[Polypharmacy: interaction and adverse reactions in the use of drugs by elderly people].

The article has for objective to reflect on the polypharmacy of the aged with emphasis in the adverse drug reactions and the drug-drug interactions. The vulnerability of the elderly to the problems related from the use as of drugs is pretty upswing, the one to in case that must the complexity of the problems clinical, at the must as of need pharmacotherapeutic interventions, and to the update pharmacokinetic and pharmacodynamic changes inherent to the aging. In this way, to rationalize the drugs utilization and to avoid the injury related to the polypharmacy will be, doubtless, one of the biggest challenges for public health in this century.