There is no such thing as an absolutely safe drug. There never was, and I doubt that there will ever be one. Considering this opening statement, I would like to take you through an historical trip on the evolution of drug therapy, what the risks and benefits are, and what the new era of biotechnology has in store for us.
For centuries the art of medicine was practiced by many civilizations and cultures. Already five thousand years ago, the Chinese were using herb extracts to alleviate certain maladies, and the Emperor Shen Nung had encouraged the development of a lexicon of various potions and herb extracts for medicinal purposes. One such extract from the chang shang root was used to reduce fever. Today we know that this extract contained the powerful drug quinine. At the time, the Chinese medicine men did not know the chemical structure of this substance, but indeed they were aware of its beneficial effects.
Parenthetically, the ancient Chinese art of acupuncture has its genesis in a scientific principle, although it has gone unrecognized for several millenia.
A thousand years later the Egyptians at Luxor were using an extract from the Nile valley plant squill to overcome heart ailments. Although this extract proved to be quite effective, it did give rise on occasion to a nasty side effect, in this case cardiac arrest. We now know that the active principle is digitalis, which is a most effective heart stimulant, but the dose must be titrated very carefully because of its narrow therapeutic ratio. The Egyptians, using crude extracts, had no way of determining drug concentration, the consequence of which was inordinate risk relative to benefit.
Other civilizations have also left us records of their uses of medicinal plants. The antileprotic action of the chaulmoogra fruit was known to the ancient Indians and the ipecacuanha root was used in Brazil and the Far East for the treatment of dysentery and diarrhea. Its main alkaloid, emetine, still constitutes an important drug for these conditions.
Greek and Roman civilizations continued to use herbs and potions as well as metallic salts. In the apothecary shop of Galenus in second century Rome, another useful mixture resulted from the poppy plant for the treatment of pain. We know this substance to be morphine. He suggested that this extract, although it was a powerful pain reliever, also caused, when taken over an extended period of time, euphoria, excessive craving, and sometimes death,