Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this group will receive methadone oral solution (0.4mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 8 hours depending on the severity of the Finnegan scores. To maintain blinding of the two study arms, a "double dummy" design will be used - each infant will receive both methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS as needed. Infants will be weaned by 10% of the maximum dose once every 24-48 hours and the medication will be discontinued once at 25% of the maximum dose.

Infants randomized to this arm will receive neonatal morphine solution (0.2mg/mL) for first line therapy. Infants will be scored using the standardized Finnegan scoring system and will be initiated on treatment if they have 2 consecutive scores greater than or equal to 8 or 1 score greater than or equal to 12. Dosing will be weight and symptom based. A "double dummy" design will be used - each infant will be ordered for both a methadone/placebo study drug at 0.4 mg/mL and a morphine/placebo study drug at 0.2 mg/mL. Starting doses will range from 0.3mg/kg/day to 0.9mg/kg/day divided every 4 hours depending on the severity of the Finnegan scores. Doses will be increased to a maximum of 0.9mg/kg/day for continued scores generally >8 caused primarily by worsening NAS. Infants will be weaned by 10% of the maximum dose once every 24 - 48 hours and the medication will be discontinued once at 25% of the maximum dose.