Aging is often associated with multiple chronic conditions conducting increased consumption of drugs. Drug therapy is necessary for the treatment of many diseases. However, misuse of drugs, particularly linked to the potentially inappropriate prescribing and polypharmacy, increases the iatrogenic risks and can lead to adverse events such as falls, cognitive decline, increased use to the health system: hospital admissions, emergency room visits, and institutionalization. These problems are common since about 20% of emergency room use in elderly patients due to an adverse event related to drugs. Nearly 28% of adverse events related to drug prescriptions could be avoided.