Repurposed existing drugs could serve as promising gerotherapeutic agents. However, their effectiveness in improving clinical outcomes among geriatric rehabilitation inpatients remains unclear. This study investigated the longitudinal observational association between potential gerotherapeutic drugs (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs), aspirin, metformin, beta-blockers, and bisphosphonates) and changes in physical function, readmission within 90 days, and mortality up to two years in geriatric rehabilitation inpatients from the RESORT cohort. The mean age of the patients was 82.6 (standard deviation 8.1) years, and 56 % were female (n = 1890). Repurposed drug use was not associated with changes in physical function or readmission. However, compared to patients who did not use any, those using metformin (Hazard ratio (HR) 0.54; 95 % confident interval (CI) 0.40 - 0.75), ACEi/ARBs (HR 0.71; 95 % CI 0.56 - 0.91), aspirin (HR 0.74; 95 % CI 0.57 - 0.96), and beta-blockers (HR 0.76; 95 % CI 0.58 - 0.98) had a significantly lower 1-year post-discharge mortality after adjusting for Charlson Comorbidity Index. Patients using three or more potential gerotherapeutic drugs had a significantly lower 1-year mortality (HR: 0.59, 95 % CI: 0.43-0.82) after comorbidity adjustment. Further investigations into the mechanisms of repurposed drugs, alone and in combination, in providing potential survival benefit among older adults are warranted.