Comparison of Two Morphine Dosing Strategies in the Management of Neonatal Abstinence Syndrome

The incidence of neonatal abstinence syndrome (NAS) has increased in recent years. Treatment approaches usually involve opioid replacement; however, the optimal treatment strategy is unknown. This study sought to determine the impact of weight- and symptom-based morphine dosing strategies on LOS and medication exposure in patients with NAS.

A retrospective review was conducted from May 2015 to June 2017 at 2 NICUs within a health-system using different dosing approaches for NAS. Data were compared using Fisher exact tests for categorical data and t tests and Wilcoxon ranked sums for continuous data.

Baseline demographics were well-matched except for postmenstrual age at morphine initiation (p = 0.04). The weight-based group had a larger initial morphine dose (p < 0.001) and fewer number of steps to maximum morphine dose (p = 0.009). There were no differences between groups in LOS, number of dose adjustments, doses administered, weaning steps, maximum dose, or need to re-escalate dosing. There was also no difference between the first 3 modified Finnegan scores (MFS) after transferring patients to a neonatology service. Neonates with symptom-based dosing had a higher maximum MFS (p = 0.024). Neonates in the symptom-based group required adjunct therapy more often (p < 0.0001).

Data indicate the dosing strategy impacts number of steps to reach maximum dose and need for adjunctive therapy. Weight-based dosing may decrease the number of steps required to reach the morphine maximum dose and the need for adjunctive therapy by controlling NAS symptoms earlier.