Propylene Glycol Toxicity in a Pediatric Patient: The Dangers of Diluents

Abstract

This report will present a case of neonatal propylene glycol poisoning from the use of intravenous lorazepam and also discuss the toxicity of diluents in general. Although used as a diluent in many pharmaceuticals and generally considered safe, propylene glycol can cause serious side effects: hyperosmolality in burn victims due to silver sulfadiazine products containing propylene glycol and in premature babies due to particular multivitamin preparations, irreversible perception deafness, skin irritation, high anion gap acidosis due to elevated lactate levels, and reversible neurological disturbances. Toxicity caused by propylene glycol may be manifested by hyperosmolality, lactic acidosis, hemolysis and hemoglobinuria, skin irritation, deafness, and other neurological disturbances.¹ Historically, the toxicity of diluents played an important role in the development of toxicity testing before the release of new drugs. The topic is current, as evidenced by the Important Drug Warning letter recently issued by Glaxo Wellcome, the manufacturer of Agenerase, warning about the toxicities and drug interactions associated with the propylene glycol diluent in the oral solution, as well as by competitive interference with the aldehyde dehydrogenase enzyme pathway. This report and discussion is included in the Forensic Pharmacist issue because the case investigation arose out of retention of one of the authors (O'Donnell) as an expert witness and consultant on behalf of the child/subject of the case report.