Pharmacological intervention in late life requires special care. Elderly patients are more susceptible to drug-induced adverse events. Particularly troublesome among older persons are peripheral and central anticholinergic effects such as constipation, urinary retention, delirium, and cognitive dysfunction; antihistaminergic effects such as sedation; and antiadrenergic effects such as postural hypotension. Sedation and orthostatic hypotension not only interfere with basic activities but also pose a significant safety risk to elderly patients because they can lead to falls and fractures. Increased susceptibility to adverse effects in elders may be a result of the pharmacokinetic and pharmacodynamic changes associated with aging, such as diminished glomerular filtration, changes in the density and activity of target receptors, reduced liver size and hepatic blood flow, and decreased cardiac output (Lotrich and Pollock 2005) (Table 26–1).