Bitter Pill

We’ve long been warned to avoid plastic water bottles and check the labels on body care products, both of which contain phthalates—a class of powerful endocrine-disrupting chemicals known to adversely affect hormone levels and fertility. Now, a sobering December 2008 report from the National Research Council (NRC) suggests
that phthalates are more potent than previously thought, and can trigger adverse effects at much lower exposure levels. The committee that wrote the report also reviewed animal data suggesting that exposure is cumulative, so contacts with phthalate compounds in multiple products can cause more serious toxic effects than using one or two products.

That’s bad news, because phthalates are everywhere, most commonly found in cosmetics, toys, plastics, and food packaging. Even worse, researchers have recently turned them up in a very unexpected place: prescription drugs. Could the drugs you’re taking to improve your health potentially worsen it?

Dr. Russ Hauser, professor of Environmental and Epidemiological Health at the Harvard School of Public Health, has been studying the effects of phthalates and other environmental chemicals on fertility and pregnancy for over a decade. He and his associates recently began to take a closer look at the ingredients in pharmaceutical drugs. Hauser and his team scour databases listing ingredients in medications to determine which medications may contain phthalates, then use data from prescription drug users’ urine samples to correlate their use of the suspected medications with urinary levels of phthalates. He mentions that there are hundreds of studies on phthalates in rats but only about a dozen or so studies that have explored health effects in humans.

Studies in lab animals show that exposure to phthalates causes infertility and a range of reproductive tract malformations, particularly in males. So far Hauser has tallied 47 meds approved by the FDA with ingredients—usually contained in a pill’s time-release coating—that could contain phthalates. Based on urinary analysis of prescription drug users, the most common medications Hauser’s team believes contain phthalates are Asacol, used for irritable bowel disease; Prilosec, taken for heartburn; and Respbid, a bronchodilator.

“We started these studies four years ago with a single medication, and we’ve now demonstrated that several meds have contributed to phthalate exposure,” says Hauser. During a 2003 study, one of Hauser’s test subjects showed levels of phthalates a thousand times greater than anyone else in study. The researchers concluded that the high phthalate levels resulted from the enteric time-release coating on the Asacol that he was taking for inflammatory bowel disease. The enteric coating is a barrier applied to drugs to control where it’s taken up in the digestive system. “Phthalates are present in time-release coatings because it’s part of the drug delivery system,” says Hauser. “The coating prevents the drug from being broken down in the stomach, so it will be delivered to the colon, the area of disease.”

Although the FDA does not currently regulate or test for phthalates, some officials and scientists are As of January 2009, California became the first state to ban products for children and babies that contain more than residual quantities of phthalates. In the same vein, the NRC is now urging the Environmental Protection Agency to reexamine the way it assesses phthalates’ toxicity to humans, and to prioritize cumulative risks rather than individual exposure. The European Union restricts the concentrations of several phthalates in children’s toys and has also banned phthalates from cosmetics.

Hauser mentions that he does not plan to notify the FDA of his findings, but he maintains that “Our role as researchers is to identify sources of exposure, whether it be from medications or other sources, and the FDA or EPA should use that information for risk assessment policy, policy setting, and potential regulation.”

Hauser and his group hope to assess over-the-counter drugs and nutritional supplements in the future, as well as generate a more complete list of which prescription drugs contain phthalates. Hauser wants to continue testing and research to draw more conclusive data about phthalates and cumulative risk exposure in humans. “We’d ultimately like to look at not only exposure but also potential outcomes: identify populations potentially exposed to phthalates
at high levels and look at potential health risks.”