Opiates appear to better "ameliorate the withdrawal, facilitate feeding and potentially reduce the likelihood of seizures," according to two new systematic reviews done by David Osborn, a neonatologist at the Royal Prince Alfred Hospital in Sydney, Australia, and colleagues.
The researchers also found that infants treated with opiates regained birth weight more quickly than those who only received supportive care.
According to their analysis, the use of opiates instead of sedatives or supportive care alone shortens the duration of supportive care by an average of four days. When compared to diazepam (Valium), opiates reduce the incidence of treatment failure.
However, infants treated with opiates had longer hospital stays than those treated with phenobarbitone, the sedative most often used in these cases. When sedatives only were compared, phenobarbitone was more likely than diazepam to reduce treatment failure.
The reviews appear in the July issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The reviews included 13 studies with a total of 890 infants of mothers who had used opiates with or without other drugs (including antidepressants, sleep aids and marijuana) during pregnancy. Researchers say two of the studies may have included identical patients.
Newborns suffering from neonatal abstinence syndrome (NAS) exhibit seizures, poor feeding, diarrhea and vomiting that lead to excessive weight loss and dehydr ation, sleeping problems and fever. Disruption in the mother-child bonding process has also been reported, and there is an increased risk of sudden infant death syndrome.
In the studies, newborns suffering from NAS were treated with opiates (morphine, methadone, paregoric, or tincture of opium), sedatives (phenobarbitone, diazepam or chlorpromazine) or supportive care only. None of the studies compared opiate treatment with placebo.
Of the randomized and "quasi-random" studies analyzed, "the evidence is not high quality," Osborn says, and unanswered questions remain. For example, in infants treated with an opiate, the addition of phenobarbitone may reduce withdrawal severity, but more research is needed using a higher initial dose of opiate, and to examine the effects of phenobarbitone on infant development.
In the 1999 U.S. National Household Survey on Drug Abuse, 3.4 percent of pregnant women reported illicit drug use in the past month, which according to authors represents some 3,000 current pregnant heroin users in the U.S., similar to Australian figures. Between 48 percent and 94 percent of infants exposed to opiates in the uterus develop clinical signs of withdrawal
"The interesting information," Osborn says, "suggests that these infants can be treated without admission to the special care nursery unless withdrawal is complicated and that this is facilitated by use of morphine instead of phenobarbitone. This helps keep mothers and babies together, helps in educating the mothers in mothercraft skills and to recognize signs of infant withdrawal, and helps in assessment of the quality of the mother-infant interaction in a supervised environment."