I don't think that this is a case of either the pharmaceuticals or the herbs being "dangerous" in and of themselves. But, the interaction between some particular drugs and these herbs or other naturally occurring foodstuffs, can have some adverse effects - some of which might even be deadly.
It is definitely the case that these drugs are dangerous. When taking Coumadin all herbs are contraindicated. As Habibi’s post #14 testifies to even many common foods are contraindicated. That was my original point. The article speaks of herbal medicines but lists some, that I referred to, which are themselves common foods. That says more about the drugs than it does about the herbs. Anyone taking them needs to be very cautious, informed and disciplined.