Experts are questioning the use of Miralax in constipated children after an ingredient similar to antifreeze (Polyethylene Glycol) was linked to neuropsychiatric disorders and kidney side effects.
What is Miralax?
MiraLAX is an over-the-counter laxative sold by Merck & Co. It was approved in 1999 for short-term use in adults, up to 7 days at a time. The active ingredient is Polyethylene Glycol 3350 (“PEG 3350”), an osmotic laxative that works by pulling water into the bowel. This softens stools and stimulates bowel movements.
Miralax and Neurological Side Effects
Miralax is similar to the antifreeze chemical Ethylene Glycol (EG) and it may contain small amounts of EG and other toxins. There are reports linking Miralax and neuropsychological events, including children with symptoms of antifreeze poisoning, but the FDA has not recalled Miralax and rejected safety warnings in 2011.
Is Miralax Safe for Kids?
Miralax is NOT approved for kids and no one knows if it has short-term or long-term side effects in children. Miralax is poorly-absorbed by adults, but no one knows how it is absorbed by children with chronic constipation. Even so, 75% of pediatricians recommend Miralax for children, according to the New York Times.
Antifreeze Chemicals in PEG Laxatives
The FDA tested 8 batches of Miralax in 2008 after reports of children who had “classic symptoms” of antifreeze poisoning. All 8 batches tested positive for small amounts of Ethylene Glycol (EG) and Diethylene Glycol (DEG), which are toxic impurities left over from the manufacturing process for PEG 3350.
What is Polyethylene Glycol?
Polyethylene Glycol (“PEG 3350”) is a petroleum-based chemical that is absorbed by the body much differently than Ethylene Glycol (EG). Unlike this toxic antifreeze, PEG is not easily absorbed by the intestines of an adult. Even so, it is only safe for short-term and occasional use by adults.
So Why Is My Kid Sick?
Chronic constipation stretches out the intestines. This makes the intestines more porous (called “Leaky Gut Syndrome”) and increases the amount of PEG that could be absorbed from Miralax. The intestines of a young child are also naturally softer and more permeable than an adult, which could explain how so many kids were injured.
FDA Reviews Polyethylene Glycol Side Effects
The FDA Drug Safety Oversight Board reviewed the use of polyethylene glycol in June 2009 after receiving over 2,500 reports of adverse events. The board-members warned:
“Neuropsychiatric adverse events may include seizures, tremors, tics, headache, anxiety, lethargy, sedation, aggression, rages, obsessive-compulsive behaviors including repetitive chewing and sucking, paranoia and mood swings.”
Despite these serious safety concerns, the FDA took no action and closed their investigation into a possible risk of neuropsychiatric events from Miralax in August 2011. No warnings or recalls were issued.
Miralax and Metabolic Acidosis
The board also warned about metabolic acidosis, a condition in which the blood is too acidic. It is a severe side effect of antifreeze poisoning (ethylene glycol and diethylene glycol) that can cause rapid breathing, shock, or death. Metabolic acidosis can also be a mild or chronic disorder that is never diagnosed.
Parent Groups Demand FDA Recall Miralax
In June 2012, a consumer non-profit group filed a Citizens Petition (PDF) demanding that the FDA re-open the investigation, immediately recall Miralax and other PEG 3350 laxatives, add a “Black Box” against use in children, and update warnings about serious side effects.
Hospital Studies Safety of PEG Laxatives in Kids
In 2015, the FDA awarded $325,000 to the Children’s Hospital of Philadelphia to study how children absorb PEG laxatives, and also the risk of behavioral or psychiatric problems.
Neurological Risks of MiraLax in Children
- Neuropsychiatric disorders
- Brain injury
- Obsessive-Compulsive Disorder (OCD)
- Mood disorders
- Repetitive chewing and sucking
- Mood swings
Kidney Risks of MiraLax
- Acute Kidney Injury
- Kidney damage
- Acute kidney injury
- Kidney failure
- End-stage renal disease (ESRD)
- Oxalate nephropathy
- Kidney transplant
Ethylene Glycol Toxicity Symptoms
The symptoms of antifreeze poisoning can include kidney damage, brain damage, fast breathing, no breathing, bloody urine, low urine output, blurry vision, blindness, fast heartbeat, low blood pressure, coma, seizures, dizziness, fatigue, headache, slurred speech, unconsciousness, weakness, nausea, vomiting, and death.
Chronic Constipation in Children
Every child gets constipated once in a while, but frequent or chronic (long-term) constipation is not normal. It is usually due to dehydration, stress, diet changes, poor nutrition, or toilet training issues. Chronic constipation may be caused by underlying health problems, such as:
- Crohn’s disease
- Food allergies
- Celiac disease (gluten intolerance)
- Medication side effects
- Thyroid disease (hypothyroidism)
- Cystic Fibrosis
- Hirschsprung’s disease (congenital megacolon)
- Birth defects