Xamoterol in severe congestive heart failure: long-term oral treatment, a double-blind randomised study

Twelve patients in severe congestive heart failure were given placebo, 100 mg xamoterol (Corwin) twice daily and 200 mg xamoterol twice daily, respectively, in 3 two-week periods in a double-blind randomised study. At the end of each treatment period the patients were evaluated. No differences were found between placebo and xamoterol in the following parameters: New York Heart Association function group index, heart volume, body weight, exercise duration on bicycle and treadmill, heart rate and systolic and diastolic blood pressure at rest. However, during exercise we found significantly lower heart rate and rate-pressure product during xamoterol treatment. This reduction is probably indicating occupation of beta-adrenoreceptors with concomitant reduced oxygen consumption during exercise.