Miralax is seen on a store shelf. (Robin Lubbock/WBUR)
By Ricki Morell
If you, like millions of parents, routinely give your child Miralax for constipation, recent reports that the Food and Drug Administration is studying a possible link between the common laxative and neuropsychiatric problems probably sounded scary.
After years of complaints from activists, two Children’s Hospital of Philadelphia researchers are now leading an FDA study of the ingredient — polyethylene glycol 3350, or PEG 3350 — to see how it affects children.
“We’re pleased that they’re going to be looking at behavior changes because that’s never been done before,” said Carol Chittenden, co-director of The Empire State Consumer Project, a nonprofit consumer group in Rochester, New York, that pushed the FDA to embark on the study. “Parents are feeling anxious but also validated because they’ve been telling their doctors for years about these symptoms.”
Just because the FDA is doing a study, doesn’t make it dangerous.
– Dr. Samuel Nurko
Miralax is sold over the counter as an adult laxative, but pediatricians and gastroenterologists routinely prescribe it to infants, toddlers and older children. And they often prescribe it for long-term daily use for chronic constipation, even though the label says it should be used for no more than seven days “unless advised by your doctor.”
Dr. Samuel Nurko, director of the Center for Motility and Functional and Gastrointestinal Disorders at Boston Children’s Hospital, said parents have little reason to worry. Dr. Nurko, who was involved in previous studies of Miralax, some partially funded by the drug company that used to own Miralax, argues that the drug isn’t approved for children because of the technicalities surrounding the FDA study process. He believes Miralax is safe for children.
“Just because the FDA is doing a study, doesn’t make it dangerous,” Dr. Nurko said. “From my perspective, the risk of not treating constipation is worse. Do you think the FDA would leave it on the market if it were dangerous? I think it’s an overreaction but I’m glad that they are studying it.”
About 5 percent of children suffer from constipation, according to the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, which has guidelines for long-term use of Miralax among other constipation treatments.
FDA spokesperson Andrea Fischer said in an email that the agency is funding the $325,000 study to explore pediatric safety concerns even though “the FDA has not determined that there is enough data to warrant additional warnings regarding these products, or to issue specific warnings about pediatric use of the drugs at this time.”
The FDA first tested Miralax in 2008 and found small amounts of ethylene glycol and diethylene glycol, toxic ingredients also found in antifreeze. In subsequent tests in 2013, it found no detectable levels of those ingredients.
Chittenden says any hint that PEG can lead to side effects known to be associated with ethylene glycol or diethylene glycol toxicity is disturbing. According to a 2009 FDA drug oversight report, neuropsychiatric side effects “may include seizures, tremors, tics, headache, anxiety, lethargy, sedation, aggression, rages, obsessive-compulsive behaviors including repetitive chewing and sucking, paranoia and mood swings.”
Diethylene glycol toxicity can also cause “metabolic acidosis,” or too much acid in the blood, which, in severe cases, can lead to shock or death.
But Fischer emphasized that the link between these side effects and Miralax is so far unproven. Continue reading