Introduction

The most frequent medical intervention performed by a doctor is the writing of a prescription. Because chronic illness increases with advancing age, older people are more likely to have conditions that require drug treatment. Advanced age, frailty, and increased use of drugs are all factors that contribute to a patient's risk of developing a drug related problem. As many as 28% of hospital admissions in the United States of older people are as a result of drug related problems,1 up to 70% of which are attributed to adverse reactions to drugs.1 Creating optimal drug regimens that meet the complex needs of elderly people requires thought and careful planning.

Inappropriate prescribing is expensive. In a recent study the costs of preventable adverse drug events—namely, injury resulting from a drug related medical intervention—occurring during a stay in hospital were estimated to be $2.8m (£1.75) annually in two large American teaching hospitals.2 The national cost of managing the consequences of inappropriate prescribing remains uncertain. One estimate has put the annual cost of drug related morbidity and mortality in outpatient clinics at $76.6bn.3 Drug related morbidity and mortality is an important area to target both to improve the quality of medical care for elderly people and to reduce the costs of health care for this population.

A prescriber can do little to modify age related physiological changes in trying to minimise the likelihood that an older person will develop an adverse drug reaction. However, when assessing a patient who is already taking drugs, a doctor should always consider the development of any new signs and symptoms as a possible consequence of the patient's drug treatment. This article will focus on an under-recognised, and largely preventable drug related problem that we have termed the “prescribing cascade.” 4 The prescribing cascade begins …