Falls among older people: relationship to medication use and orthostatic hypotension.

Objective: To assess the risk of falls attributable to medication use and orthostatic hypotension.

Design: Prospective cohort study.

Setting: Two self-care, apartment-style residential facilities in the Toronto area.

Participants: A total of 100 consecutive older volunteers (mean age = 83, range 62-96) who were independent in activities of daily living and able to stand unaided.

Measurements: Prescription medications used by each subject were documented at baseline. Blood pressure measurements were performed supine, immediately after standing, and after 5 minutes. Subjects reported falls weekly, by postcard, for a period of 1 year; nonreporters were contacted by telephone.

Results: Fifty-nine percent of subjects fell at least once during the 1-year follow-up. Antidepressant use was associated with an increase in the risk of experiencing one or more falls (RR = 1.6, P = .02). The use of other drug classes examined, including diuretics and sedative-hypnotics, was not associated with an increased risk of falling. Orthostatic hypotension was not predictive of falls. Surprisingly, there was an increase in the diastolic blood pressure of fallers, after 5 minutes, that was not seen in the nonfallers (3.3 vs -0.2 mm Hg, P = .05). Possible explanations for this previously unreported observation are explored.

Conclusion: Patients using antidepressants should be followed closely because the risk of falls is increased. Previously reported relationships between benzodiazepines and diuretics and falls are not supported by the present findings. Clinical detection of orthostatic hypotension is unlikely to be useful in predicting future risk of falling.