Objective: To evaluate the effectiveness of methadone for the treatment of neonatal abstinence syndrome when used according to a preexisting clinical pathway.
Design: This is a 3-year retrospective study conducted at a single institution. In this study, neonates who received methadone for the treatment of neonatal abstinence syndrome according to a predefined clinical treatment pathway were evaluated for treatment success: defined as adherence to the methadone regimen with no residual signs of withdrawal. Data were collected for methadone dosages, Lipsitz scores, length of methadone treatment, total length of hospital stay, and relevant clinical data.
Setting: Level III neonatal ICU.
Patients: Newborn infants with in utero exposure to substances of abuse.
Interventions: None.
Measurements and main results: Sixty patients were included. The mean gestational age and birth weight were 37.07 ± 3.05 weeks and 2.77 ± 0.6 kg. All 60 patients exhibited neonatal abstinence syndrome within first 72 hours of life. Fifty-seven of 60 patients (95%) initiated methadone treatment according to protocol. There was deviation from the protocol at 48 and 72 hours of treatment with approximately 59% and 13% of the patients still on methadone at more than the prescribed amount to control neonatal abstinence syndrome. The mean ± SD total methadone exposure was 1.99 ± 1.63 mg/kg, length of treatment 11.66 ± 9.02 days, and total hospital length of stay 22.43 ± 29.3 days, suggesting significant variability in response. No significant correlation was found between birth weight or gestational age and length of treatment.
Conclusion: Clinical pathway for treating neonatal abstinence syndrome was closely followed at the initial diagnosis. The doses of methadone used in the first 24-48 hours of this study were insufficient for adequate symptom control. Despite a formal treatment protocol, there was substantial variability in total methadone exposure, length of treatment, and length of stay, suggesting other contributory factors for the observed variability.