Dr. Victor Navarro, MD, a hepatologist at the Einstein Healthcare Network in Philadelphia, spoke at the International Conference on the Science of Botanicals in Oxford, MS, Tuesday. The conference is hosted by the National Center for Natural Product Research which is connected to the School of Pharmacy at the University of Mississippi.
Navarro is the head of the Drug Induced Liver Injury Network, a national reporting system linking six clinics across the country. The network collects information on liver injuries to try to spot safety problems and to share information about how best to treat patients with this health concern.
Over the years Dr. Navarro has noted a rise in the percentage of cases that can be attributed to this category of products. He has presented his data at the botanical meeting before and has gotten a significant amount of pushback on how he categorizes the products.
About half of the supplement products that cause issues in the cases that Dr. Navarro and his colleagues gather data on are in the bodybuilding category. Many of these are spiked with anabolic steroids.
Legitimate players in the industry counter that these are not dietary supplements at all but are rather illegal drugs. Navarro noted the criticism, though he has observed that these products are marketed as supplements and seem to be understood that way by the people who consume them. And he has to call them something.
“I’m waffling about whether we should call these HDS (Herbal Dietary Supplements) because of some of the criticism I’ve gotten from people in this room,” Dr. Navarro said.
Finding a safety signal in the noise
Dr. Navarro said teasing out how these supplement-like products can cause injury is difficult. As health records become more automated he said it's becoming easier to, with a few keystrokes, figure out what drugs have been prescribed for a particular patient. With supplements, there is almost never a record beyond the patient’s personal recall.
“We are almost never dealing with a patient that is taking just one supplement,” Dr. Navarro said. “And with some of these products we are dealing with hidden or undeclared ingredients.”
“Nevertheless, as we encounter more patients with liver injury we are starting to see patterns of injury,” Dr. Navarro said. One pattern that presents over and over with the bodybuilding products is that of young men who come to the clinics.
“They’re young, they’re fit, they’re jaundiced, they’re itching. After they stop taking the offending supplement, they generally get better,” he said.
Dr. Navarro’s tone in giving the talk has changed over the several years he has participated in the event, something that other stakeholders have welcomed. In his first appearances he presented a picture of a harsh critic who was sounding the alarm about an industry asleep at the safety switch. The current iteration of his talk was presented in a tone of providing information that industry can use to identify problem products and ingredients and deal with them.
“This last talk was much more collaborative in tone,” said Dr. Rick Kingston, PharmD, who is a professor at University of Minnesota as well as being the president of scientific and regulatory affairs for the firm SafetyCall International.
Dr. Navarro said the percentage of liver injury cases attributed to his self defined supplements category has held steady now for the past three years at about 20%, after rising for several years in a row. And he stressed that this is a very discrete data set, and can’t be extrapolated to the wider market.
“I can’t tell you the incidence of liver injury attributable to dietary supplements in the U.S.,” Dr. Navarro said. “Our denominator is patients who have been referred to physicians with liver injury.”