Drug interactions in elderly patients

In the USA, adverse drug effects (ADE) are estimated to occur in 5% of the patients who take medication, resulting in 5 to 10% of all hospital referrals. Drug interactions are responsible for 3% of the hospital admissions (Jankel and Fitterman 1993). The ADE risk is particularly high in elderly patients (Müller-Oerlinghausen et al. 1999). The incidence of life-threatening drug interactions in patients with multiple illnesses has been shown to be 22% (Lipton et al. 1992). Elderly patients with depression have an increased rate of somatic co-morbidity: 52% suffer from hypertension, 52% from coronary heart disease, and 31% from movement-related degenerative illnesses (Förstl H., 1998). In addition to age-related physiological changes, disease-related hepatic and renal limitations are common and must be taken into consideration (e.g. Arzneimittelkommission der deutschen Ärzteschaft 2000). There are very few studies on the effects and consequences of drug interactions in elderly patients. Topics for investigation of primary importance have to be proposed.