The scientific evidence of a causal link between usage of kava kava and liver damage may not be solid enough to support the first-of-its-kind case of a Florida man who claims the herbal supplement killed his wife.

Anthony Starks has sued the manufacturer of the “Happy Camper” kava product, alleging it was defective and carried inadequate warnings of the risk of liver failure. His wife Laura, 57, died in November 2005 after using the product regularly for about 18 months.

“Had Mrs. Starks been properly warned by Defendant ... Mrs. Starks would not [have] ingested the supplement and would not have sustained acute liver failure and died,” the complaint, filed last month in Orange County Circuit Court, says.

At the time Laura Starks was buying the supplement, the label warned only against its use by persons under 18 and consumption with alcoholic beverages. The manufacturer, Natural Balance of Castle Rock, Colo., now tells consumers, in language taken from an FDA advisory:

Kava-containing products may be associated with a very rare type of liver injury.

In May 2006, kava manufacturers including Natural Balance, distributors and retailers settled class-action claims of inadequate warning labels for $717,000. And the change in the “Happy Camper” label may help Anthony Starks' case.

“They can't make the argument that it didn't need a [liver injury] warning,” says his attorney, Joseph H. Saunders (Saunders & Walker, Pinellas Park, Fla.).

But no matter how strong the failure-to-warn argument may be, the evidence of causation certainly appears weaker than in, for example, ephedra products liability cases.

The complaint cites, among other things, the FDA advisory, the United Kingdom's ban on sales of kava-containing products, and a British medical journal article reporting that a 50-year-old kava user suffered acute liver failure.

Saunders also denies that any other health problems could have caused Laura Starks' death. “She was a very healthy 57-year-old,” he insists.

In a 2002 study of reports of kava-associated adverse events, however, toxicologist Dr. Donald Waller concluded that

based on currently available information ... kava when taken in appropriate doses for reasonable periods of time has no scientifically established potential for causing liver damage.

According to another researcher, “[I]n contrast to both benzodiazapines and antidepressants, kava possesses an excellent side-effect profile.”

By Matthew Heller
1/21/07