Midodrine hydrochloride in the treatment of vasovagal syncope.

Therapy of vasovagal syncope is still a subject of debate. Various pharmacotherapies were proposed. However, they are often not tolerated or ineffective. The purpose of this prospective, nonrandomized study was to evaluate the usefulness of alpha-agonist midodrine hydrochloride in the treatment of vasovagal syncope. Forty-one patients (mean age 34 years, 18 men) with history of recurrent syncope and positivity of head-up tilt testing were included (28 patients with type 1, 10 patients with type 2, 3 patients with type 3 according to VASIS classification). In all patients oral therapy with midodrine was started. Initial dose was 2.5 mg two times daily. When necessary, the dose was increased to 5 mg two times daily. Efficacy of treatment was assessed by repeated head-up tilt testing after 1-2 weeks of therapy and by long-term follow-up. After midodrine hydrochloride treatment, 39 of 41 patients (95%) had no inducible presyncope or syncope on repeated tilt table testing. Effective dose was 2.5 mg two times daily in 25 patients and 5 mg two times daily in 16 patients. During a mean follow-up period 19+/-9 months, 38 of 39 patients (97%) with negative repeated tilt table test remained free of syncope recurrence.