Usefulness of Fluoxetine Hydrochloride for Prevention of Resistant Upright Tilt Induced Syncope

Abstract

Recurrent vasovagally mediated episodes of hypotension and bradycardia are a common cause of recurrent syncope that can be identified by head-upright tilt table testing. Although the use of beta blockers, transdermal scopolamine, disopyramide, and fludrocortisone may be helpful in preventing further episodes, some patients are intolerant of or respond poorly to each of these agents. Following anecdotal observations, we investigated the utility of fluoxetine (a serotonin re-uptake antagonist) in preventing head-upright tilt induced hypotension/bradycardia in patients unresponsive to or intolerant of standard therapy. Sixteen patients (7 men and 9 women, mean age 42 +/- 21 years) with recurrent syncope and positive head-upright tilt studies (refractory to normal therapy) were placed on fluoxetine and restudied 5-6 weeks afterward. Three patients were intolerant of the medication. Of the 13 patients who underwent repeat tilt studies, seven patients (53% of the patients retested or 44% of the total group) were rendered tilt table negative, and, over a mean follow-up period of 19 +/- 9 months, have remained asymptomatic. We conclude that fluoxetine may be an effective therapy in patients with recurrent vasovagally mediated syncope refractory to other forms of therapy.

Guidelines on management (diagnosis and treatment) of syncope

“…In general, while the results have been satisfactory in uncontrolled trials or shortterm controlled trials [275][276][277][278][279][280][281][282][283][284][285][286][287][288] with few exceptions [132,289] , several long-term placebo-controlled prospective trials have been unable to show a benefit of the active drug over placebo [133,134,[290][291][292][293][294] with one exception [295] . In vasovagal syncope beta-blockers, owing to their negative inotropic effect, have been supposed to lessen the degree of mechanoreceptor activation associated with an abrupt fall in venous return and block the effects of elevated circulating adrenaline, but this theory has not been supported by facts.…”

Syncope

“…Other selective serotonin reuptake inhibitors such as fluoxetine and sertraline are less well tolerated when used for vasovagal syncope. 94,96 Clinical experience has not replicated the dramatic results of the one randomized trial.…”

Serotonin Reuptake Inhibitor (Paxil) Does Not Prevent the Vasovagal Reaction Associated With Carotid Sinus Massage and/or Lower Body Negative Pressure in Healthy Volunteers

“…[5][6][7] Recently, Girolamo et al 5 demonstrated the effectiveness of paroxetine hydrochloride (Paxil, SmithKline Beecham) in reducing tilt and recurrent syncope in patients with refractory NMS. The postulated mechanism of action is an increase in central serotonin levels, which results in down-regulation of serotonin receptors, and thus attenuates any short-term, sudden shifts in central serotonin levels.…”