Theophylline in the prevention of vasovagal syncope recurrences.

Abstract

Objectives: The present work aimed to study the efficacy and patient compliance of oral theophylline treatment in the prevention of vasovagal syncope recurrences.

Background: High blood adenosine may trigger vasovagal syncope. Theophylline is an adenosine receptor antagonist.

Methods: In 44 patients with vasovagal syncope (8 men and 34 women, age 46.4±3.2 years) with an average 4.8±0.74 syncopal episodes (range 1-20, median 4,5 episodes) oral theophylline therapy was started with dose 2x100/200 mg, which was further increased if necessary. All patients were treated by non-pharmacological measures which were not effective. Patients were followed in regular intervals on an outpatient basis in 6-month intervals.

Results: After the start of treatment patients were followed for the mean of 17.1±2.1 months (2-51 months, median 12 months). The total number of syncopal episodes decreased from 4.8±0.74 to 1.73±0.45 (p=0.0006). The occurrence of syncopal episodes per year decreased from 4.07±0.80/year to 1.50±0.54 /year during the treatment period (p=0.001). After a gradual increase in theophylline dosage, in 34 patients no syncopal recurrences were observed. In 10 persons syncopal recurrences persisted despite treatment. Side effects leading to discontinuation of treatment were present in 14 patients - gastrointestinal intolerance (7 patients), palpitations (6 patients) and headache (3 patients).

Conclusion: The addition of oral theophylline preparation to non-pharmacological treatment led to a marked reduction of syncopal recurrence in patients with vasovagal syncope. About one-third of study subjects discontinued therapy because of side effects (Tab. 2, Fig. 4, Ref. 22). Text in PDF www.elis.sk Keywords: heophylline, adenosine, vasovagal syncope, treatment.