The average physician has some 50,000 drugs from which to choose when writing out a prescription. Few are able to make effective use of more than 100.
In many countries the proliferation of drugs results in prescriptions that read like a shopping list, and in many unnecessary "medicines" being sold. In 1982 the Bangladesh government reckoned that one third of the money spent on drugs was wasted on totally useless tonics, vitamins and other dubious preparations.
The proliferation in the use of medical drugs is a result of: over-prescription by doctors; the discovery of new drugs (a boom over the last decade); an increase in concern about and awareness of personal health on the part of the general public; and increasing belief in the efficacy of drugs for the majority of physical and psychological disorders on the part both of doctors and the public. Although the World Health Organization has drawn up a "Model list of Essential Drugs", with only some 220 drugs and vaccines, pharmaceutical companies continue to produce new variations and the total marketed worldwide is around 30,000.
The over-prescription by doctors is not a guiding force in the development of new drugs. It is a fact that new drugs coming on the market are more efficient the previous ones, otherwise they would not be approved for market.