Withdrawal of fall-risk-increasing drugs in older persons: Effect on tilt-table test outcomes

OBJECTIVES: To determine whether outcomes of tilt-table tests improved after withdrawal of fall-risk-increasing drugs (FRIDs). DESIGN: Prospective cohort study. SETTING: Geriatric outpatient clinic. PARTICIPANTS: Two hundred eleven new, consecutive outpatients, recruited from April 2003 until December 2004. MEASUREMENTS:Tilt-table testing was performed on all participants at baseline. Subsequently, FRIDs were withdrawn in all fallers in whom it was safely possible. At a mean follow-up of 6.7 months, tilt-table testing was repeated in 137 participants. Tilt-table testing addressed carotid sinus hypersensitivity (CSH), orthostatic hypotension (OH), and vasovagal collapse (VVC). Odds ratios (ORs) of tilt-table-test normalization according to withdrawal (discontinuation or dose reduction) of FRIDs were calculated using multivariate logistic regression analysis. RESULTS: After adjustment for confounders, the reduction of abnormal test outcomes (ORs) according to overall FRID withdrawal was 0.34 (95% confidence interval (CI)=0.06-1.86) for CSH, 0.35 (95% CI=0.13-0.99) for OH, and 0.27 (95% CI=0.02-3.31) for VVC. For the subgroup of cardiovascular FRIDs, the adjusted OR was 0.13 (95% CI=0.03-0.59) for CSH, 0.44 (95% CI=0.18-1.0) for OH, and 0.21 (95% CI=0.03-1.51) for VVC. CONCLUSION: OH improved significantly after withdrawal of FRIDs. Subgroup analysis of cardiovascular FRID withdrawal showed a significant reduction in OH and CSH. These results imply that FRID withdrawal can cause substantial improvement in cardiovascular homeostasis. Derangement of cardiovascular homeostasis may be an important mechanism by which FRID use results in falls.