Herb-drug spectrum

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For the past three years, this column has been exploring the issue of the complex interactions between herbs and drugs. I must admit to holding an ulterior motive for writing about this topic: I have wanted to provide a counterpoint to the current trend of herb-bashing. Even though herbs and drugs can be used together in ways that are synergistic and mutually beneficial, the popular press has frequently focused on the negative or antagonistic aspects of their interactions. Some self-proclaimed authorities have unfairly maligned herbal medicines by repeatedly characterizing them as being toxic, ineffective, or both. By emphasizing the facts over biased opinions, I have hoped to set the record straight.

It is relatively easy to perpetuate canards about the dangers of herbal medicines. Isolated reports of negative reactions make national headlines without a reasonable attempt to verify their accuracy. Once published, these reports transform into standing waves that echo and reverberate throughout the popular and medical literature, regardless of whether they have ever been subjected to rigorous scientific scrutiny.

Remember the man who became temporarily lethargic after adding some kava (Piper methysticum) to his regular daily cocktail of three prescription drugs (which included a tranquilizer)? Despite the fact that after a few hours he fully recovered without any need for intervention, the published case report was entitled, “Coma from a Health-Food Store,” a headline that made national news. It wasn’t long before many medical doctors began displaying posters in their offices that stated, “Beware, kava causes coma.” (I’m not making this up!)

In contrast, before significant reactions to a prescription medicine get publicized, a fairly large number of them must occur. Consider phenylpropanolamine, a popular decongestant and weight-loss medication. It was sold over-the-counter for years before mounting reports of toxicity and deaths led to its removal.

The underlying implication is clear: It is acceptable for synthetic medications to have a certain level of toxicity. This explains why the medical community speaks in terms of the “risk/benefit ratio” when describing a drug’s effects. But when someone has a negative reaction to an herb, we are quickly reminded that the herbal industry is unregulated and that taking “unproven” remedies produced by such an industry constitutes inherently risky behavior. The worst-case scenario is when an herb appears to interfere with a drug. In this situation, the typical recommendation is to avoid taking the herb. While the herb is viewed as dispensable, the drug isn’t questioned.