Neonatal withdrawal

Neonatal withdrawal or neonatal abstinence syndrome (NAS) is a withdrawal syndrome of infants, caused by the cessation of the administration of licit or illicit drugs. Tolerance, dependence, and withdrawal may occur as a result of repeated administration of drugs or even after short-term high dose use—for example during mechanical ventilation in intensive care units. There are two types of NAS: prenatal and postnatal. Prenatal NAS is caused by discontinuation of drugs taken by the pregnant mother, while postnatal NAS is caused by discontinuation of drugs directly to the infant.^[1][2]

The drugs involved may be for example opioids, selective serotonin reuptake inhibitors (SSRIs), ethanol and benzodiazepines.^[1][3] Neonatal abstinence syndrome does not happen in prenatal cocaine exposure (with babies exposed to cocaine in utero) in the sense that such symptoms are difficult to separate in the context of other factors such as prematurity or prenatal exposure to other drugs.^[4]

When pharmacological treatment of opiate withdrawal in neonates is deemed necessary, opiates are the treatment of choice; they are slowly tapered down to wean the neonate off opiates.^[5] Phenobarbital is sometimes used as an alternative but is less effective in suppressing seizures; however, phenobarbital is superior to diazepam for neonatal opiate withdrawal symptoms. In the case of sedative-hypnotic neonatal withdrawal, phenobarbital is the treatment of choice.^[6][7] Clonidine is an emerging add-on therapy.^[8] Buprenorphine is under development as an alternative to morphine or methadone as initial therapy.^[9]

Opioids such as neonatal morphine solution and methadone are commonly used to treat clinical symptoms of opiate withdrawal, but may prolong neonatal drug exposure and duration of hospitalization.^[10] A study published in the Journal of Pediatric Pharmacology and Therapeutics demonstrated a significantly shorter wean duration in infants treated with methadone compared to those treated with diluted tincture of opium. When compared to morphine, methadone has a longer half-life in children, which allows for less frequent dosing intervals and steady serum concentrations to prevent neonatal withdrawal symptoms.^[11]

Non-pharmacological approaches to treat neonatal symptoms include swaddling the infant in a blanket, minimizing environmental stimuli, and monitoring sleeping and feeding patterns.^[12] Breastfeeding promotes infant attachment and bonding and is associated with a decreased need for pharmacological treatment. These approaches may lessen the severity of NAS and lead to shorter hospital stays.^[13]

A 2012 study from the University of Michigan and the University of Pittsburgh published in the Journal of the American Medical Association analyzed information on 7.4 million discharges from 4,121 hospitals in 44 states, to measure trends and costs associated with NAS over the past decade. The study indicated that between 2000 and 2009, the number of mothers using opiates increased from 1.19 to 5.63 per 1,000 hospital births per year. Newborns with NAS were 19% more likely than all other hospital births to have low birthweight and 30% more like to have respiratory complications. Between 2000 and 2009, total hospital charges for NAS cases, adjusted for inflation, are estimated to have increased from $190 million to $720 million.^[14][15]

References

Neonatal Jaundice