[Drug therapy in the old age. Drug effects in the elderly].

The frequency of multimorbidity in elderly patients may mislead the physician into practicing polypragmasy (polypharmacy), resulting in unpredictable drug interactions. Such interactions are a quite common cause of hospitalization in geriatric patients. Pharmacokinetics are often altered in the aged, and individualized medication should take into consideration not only the patient's age, liver and kidney function, but also the individual variability of hepatic metabolism and drug absorption from the gastrointestinal tract dictated by genetic polymorphism. Drug treatment in the elderly should always be carefully assessed as to its risks and benefits, and, where indicated, certain medications should be replaced by or omitted.