Esmolol is a rapidly metabolized cardioselective
beta-adrenergic blocker that provides steady state beta-
adrenergic blockade when administered by continuous
intravenous infusion. To determine the efficacy of
esmolol in the management of
unstable angina, 23 patients with known
coronary artery disease, who averaged 3.7 +/- 2.7 daily episodes of
chest pain at rest, were randomized to receive either a continuous infusion of
esmolol (n = 12) or oral
propranolol (n = 11), as an adjunct to concomitant antianginal
therapy. Patients with systolic blood pressure less than 110 mm Hg, heart rate less than 60 beats/min or known
contraindications to beta blockade were excluded.
Esmolol was titrated in a step-wise fashion from 2 to 24 mg/min at 5-minute intervals up to a 30% reduction in heart rate and systolic blood pressure double-product. The
propranolol dose was increased every 6 hours by 50 to 100% to achieve a similar reduction in heart rate and blood pressure. When compared with their 24-hour baseline periods, both groups achieved a significant reduction in episodes of
chest pain, from 4.6 +/- 3.3 to 1.4 +/- 1.5 in the
esmolol group (p less than 0.02) and 2.6 +/- 1.4 to 1.0 +/- 1.5 in the
propranolol group (p less than 0.02) during the subsequent study period. The
cardiac event rate and incidence of
drug side effects were similar between the 2 groups; however, side effects seen with
esmolol did not require treatment after
drug discontinuation. Thus, maximally tolerated beta blockade is an effective
therapy for
unstable angina.(ABSTRACT TRUNCATED AT 250 WORDS)