[Infections in the elderly].
SPECIFIC EPIDEMIOLOGY: Respiratory infections predominate in the elderly; community acquired infections can be quite severe. In hospital, urinary infections predominate. Antibiotics must be prescribed without delay due to the less active immune response and the severe and rapid effect infection has on underlying diseases. Monitor renal function in order to adapt dosage and administration intervals to pharmacokinetic variations, notably concerning urinary excretion of many antibiotics; watch for drug interactions; beware of intolerance, more frequent than in younger patients. Wide interindividual variability suggests the need for clinical trials to study drug behavior, efficacy and tolerance in the elderly and to search for specific interaction or unexpected complications. The result would be better therapeutic options and dosages.