The headlines read: “Coma from the Health Food Store: Interaction between Kava and Alprazolam.” First published as a letter to the editor of a prominent medical journal in 1996, the story made national news. While the truth is somewhat more complicated, the accusation had been made, and an herbal medicine was implicated as a danger to public health.
Unfortunately the stigma continues. Recently I recommended kava root extract (Piper methysticum) to one of my patients in need of a mild tranquilizer. “I’m afraid to take that stuff,” she explained. “I just saw a poster hanging on the wall in another doctor’s office that said, “beware, kava causes coma.” Although the statement is absurd, the realization that comments like this are presented to the public as fact is frightening.
Examining the Case
So what were the actual facts of that case? A fifty-four-year-old man was hospitalized in a “semi-comatose” state, which the authors described as “lethargic and disoriented.” He was never in a coma—the term semi-comatose appears to have been an exaggeration. He began to improve within a few hours, apparently without any specific medical intervention.
The patient had been taking a combination of three prescription drugs: alprazolam, a potent tranquilizer popularly known as Xanax; terazosin, a blood pressure medicine; and cimetidine, an antacid. According to the Physicians’ Desk Reference (Medical Economics Company, 52nd edition, 1998), the numerous side effects of alprazolam include impaired coordination and memory, drowsiness, and fatigue. Likewise, the side effects of terazosin include weakness, tiredness, lassitude, and fatigue. And cimetidine is notorious for its effect on the metabolism of other drugs, such as the benzodiazepine class of tranquilizers that includes alprazolam. By inhibiting the breakdown of those drugs in the liver, it’s as if a much higher dose was being taken, thus increasing the risk of side effects.
To this pharmacologic mixture, the patient added kava, which he purchased from a health-food store in an unknown form and dosage. He claimed he hadn’t taken more than the recommended amount. Three days after starting the kava, his symptoms developed. Consequently, the blame was placed on kava.
The rundown on kava
Given what is known about kava, is there reason to be concerned? Taken in sufficiently high doses—such as those used in the traditional ceremonies in the South Pacific—kava root certainly can be intoxicating, resulting in sedation and profound muscle relaxation. What is more, its active ingredients, the kavalactones, may have biochemical effects in the brain that are similar—though not identical—to those of medications like alprazolam.
However, the similarity ends there. While medical studies have shown that kava can alleviate anxiety as well as prescription tranquilizers, it’s not addictive, and it doesn’t impair mental function or coordination in the dose typically recommended, which is 45 to 70 mg kavalactones, up to three times daily. In fact, many people actually report increased alertness and improved concentration after taking kava. So, instead of being dangerous, kava may be safer and equally effective as drugs that are much more toxic.
The question is, why would anyone want to take kava at the same time as a benzodiazepine or any other prescription tranquilizer? Common sense should predict that the effects would be additive and possibly synergistic. This also holds true for combining kava with alcohol, barbiturates, sleeping pills, and major tranquilizers, such as those used to treat schizophrenia. In other words, I would advise against taking any of these substances together.
In defense of herbs
That being said, the disturbing issue for me is an attitude that views herbs as inherently suspect whenever an adverse event occurs. According to this school of thought, all herbal medicines are nostrums: unproved quackery with potentially dangerous side effects. To arrive at that conclusion, one has to ignore years of solid research published in respectable medical journals. Yes, it’s true, prescription drugs usually have much more detailed research behind them, but that doesn’t mean they are any safer or more effective than herbs.
Interestingly, herbalists often combine kava with other herbal nervines—agents that calm the nervous system—such as valerian root (Valeriana officinalis), hops (Humulus lupulus), and skullcap (Scutellaria lateriflora). Often the combination is more effective than the individual herb, without any evidence of increased toxicity. Contrast this to the thousands of overdoses—many resulting in fatalities—that occur each year from people combining various prescription medications.
Now that you have the facts, you might well wonder why the editor’s choice for the headline wasn’t: “Coma from the Drugstore.”
Robert Rountree, M.D., is a physician at the Helios Health Center in Boulder, Colorado, where he practices integrative medicine. He is coauthor of Smart Medicine for a Healthier Child (Avery, 1994), and an Herb Research Foundation advisory board member.