XXXX : long-term treatment using a reduced dosing schedule.

@entity1 @entity137 @entity1165 @entity6237 @entity5126 @entity943
@entity6237 was initially prescribed at a dose of 200 mg twice daily, but after early @entity137 in @entity1 with @entity1165 ( @entity1165 ), the dosage was reduced to 100 mg twice daily. The effects of @entity6237 were studied in 40 @entity1 (29 @entity1 and 11 @entity1 , mean age 62 +/- 2 years, ejection fraction 45 +/- 3%) who underwent programmed electrical stimulation to determine the efficacy of @entity6237 in preventing @entity1165 chronically at the reduced dose. @entity1165 was induced in 21 @entity1 and nonsustained @entity1165 in 19. @entity6237 prevented @entity1165 induction in 26 @entity1 (65%). At a mean dose of 1.5 +/- 0.1 mg/kg, prolongation occurred in the effective refractory period of the first (280 +/- 5 vs 249 +/- 5 ms) and second (254 +/- 6 vs 209 +/- 9 ms) extrastimuli (p less than 0.01). In the @entity1 protected by @entity6237 , the effective refractory periods increased by a 17 +/- 2% and 21 +/- 3%, in contrast to only a 7 +/- 3% and 6 +/- 4% increase in the nonprotected group (p less than 0.05), despite a higher mean dose (1.9 +/- 0.1 vs 1.35 +/- 0.1 mg/kg). Twenty-one @entity1 were discharged on @entity6237 therapy, 100 mg twice daily, and were followed for a mean of 11 months. Sixteen @entity1 are alive and well, 1 died suddenly, 1 died from a noncardiac cause and 1 had a "breakthrough" @entity943 . Two were switched to @entity5126 therapy by their referring physicians, but were without problems while receiving @entity6237 .(ABSTRACT TRUNCATED AT 250 WORDS)
