It's commonly acknowledged that alternative medicines such as botanical dietary supplements are not as regulated or researched as prescription medicines, and that almost no one knows much about how well they work.

 

One Arkansan, though, knows more about the field than almost anyone else on the planet.

 

Bill Gurley, PhD, is director of the Clinical Pharmacokinetics Laboratory in the Department of Pharmaceutical Sciences, UAMS College of Pharmacology. For the past 10 years, the program he leads has been a pioneer in evaluating the efficacy and interactivity of botanical supplements with conventional medications.

 

"We've managed to carve a significant niche," Gurley said of his group. "We have in fact done more clinical studies in this area than anyone else in the world."

 

The group was one of the first to report and document serious interactivity problems with St. John's Wort, and the FDA used their research during the "ephedra wars" for their more restrictive ephedra regulations.

 

"There are basic issues with the way a lot of dietary supplements are formulated," Gurley explained. "Some have no interactivity problems whatsoever – but this too often can be because they have nothing in them."

 

Supplements must be evaluated for their own efficacy, much of which is determined by how well they dissolve inside the body. If – as is often the case, Gurley said – they don't dissolve well at all, they probably won't have much effect for the patient, but they also aren't likely to have interactivity problems with prescription pharmaceuticals. If they do dissolve well, the supplements may or may not achieve the desired clinical effect for the patient, but the likelihood they will negatively affect or neutralize other medications goes up significantly.

 

It is research that will never end. Ultimately, each brand and variation of each supplement must be evaluated with every pharmaceutical. It's a daunting task, but one Gurley's group is attacking systematically.

 

The pharmacological formulation of the supplements is at the heart of the research. Gurley said many clinicians and patients alike assume that supplements have the same formulation as conventional medicines – the same time-release properties, for example – but this is often not the case. Studies that are limited in their scope also confuse the issue for many clinicians who see published research with completely contradictory information on a supplement like Ginkgo biloba.

 

"Formulation is key to the efficacy of botanicals," he said. "There's a lot of confusion, mixed messages. If you're comparing two supplements and one dissolves better, it's going to have different efficacy and thus different interactivity than the other. Not all supplements are created equal, even those with the same advertised properties." A study that only evaluates a single formulation is helpful information, but not to be considered conclusive for the botanical as a whole.

 

Other studies may document a supplement's efficacy or interactivity in small animals or in the laboratory, without taking into consideration the bigger picture. "The effect may be discernible, but it may not be clinically significant," Gurley said. "We evaluate for clinical significance, because that's what matters."

 

He said there's a real problem in getting accurate information from patients about what they are taking in addition to their prescriptions.

 

As much as 20-30 percent of people on prescription drugs also take dietary supplements. Seventy percent of people taking dietary supplements also take prescription drugs.

 

But Gurley said studies showed that only half of all patients taking dietary supplements report it to their physician.

 

The reasons for this are multiple.

 

"They think the physicians look down on botanical supplements – and there's probably some truth to this – and they don't want to get lectured to. They don't think of them as medicine, so they may not think to tell the physician; very few realize that interactivity issues exist," Gurley said.

 

"Physicians must make an extra effort with their patients to make sure their patients are being forthcoming and forthright about non-prescription supplements they may be taking."

 

Gurley's group is currently putting together an application to the National Institutes for Health for a five-year, approximately $10 million grant to found  a large center on botanical pharmaceuticals in conjunction with the National Center for Natural Products Research at the University of Mississippi.

 

He said the group at Old Miss is also a world leader in the field, but that their work centers on laboratory, test tube and small animal research. "They do lab research, but no human clinical trials, whereas we do clinical trials in humans, but no test tube or small animal research," he explained. "It's a good collaboration because our work complements each other so well."

 

The center would be on both campuses, with all the clinical studies taking place at UAMS.

 

Besides the daunting task of evaluating the efficacy and interactivity of every supplement with every drug, Gurley said the field is about to change tremendously because of revolutionary new manufacturing techniques, processes and protocols to increase the water solubility of many dietary supplements.

 

"Nobody is really talking about this yet, but it's going to have a big effect on what patients experience," Gurley predicted. "By changing the bioavailability of phytochemicals, it changes the playing field completely. They may make the supplements work better on their own, but that can greatly increase the chance they're going to have problems when combined in the body with certain prescription drugs. We may start seeing much more interactivity complications."

 

Another subset of research is herb-herb interactions.