Dynamics of the acute effects of octreotide, bromocriptine and both drugs in combination on growth hormone secretion in acromegaly.
The separate and combined GH-lowering effects of single doses of octreotide and bromocriptine were assessed in 51 acromegalic patients on 4 occasions each 2 days apart. Patients received sequentially: placebo sc (N = 51), 50 micrograms octreotide sc (N = 51), 2.5 mg bromocriptine po (N = 40) or a combination of both drugs (N = 25). With octreotide, in 28 patients (55%) GH levels were suppressed to less than 5 micrograms/l and 39 of them (76.5%) had a 50% or greater decrease of their basal GH level from 2 to 6 h. During bromocriptine, GH values were suppressed to below 5 micrograms/l in 11 patients (27.5%) and reduced by 50% or more in 21 (52.5%). The combination of both drugs acutely suppressed GH levels to less than 2 micrograms/l in 32%, to less than 5 micrograms/l in 56%, and by more than 50% in 84% of patients. Octreotide produced a stronger and faster suppression of GH levels than bromocriptine in most patients. The combination of both drugs had an additive effect on the lowering of GH levels, especially between 7 and 10 h after drug administration. These results suggest that chronic therapy with a combination of both drugs may be as effective as therapy with higher doses of either compound alone. Albeit transient, octreotide caused a rapid near total suppression of insulin release in the morning, 15 to 45 min after administration. Postprandial glucose rise, between 2 and 3.5 h after breakfast was significantly higher during octreotide than on the control day.
Wagenaar
A H
AH
Department of Neuroendocrinology, Clinical Research, Sandoz Pharma Ltd, Basle, Switzerland.
Harris
A G
AG
van der Lely
A J
AJ
Lamberts
S W
SW
D000172:Acromegaly / Q000097:blood* / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001971:Bromocriptine / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*
D001786:Blood Glucose; D007328:Insulin; D001971:Bromocriptine; D013006:Growth Hormone; D015282:Octreotide