Hyperosmolality related to propylene glycol in an infant

Excipient exposure in very low birth weight preterm neonates

OBJECTIVE

The excipients benzyl alcohol, propylene glycol and ethanol are present in medications used in the neonatal intensive care unit. Exposure to high levels can have adverse effects in a neonatal population. The objective was to quantify excipient exposure in very low birth weight (VLBW) neonates and identify risk factors associated with greater exposure.

STUDY DESIGN

A retrospective record review of VLBW infants admitted over 1 year. Excipient exposures were calculated and multivariable regression analyses identified risk factors for increasing exposure.

RESULTS

In total, 98% of subjects were exposed to at least one excipient. A total of 5 to 9% received doses higher than recommended for adults. Necrotizing enterocolitis, seizure, bronchopulmonary dysplasia and longer stay predicted higher excipient exposure.

CONCLUSION

The excipients examined are in medications commonly prescribed for VLBW neonates, and cumulative doses may exceed recommended exposures for adults. Although safety profiles have not been established, judicious use of medication containing these excipients is warranted for this population.

Newborns and drug studies: the NICHD/FDA newborn drug development initiative

BACKGROUND

Progress has been made in research on the effects of drug therapy on pediatric patients, but neonates are still an understudied population. Those most likely to receive drug therapy (eg, preterm infants) are least likely to be studied.

OBJECTIVES

The purposes of this article are to summarize an initiative developed jointly by the National Institute of Child Health and Human Development (NICHD) and the US Food and Drug Administration (FDA) and to introduce a series of articles developed as a result of this initiative.

METHODS

Information for this article was gathered from the proceedings of a workshop cosponsored by the NICHD and the FDA that took place March 29 and 30, 2004, in Rockville, Maryland.

RESULTS

: Dosing based on use in adults and older children has resulted in adverse events among newborn infants, and may have long-term effects. Moreover, formulations appropriate for use in neonates are often unavailable, and compensatory efforts such as mixing crushed tablets into formula may interfere with accurate dose delivery. Under the Best Pharmaceuticals for Children Act of 2002, government agencies work with experts in pediatrics and pediatric research to develop and prioritize a list of off-patent drugs for which pediatric studies are urgently needed. Four such listings were published in the Federal Register from January 2003 through January 2005. The NICHD and FDA have also initiated the Newborn Drug Development Initiative (NDDI), a multiphase program to determine gaps in knowledge concerning neonatal pharmacology and clinical trial design and to explore novel study designs for use in newborns, with the ultimate goal of increasing our knowledge about the safety and efficacy of drugs used to treat newborns.

CONCLUSIONS

Most drugs used to treat newborns still lack appropriate dosing, efficacy, and safety studies in this vulnerable population. The NICHD and FDA developed the NDDI as an ongoing process to identify and suggest strategies for addressing obstacles to conducting drug trials in the newborn.

Osmolality of solutions, emulsions and drugs that may have a high osmolality: aspects of their use in neonatal care

OBJECTIVE

Administration of some hypertonic substances to neonates has been associated with a variety of adverse effects. This study was conducted to determine the osmolality of intravenous drugs and solutions used in neonates receiving intensive care.

METHODS

Osmolality was measured by freezing point depression. Vasoactive drugs, diuretics, anticonvulsants, antimicrobials, and glucose and electrolyte solutions were some of the substances analyzed.

RESULTS

The osmolalities of 90 substances were measured; the respective intra-assay and interassay coefficients of variation were always less than 5%. A few drugs were found to be extremely hypertonic (> 8000 mOsm/kg), and most of them contain propylene glycol as vehicle (e.g. digoxin, phenytoin, diazepam and phenobarbital). Other drugs, at the same concentration, evidenced a significant discrepancy of osmolality depending on the trademark.

CONCLUSIONS

The finding of some extremely hypertonic drugs highlights the need for further investigation in order to study their potential adverse effects in neonates, as well as to evaluate any advantage in diluting, infusing slowly or even avoiding such substances. Given the fact that there exists a discrepancy in osmolalities in some drugs at the same concentration depending on the trademark, the more isotonic solutions should be the preferred choice for intravenous administration.

Propylene glycol-induced proximal renal tubular cell injury

Propylene glycol is a solvent that is used in many oral, injectable, and topical medications. Although uncommon, acute renal failure has been attributed to propylene glycol. The mechanism of propylene glycol-mediated renal injury is unknown. We report a case of acute renal failure in a 16-year-old boy given large doses of pentobarbital and phenobarbital, both of which are solubilized with propylene glycol. A renal biopsy showed proximal renal tubular cell swelling and vacuole formation. The data from this case suggest that the reversible acute renal failure caused by propylene glycol is attributable to proximal renal tubular cell injury.