Use of insulin glargine in the management of neonatal hyperglycemia in an ELBW infant

Abstract

Neonatal hyperglycemia is common in extremely low birth weight (ELBW) infants because of physiologic stress, exogenous glucose infusion, and postnatal corticosteroid therapy for hypotension, adrenal insufficiency, and pulmonary immaturity. The use of long-acting insulin glargine has been described in the treatment of transient neonatal diabetes in the premature infant, but in these reports is a lack of regard to its use in the treatment of iatrogenic neonatal hyperglycemia. We present the case of an ELBW infant with significant hyperglycemia that was refractory to usual treatment but demonstrated a favorable response to long-acting subcutaneous insulin glargine. The pharmacokinetics on regular insulin and long-acting insulin are different. Regular insulin is broken down into biologically active monomers after subcutaneous injection, and long-acting insulin forms microprecipitates and is gradually released to the body at a neutral physiologic pH after subcutaneous injection. Pharmacokinetics of both regular insulin and long-acting insulin are not clear in ELBW infants. However, with further research on long-acting insulin, it can be used safely to achieve consistent euglycemia with once-daily administration in neonatal hyperglycemia.