A double blind placebo controlled study was carried out in 40 subjects newly referred for treatment for
obesity to determine the effects of the new thermogenic beta
adrenoceptor agonist
BRL 26830A. The subjects were randomised to receive either
BRL 26830A, 200 mg daily for two weeks then 400 mg daily, or placebo for 18 weeks, and all were instructed to follow a 3.35 MJ diet that was low in fat and high in fibre.
Weight loss was 15.4 (SD 6.6) kg in subjects given
BRL 26830A compared with 10.0 (5.9) kg in those given placebo (p = 0.02). The relative
weight loss was 0.93 (0.39%) a week with
BRL 26830A and 0.61 (0.38)% with placebo (p = 0.02). Urinary excretion of
nitrogen was similar in both groups, whereas measurements of skinfold thickness indicated a 4.1 kg difference in the amount of fat lost, suggesting that
weight loss with
BRL 26830A was mainly from adipose and not lean tissue.
BRL 26830A had no effect on resting pulse rate or pressor effects on either diastolic or systolic blood pressure. No significant differences were found between the two groups in serum
cholesterol concentration, percentage of
high density lipoprotein cholesterol, plasma concentrations of
glucose and
insulin, the ratio of
glucose to
insulin, serum concentrations of
triiodothyronine and
thyroxine, and
creatinine clearance. Short term administration of
BRL 26830A to six subjects who had taken the
drug for 18 weeks showed that the expenditure of energy increased by 11.6% during the second hour after administration, which suggests that
BRL 26830A may enhance
weight loss thermogenically.
BRL 26830A may be a useful
drug in the treatment of
obesity.