One of the greatest advances in Geriatric Medicine during the last
quarter of a century has been the increased realization of the
possibilities of treatment for elderly patients. Neglect has been
replaced by a more optimistic therapeutic endeavour and countless old
people have benefitted from this approach. But there is also a drawback,
and this is the risk of hazardous side effects of medication which are
often directly proportional to the biological potency of the drug and
may be unpredictably increased due to changes in the senile organism. In
fact the anatomical and biological changes in old age alter both the
kinetics of most drugs and the receptor response. On account of these
changes the individual tolerance of aged patients to drug therapy may be
quite different from that of younger subjects. Thus for a variety of
reasons elderly patients receive more drugs, but they are at a higher
risk of encountering adverse reactions, which often show atypical
clinical features. We can therefore speak of "geriatric iatrogenic
disorders" and point out that some of these side effects are determined
by a complex pathogenesis due to the particular pathophysiological
condition in the elderly. It is important to encourage the habit of
individ- ually evaluating potential risk versus expected advantages of
drugs in keeping with the same principles adopted in the evaluation of
cost/benefit ratio.