[Herb-drugs interactions].

Herbal therapeutics are increasingly associated with herb drug interactions. The vast majority of the purported cases is unsubstantiated and misinterpreted. Pharmacological and clinical studies should only be demanded in cases of reliable evidence. First steps to be taken by manufacturers of herbal drugs should be in vitro studies with metabolizing systems like CYP and P-gp. Manufacturers of drugs that are metabolized by modulated systems should be requested to conduct drug specific interaction studies as necessary.