Acute effects of octreotide, cabergoline and a combination of both drugs on GH secretion in acromegalic patients.
OBJECTIVE
The acute GH lowering effects of a single dose of either octreotide (OCT) or cabergoline (CAB), given alone and in combination, were studied in a series of 21 patients with acromegaly.


METHODS
Plasma GH was measured for 8 hours after a single subcutaneous injection of OCT (100 micrograms) and for 48 hours after a single oral dose of CAB (0.5 mg) in all patients. Fourteen patients, who did not suppress GH levels below 5 micrograms/L after either OCT or CAB given alone, also received a combination of both drugs (OCT 100 micrograms s.c. + CAB 0.5 mg p.o. 24 h before OCT).


RESULTS
GH levels were acutely suppressed by more than 50% in 15/21 cases after OCT alone and in 5/21 after CAB alone, respectively (P < 0.01). In the 14 patients who received the combined test, the magnitude of GH suppression was significantly higher than after OCT alone 4, 6 and 8 hours after OCT administration (P < 0.02). In patients with mixed GH/PRL-secreting tumors, the additive effect of OCT and CAB was observed at each time point.


CONCLUSIONS
These results suggest that combined therapy with OCT and CAB may be more effective in suppressing GH secretion than either compound given alone, especially in patients with GH/PRL-secreting adenomas.
Minniti
G
G
Endocrinologia I-II Clinica Medica, Università di Roma, La Sapienza, Italy.
Jaffrain-Rea
M L
ML
Baldelli
R
R
Ferretti
E
E
Caracciolo
B
B
Bultrini
A
A
Gulino
A
A
Tamburrano
G
G
D000172:Acromegaly / Q000097:blood / Q000188:drug therapy*; D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000077465:Cabergoline; D003627:Data Interpretation, Statistical; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D004873:Ergolines / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000187:drug effects* / Q000378:metabolism; D006728:Hormones / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
D018491:Dopamine Agonists; D004873:Ergolines; D006728:Hormones; D013006:Growth Hormone; D000077465:Cabergoline; D015282:Octreotide