Orthostatic hypotension (OH) causes approximately 80,000 hospitalizations per year in the US. Current treatment for OH includes midodrine and fludrocortisone. Although these medications have been
used for decades for treatment of OH, their relative effectiveness and safety is unknown. We compared incidence rates of hospitalizations for all causes, for congestive heart failure (CHF, safety outcome) and for syncope (effectiveness outcome) among users of midodrine compared to users of fludrocortisone (reference) in a retrospective cohort study of Tennessee Medicaid enrollees (1996-2008). Adjusted rate ratios were
calculated using propensity scores. We studied 636 patients initiating midodrine and 1066 patients initiating fludrocortisone. Incidence rates of all-cause hospitalizations for midodrine and fludrocortisone users were 1398 and 1515 per 1,000 person-years, respectively (adjusted incidence-rate ratio (aIRR) 0.88, 95% CI (0.75-1.03). The respective rates of syncope-related hospitalization were 129 and 129 per 1,000 person-years (aIRR: 0.90, 95% CI:0.60-1.36). Among 452 (27%) patients with prevalent CHF, the rates of all-cause hospitalization were 1786 and 2413 per 1000 person-years (aIRR: 0.66, 95% CI:0.47-0.87) (Figure), and the respective rates of CHF exacerbation-related hospitalizations were 285 and 297 per 1,000 person-years (aIRR: 0.60, 95% CI:0.34-1.06). Compared with fludrocortisone, users of midodrine had similar rates of all-cause and syncope-related hospitalizations. However, among patients with CHF, midodrine use was associated with a lower risk of hospitalization.