Neonatal abstinence syndrome (NAS)

P96.1

DESCRIPTION

Postnatal opioid (or non-oipioid illicit drug) withdrawal syndrome occurring in 55-94% of newborns whose mothers were addicted to or treated with opioids or other non-opioid illicit drugs, during pregnancy.

Can result in:

  • foetal malformation,
  • intrauterine death,
  • preterm delivery,
  • growth restriction, and
  • an increased risk of antepartum haemorrhage (APH).

After birth withdrawal symptoms are most commonly associated with opiate exposure, but can occur with a wide range of substances including SSRIs which have a separate guideline. Babies developing Neonatal Abstinence Syndrome (NAS) risk subsequent morbidity and SIDS mortality. A multi-disciplinary approach is needed to optimise care for often complex social, psychological and support issues.

DIAGNOSTIC CRITERIA

Mother

  • Assessing the mother's drug use – especially during pregnancy
  • The mother's urine may be screened for drugs as well.

Newborn include:

  • Neonatal abstinence syndrome scoring system (Modified Finnegan can be used)), which assigns points based on each symptom and its severity. The infant's score can help determine treatment.
  • Toxicology (drug) screen of urine and of first bowel movements (meconium).

GENERAL AND SUPPORTIVE MEASURES

  • At birth record maternal past and current drug use, dosage and route including time of last use. Partner’s drug use – consider adding it to the Road to Health Chart
  • Record relatives’ awareness of maternal drug use.
  • Check and document mother’s viral status and offer Hepatitis B vaccine
  • (Cross reference: Local Hepatitis B, C, HIV management guidelines)
  • Record mother’s choice of feeding method, noting prior discussions and decisions.
  • Collect urine sample from baby within 48 hours to check drug exposure
  • (maternal consent, check antenatal record of discussion)
  • Commence withdrawal observations 4 hourly/1-hour post-feed times for at least 72 hours and record severity level. See Table 2 for guidance.

Table 2: Timing of symptoms onset

Typical timing of
symptom onset 		Substance
3 - 72 hours Alcohol, Heroin, Morphine, Buprenorphine, Codeine,
Diazepam, SSRIs
24hours - 21 days Methadone, Benzodiazepines, Barbiturates

MEDICINE TREATMENT

Withdrawal symptoms are reduced when drugs from the same group are re-introduced. Heroin is the most commonly abused illicit opioid in South Africa and is referred to as “unga” or “Thai white”. “Sugars” is a mixture of cheap heroin and cocaine that can be cut with a variety of other substances that may even include rat poison or other household detergents. “Nyaope” is a mixture of cheap heroin and cannabis that is commonly used is Gauteng. This mixture is also referred to as “Pinch” in some areas. There is debate about the exact content of the street drug, “Woonga”. It is thought to consist of a number of different substances, that may include heroin, crystal methamphetamine as well as rat poison and antiretroviral medications, specifically efavirenz.

Medicine treatment of NAS

PROBLEM DRUG TREATMENT OPTIONS
Opiate withdrawal
  • Morphine Sulphate


    • 40mcg/kg/dose 4 hourly

    • Increase dose 20- 40mcg/kg/dose 8 hourly until symptoms controlled

    • Maximum dose: 100mcg/kg/dose


    [Addition of Phenobarbitone may reduce symptom severity]
    Non-opiate withdrawal

    • Phenobarbitone


      • 20mg/kg orally loading dose

      • maintenance dose 24 hours later

      • 4mg/kg daily in 2 divided doses
    Seizure management
      Any seizures should be fully investigated:
    • Refer to Seizures, Neonatal

    • Phenobarbitone


      • 20mg/kg orally loading dose

      • maintenance dose 24 hours later

      • 4mg/kg daily in 2 divided doses


      For opioid withdrawal:
    • Morphine sulphate (for opiate withdrawal) 100mcg/kg stat dose oral/IV according to clinical status


      • If on maintenance morphine sulphate consider increasing dose

    Weaning Process

    • Decrease dose NOT dose interval time.
    • Discuss weaning difficulties with a specialist.

    Weaning regimen

    DRUG WEANING REGIMEN
    Morphine sulphate After 24-48 hours of symptom control reduce dose by 10-20% each 24-48 hours as tolerated until dose of 20 mcg/kg Reached. Then reduce frequency until 40 mcg/kg/day/stable to discontinue
    Phenobarbitone After 24-48 hours stability reduce dose by 2mg/kg/dose 48 hourly as tolerated

    Notes

    • Continue NAS assessments for 48 hours after discontinuing medication.
    • Ensure hepatitis B immunisation is given when due.

    REFERRAL

    • All neonates with repeated seizures