Objectives: The elderly population in Iran is increasing and they likely use more drugs than any other age groups. The older adults are often suffered from chronic conditions that may require long-term medical treatment, and likely involve multiple drug therapies and may consume up to four times as many defined daily doses as the rest of the population. Therefore we examined the drug used pattern in people of 55 years age and older and its association with their demographic characteristics.

Methods & Materials: This study is cross-sectional. Information on the intake of all drugs was collected from 400 subjects of 55 years age and older residents in Tehran, randomly selected and interviewed at home by a brief questionnaire regarding personal, social and medical factors.

Results: The average number daily drugs used were 3.4±1.9 different drugs, 40% used 4 or more drugs daily, %35 visited several physicians for the same illness, and 19% experienced adverse drug reactions. The most commonly used drugs were ASA, Atenolol, and propranolol. Pattern of drug consumption between the two genders, different age groups, level of educations and economic status except for ASA were similar. The most used drug categories were cardiovascular drugs (%35), central nervous system drugs (%25) and hormones (%9). The most common sources of drug information were physician’s %86.

Conclusion: Patient education, physicians and pharmacists' education in feedback systems and regulatory intervention can improve the drug prescribing and usage in older persons.