Toxcity risks and adverse effects

Herbal medicine is not free from toxicity. A natural poison can kill as efficiently as a synthetic one. Many herbal remedies can cause harmful drug interactions when accidentally substituted or taken along with conventional medicines. Eg., Aristolochia fangchi when consumed as a substitute for an anti-density chinese herb has been reported to induce chronic nephropathy in women. Likewise St. John’s wort products decrease plasma concentrations of several prescription drugs such as alprazolam, cyclosporine, dijoxin, oral contraceptions etc. This is because hyperforin in St. John’s wort induces cytochrome P450 enzymes.

Common fruits like cranberry also interfere with this enzyme – critical to drug metabolism. This is a cause for concern when such fruits are taken along with many herbal drugs.

Herbal drugs in widespread use are also associated with adverse reactions. Eg., Chronic liquorice ingestion is attributed with potassium depletion.