ADVERSE DRUG REACTIONS
The size of the problem
Any substance that possesses useful therapeutic effects may also produce unwanted, toxic or adverse effects. The incidence of adverse drug reactions in the population is not really known. A survey of 1160 patients given a variety of drugs showed that the incidence of adverse reactions increased with age from about 3% in patients 10- 20 years of age to about 20% in patients 80-89 years of age. It has been estimated that about 0.5% of patients who die in hospital do so as a result of their treatment rather than the condition for which they were admitted.