Adverse drug reactions. An overview of special considerations in the management of the elderly patient.

The incidence of adverse drug reactions increases with aging, and the elderly are more likely to suffer serious or fatal reactions. Thus, morbidity and mortality are considerable in old patients, with 15% of those in hospital suffering a reaction, and many admitted as a consequence of one. The greater propensity of older patients for adverse drug reactions largely reflects the prescription of drugs to them, although over-the-counter purchases must also play a part. The elderly take more drugs per se (which is a reflection of multiple pathology), and more drugs with a narrow therapeutic index associated with a high risk of dangerous adverse reactions and drug interactions. They also have a reduced ability to withstand any reactions due to concomitant disease, and an altered pharmacokinetic and -dynamic response which tends to increase drug effects. The recommendation must be to use fewer drugs in older patients, perhaps trying alternative medicine first in nonacute conditions. Starting doses can often be reduced in the elderly, and clinical and therapeutic monitoring of effect is mandatory. The use of diuretics, antihypertensives, anti-Parkinsonian drugs and anticoagulants emphasise these points, and is discussed in detail together with digoxin, analgesics and nonsteroidal anti-inflammatory drugs. Clear guidelines are given for the use of each of these classes of drug.