Adjunctive Therapy for Patients With NAS

 Consider starting phenobarbital if polysubstance exposure is suspected or confirmed or if majority of NAS score is due to CNS disturbances (hyperactive reflexes, tremors, increased muscle tone, presence of jerks, etc).
 Loading dose (up to physician’s discretion if needed): 10 mg/kg/dose orally q12h × 2 doses
  Enteral formulation contains a high percentage of alcohol. Recommend dividing dose to decrease risk of emesis and/or sedation.
 Maintenance dose: 5 mg/kg/dose orally once daily, preferably in the evening. Dose may be divided BID if concern for excess sedation. Do not routinely weight adjust.
 Weaning: Recommend discharging infant home on phenobarbital with subsequent weaning to be done either in neonatal follow-up clinic or by infant’s primary care physician.
 Phenobarbital Levels: Drug levels should not be needed for this indication unless the infant experiences seizures or seizurelike activity. If suspected, a phenobarbital level and/or a neurology consult may be warranted at that time.
 Consider starting clonidine if the majority of NAS score is due to autonomic overstimulation (sweating, fever, yawning, mottling, sneezing, etc) and if infant is requiring >0.1 mg/kg/dose of morphine q3h and is still not stabilized.
 Maintenance dose (0.1 mg/mL suspension):
  Given that the infant will be receiving morphine on a q3hr basis, for ease of administration recommend 1 μg/kg/dose orally every 6 h (range: 4–6 μg/kg/day divided q4–6h)
 Side effects of clonidine include bradycardia, hypotension upon initiation, and then rebound hypertension when drug is discontinued.
  • BID, twice daily; CNS, central nervous system.