Midodrine hydrochloride in the management of older adults with neurocardiogenic syncope and orthostatic hypotension: A prospective observational study

BackgroundMidodrine hydrochloride has been shown to be effective in the management of syncope in adults with reflex syncope, orthostatic hypotension and orthostatic intolerance syndromes; however, its use, tolerability and side effects have not been monitored specifically in the older old, particularly not over a prolonged period of time.ObjectivesWe aim to document changes in patients’ symptoms, drug dosages employed and adverse drug reactions to midodrine therapy in older adults with a diagnosis of neurocardiogenic syncope assessed and managed at a specialist falls and syncope outpatient unit.MethodsProspective observational study of 135 consecutive subjects with a mean age of 84 years started on midodrine after comprehensive geriatric assessment, structured falls evaluation, positive tilt table testing (TT) or a mixed/vasodepressor response to carotid sinus massage (CSM).ResultsNinety-seven individuals (71%) commenced on midodrine treatment and followed up for a mean of 2.7 years, reported either significant improvement or abolition of symptoms across all TT/CSM diagnosis. Forty-nine percent of individuals achieved sustained clinical improvement after an initial dosage of 2.5 mg three times per day and only four patients required dosages above 7.5 mg three times daily. One hundred and one individuals (75%) continued midodrine until the end of the monitoring period, and although 19 subjects developed adverse drug reactions, most were minor and only six resulted in drug withdrawal.ConclusionsMidodrine hydrochloride appears to be safe and well tolerated in older adults and should be considered, independent of age, in the management of patients with symptomatic orthostatic hypotension, vasovagal syncope and vasodepressor or mixed carotid sinus syndrome. This observation requires further confirmation by larger multicenter randomised control studies.