Miralax is an over the counter powder used to treat constipation. It previously was a prescription product and has been prescribed or recommended by pediatricians since the late 1990s. The active ingredient is polyethylene glycol 3350 ("PEG 3350"), which works by pulling water into the intestines. This softens the bowel movements and makes them more likely to happen regularly. Over the years, many of our toddlers, children, and teens have used Miralax to help with constipation. It is the most frequently recommended laxative for children by both pediatricians and pediatric gastroenterologists. One of my own sons took the medication regularly (essentially daily) for many years. He found it so helpful and was a normal part of his routine that he referred to it as his "Magical Pooping Powder".
Despite the years of use and how often doctors recommend it for persistent (daily) use, it is not technically FDA approved for that use. Is that a problem? I would tell you probably not. We have an odd way of approving medications for use in this country. Many medications used for years in this country that have a good, safe "track record" have not been FDA approved for a certain use. A good example is amoxicillin use for sinus infections. It is used all the time, is recommended by the specialists, and has been safely and effectively used for years. It is not approved by the FDA for this use. Does that mean it has not been safe? No. The companies manufacturing the amoxicillin would need to spend hundreds of thousands of dollars to do the research to submit to the FDA to have this approval happen. Why don't they do that? It is so expensive and it would be unlikely to change how it is used by the doctors, so there is very little motivation to spend the time and money.
In fact, at one point it was estimated that nearly 80% of the medications commonly used by pediatricians were not used "just" according to FDA approval. They may be used at different ages (clotrimazole states not to use on a diaper rash without it being recommended by a physician -- we do so all the time), for different diagnoses (approved for ear infections but used for sinus infections), for longer amounts of time (over the counter antacids are approved for use up to 14 days but are taken all the time for daily use), and other variations. The truth is pediatricians have so much good experience with these medications that we fill very comfortable recommending and prescribing them.
There was an article in the New York Times in 2012 about this issue and Miralax. A link to it is here. My worry is that a safe, effective medication will no longer be used when the other options become more frequently used after concerns are raised. And despite 15 years of its use, no good studies have raised any worrisome concerns. I am always skeptical of individuals or groups blaming side effects on a medication or treatment and then it getting over-blown. Also, it is always important to remember that if a symptom or health issue starts while using a medication or undergoing a treatment, it does not mean the medication or treatment caused it.
So further study into the safety of Miralax and PEG 3350 is going to occur. Here is another recent New York Times article about it. In the meantime, based on 15 years of experience and my reading, I will continue to recommend Miralax as I have found it safe and effective for my patients and family members who need it. If you are concerned about using Miralax at this time, there are other options listed on my "Constipation" protocol on the Hilliard Pediatrics website, available here.