Neonatal Therapeutics: Considerations for Dosing

Acyclovir Dosing Practices Across a Multicenter Cohort of Neonatal Intensive Care Units

BACKGROUND

Acyclovir is the first-line therapy for neonatal herpes simplex virus infections. Therapy can mitigate morbidity and mortality but carries a risk for toxicity. We aimed to compare acyclovir dosing in neonatal intensive care units to published recommendations based on population pharmacokinetic (PopPK) analysis.

METHODS

We performed a multicenter cohort study of infants in neonatal intensive care units managed by the Pediatrix Medical Group from 1997 to 2020. We included all infants who received acyclovir with complete dosing information. Our primary outcome was the proportion of courses with dosing within 80%-120% of the PopPK recommended daily dose and at the recommended dosing frequency. We compared dosing before and after the publication of the 2014 PopPK recommendations using linear probability modeling.

RESULTS

We identified 6862 infants with complete dosing information across 308 centers. Dosing met PopPK recommendations for 41% of treatment courses for infants <30 weeks postmenstrual age (PMA), 71% for infants 30 to <36 weeks PMA and <1% for infants ≥ 36 weeks PMA. Comparison of dosing from 1997 to 2013 with that from 2015 to 2020 showed a significant increase in dosing meeting PopPK recommendations for infants <30 weeks PMA (P = 0.008) and infants 30 to <36 weeks PMA (P = 0.02) but not infants ≥ 36 weeks PMA (P = 0.29). No significant increase in dosing meeting PopPK recommendations was seen for any PMA group when comparison was limited to more recent years (2008-2013 vs. 2015-2020).

CONCLUSIONS

Dosing meeting PopPK recommendations increased over time for some PMA groups, but dosing different than PopPK recommendations remains common. More research is needed to clarify optimal dosing strategies in these infants.

Sertraline, citalopram and paroxetine in lactation: passage into breastmilk and infant exposure

Objectives

This study aimed to investigate the plasma and breastmilk concentrations for sertraline, citalopram and paroxetine for assessment of the Milk/Plasma (M/P) ratio and Absolute Infant Dose (AID), and to determine actual infant drug exposure through breastfeeding. Subsequently, informed recommendations will be formulated regarding the advisability of breastfeeding in women undergoing treatment with the three most widely used antidepressants.

Methods

A pharmacokinetic study in lactating women and their infants using sertraline, citalopram or paroxetine was performed. Paired breastmilk and plasma samples and single point infant plasma samples were collected to determine antidepressant concentrations. An Area Under the Curve (AUC) based approach with the trapezoidal rule was used to calculate M/P ratios and AID for all three antidepressants by combining all measured concentrations for the same dose.

Results

Thirty-seven lactating women and their infants participated in this study. 111 paired breastmilk and plasma samples and 37 single point infant plasma samples were collected. Detectable concentrations of sertraline, citalopram and paroxetine were present in all breastmilk samples. For sertraline and citalopram M/P ratio is above one, indicating higher breastmilk than plasma concentrations, however, drug exposure by breastmilk did not lead to detectable plasma drug levels in any of the 15 infants for sertraline, for nine (out of 13) infants for citalopram and for eight (out of nine) infants for paroxetine.

Conclusion

Given the well-known benefits of breastfeeding, our findings support breastfeeding of infants by mothers who are taking sertraline, citalopram or paroxetine is safe. Sertraline and paroxetine are the preferred antidepressants during breastfeeding, reaching mostly undetectable infant drug levels.

Aminoglycoside- and glycopeptide-induced ototoxicity in children: a systematic review

Background

Ototoxicity has been reported after administration of aminoglycosides and glycopeptides.

Objectives

To identify available evidence for the occurrence and determinants of aminoglycoside- and glycopeptide-related ototoxicity in children.

Materials and methods

Systematic electronic literature searches that combined ototoxicity (hearing loss, tinnitus and/or vertigo) with intravenous aminoglycoside and/or glycopeptide administration in children were performed in PubMed, EMBASE and Cochrane Library databases. Studies with sample sizes of ≥50 children were included. The QUIPS tool and Cochrane criteria were used to assess the quality and risk of bias of included studies.

Results

Twenty-nine aminoglycoside-ototoxicity studies met the selection criteria (including 7 randomized controlled trials). Overall study quality was medium/low. The frequency of hearing loss within these studies ranged from 0%–57%, whereas the frequency of tinnitus and vertigo ranged between 0%–53% and 0%–79%, respectively. Two studies met the criteria on glycopeptide-induced ototoxicity and reported hearing loss frequencies of 54% and 55%. Hearing loss frequencies were higher in gentamicin-treated children compared to those treated with other aminoglycosides. In available studies aminoglycosides had most often been administered concomitantly with platinum agents, diuretics and other co-medication.

Conclusions

In children the reported occurrence of aminoglycoside/glycopeptide ototoxicity highly varies and seems to depend on the diagnosis, aminoglycoside subtype and use of co-administered medication. More research is needed to investigate the prevalence and determinants of aminoglycoside/glycopeptide ototoxicity. Our results indicate that age-dependent audiological examination may be considered for children frequently treated with aminoglycosides/glycopeptides especially if combined with other ototoxic medication.

Challenges in clinical trials for children and young people

There is a well-known knowledge gap regarding the efficacy and safety of medicines in children of all ages and children are often treated with medicines off-label. Children are thus deprived of treatment based on the same quality of information that guides treatment in adults. The knowledge gap regarding efficacy and safety of medicines in children has been acknowledged by authorities and is reflected in legislation both in North America and in the European Union. Recent reports on the effects of legislation indicates that paediatric clinical trials remain a challenge.Paediatric clinical trials are needed in the entire developmental age spectrum and are especially needed in certain therapy areas. Paediatric clinical trials have special features compared with trials in adults, and these need to be taken into account. These special features include scientific issues related to small samples and heterogeneity, the consent/assent procedure, the need for age-appropriate study information, specific outcomes and safety issues related to development and maturation. Competence in paediatric clinical trials is required in both designing, planning, co-ordinating and organising paediatric clinical trials, as well as research infrastructure and networks to increase power and disseminate information and expert advice. Strengthening of paediatric clinical research is essential to facilitate generating the data that will let children enjoy new medical advances in a similar manner as adults.