HONOLULU -- There are no waiters or waitresses at Hale Noa, a quiet cafe northeast of Waikiki where an elixir known as awa is the only brew served.
Owner Keoni Verity makes patrons belly up to the bar for bowls of the earthy-tasting South Pacific drink. That way, he can see if they're still walking straight after their third, fourth or fifth refill.
"If they sit at a table and order many drinks without ever getting up, they sometimes don't realize how the awa is affecting them," Verity said.
The herbal root, also called kava outside Hawaii, is billed as a natural treatment for anxiety and insomnia. But some prosecutors think it may be too relaxing -- they're concerned about people driving after drinking it.
"I have no concern at all if people are sitting in a bar or a cafe and consuming kava to their hearts' content as long as they don't place other people at risk by getting behind the wheel of a car," said Jim Fox, the district attorney in California's San Mateo County.
There, Fox's office prosecuted a man accused of drinking 23 cups of kava tea before driving, then weaving onto a highway shoulder. In December, a judge threw out the DUI case, citing lack of evidence about the tea's effects.
A similar case against a kava tea drinker from San Bruno ended in a mistrial in October after the jury deadlocked.
Kava tea has long been used in South Pacific cultural and religious ceremonies. Known as a natural alternative to muscle relaxants and anti-anxiety medicine, it's lately been growing in popularity along with other herbal supplements. And in Hawaii, awa use is seen as part of a movement to revive native Hawaiian traditions.
Kava has varying degrees of potency, and the tea is the biggest concern. Kava tea is generally much more sedating than pills, Fox said. And Verity said a cup of kava tea at his bar is about four times more potent than a typical store-bought kava tea bag.
"Awa in general relaxes and soothes and creates a mild sense of euphoria and expansion, and you can kind of see that in the way people slow down a little bit both in their movement and their speech," Verity said. "People just generally get more mellow."
Kava does have a sedating effect, especially in the raw form, and can affect drivers in ways similar to liquor, said Keith Kamita, administrator of Hawaii's Narcotics Enforcement Division.
Hawaii law doesn't explicitly ban driving while under the influence of kava, Honolulu Deputy Prosecutor David Sandler said.
In most states, it is illegal to drive under the influence of any intoxicating substance, Sandler said. California is one of them; Hawaii is not.
"If you abuse kava, it's the same thing as abusing alcohol," he said. "The difference is in Hawaii we can't prosecute it."
Sandler said he didn't know of any specific cases of drivers getting into trouble after drinking kava. But he said it's hard to measure the kava problem because police don't test for the tea when pulling over drivers.
Verity said the problem can be solved with public education and sound policies at kava-serving establishments. He said he does not serve anyone under age 20 and asks customers if they plan to drive.
"One of the first things we do is caution against driving," he said.
Fox said he has endured a fair amount of ribbing for going after kava drinkers for DUI, but he believes the law is on his side.
"Unfortunately, it may require that somebody's actually killed before people become aware of the dangers of it, and that would be a tragedy," he said.
Physicians' Desk Reference for Herbal Medicines: http://www.pdr.net/
Hawaiian Kava Center: http://www.hawaiiankavacenter.com/