomycin plus ceftazidime (+/- an aminoglycoside for the first 2 to 3 days) may be a better choice. Teicoplanin may be a substitute for vancomycin. However, the initial approach should always be modified by knowledge of the local bacterial epidemiology. After the microbiological results, treatment should be switched to narrower spectrum agents if a specific organism has been identified, and should be discontinued if cultures are negative and the neonate is in good clinical condition. Penicillins and third-generation cephalosporins are generally well tolerated in neonates. There is controversy regarding whether therapeutic drug monitoring of aminoglycosides will decrease toxicity (particularly renal damage) in neonates, and on the efficacy and safety of a single daily dose versus multiple daily doses of these drugs. Toxic effects caused by vancomycin are uncommon, but debate still exists over the need for therapeutic drug monitoring of this agent. When antibacterials are used in neonates, accurate determination of dosage is required, particularly for compounds with a low therapeutic index and in patients with renal failure. Very low birthweight infants are also particularly prone to antibacterial-induced toxicity.