Although
anticoagulants are beneficial in the prevention and management of many thromboembolic disorders, they can cause serious
bleeding. However, the risk of
anticoagulant-related
bleeding is not clearly defined for older patients, who are likely to benefit the most from
anticoagulant therapy. Older patients may be at increased risk for
anticoagulant-related
bleeding because of their increased incidence of
adverse drug reactions, increased prevalence of comorbidity and
polypharmacy and increased vascular and endothelial fragility. Furthermore, the
anticoagulant effect of
warfarin is increased in older patients. Therefore, it is important to determine whether or not
heparin-related and
warfarin-related
bleeding are more common in older patients. Most studies that have examined age as a risk factor for
heparin-related
bleeding have found
bleeding to be more frequent in older patients: patients 60 years and older were approximately 3 times as likely to develop
bleeding during
heparin therapy than were younger patients. Studies that have examined age as a risk factor for
warfarin-related
bleeding have found conflicting results. Seven studies, enrolling a total of 14,388 patients, found that older patients were approximately twice as likely to bleed during
warfarin therapy. In contrast, 7 studies, enrolling a total of 2940 patients, found no increase in the frequency of
warfarin-related
bleeding in older patients. These findings provide a basis for weighing the risks of
anticoagulant therapy and for making decisions about the use of
anticoagulants in older patients. These findings also indicate the potential value of methods to decrease the frequency of
anticoagulant-related
bleeding in older patients. Such methods include maintaining the
anticoagulant effect within the therapeutic range and recognising other modifiable factors, such as medication use, that may promote
bleeding.