Beneficial effect of dose escalation of octreotide-LAR as first-line therapy in patients with acromegaly.
OBJECTIVE
To evaluate the efficacy of dose escalation of Octreotide-long-acting repeatable (LAR) up to 40 mg/month we studied 56 newly diagnosed patients with acromegaly (24 women, 32 men; age 20-82 years).


METHODS
Analytical, observational, open and prospective.


METHODS
Three months after LAR treatment beginning with a dose of 20 mg /q28d (every 28 days), 24 patients maintained the same dose (Group A), while 32 required a dose of 30 mg/q28d (Group B). The dose was further increased to 40 mg/q28d in 17 out of the 32 patients of Group B for another 12 months (Group C).


RESULTS
After 24 months, serum GH and IGF-I levels decreased by 93.1 +/- 8.6% (95% confidence limit (CL) 90.8-95.4%) and 62.7 +/- 13.4% (95% CL 59.1-66.3%) respectively. Control of GH and IGF-I levels was achieved in 45 patients (80.3%). Tumor shrinkage after 12 months was 49.8 +/- 23%; the relative tumor shrinkage during the second 12 months of treatment was 35.3 +/- 13.1% and overall tumor volume was 68.1 +/- 16.5% (95% CL 63.7-72.5%). Glucose tolerance impaired in eight patients (14.3%): four in Group A and four in Group C (16.7% vs 36.4%, P=0.39). The final dose was predicted by the patient's age at diagnosis (t=-2.2; P=0.032) and baseline tumor volume (t=2.1; P=0.043).


CONCLUSIONS
An increase of the LAR dose up to 40 mg/q28d in patients resistant to 30 mg/q28d is followed by greater suppression of GH and IGF-I levels and tumor shrinkage without further significant impairment of glucose tolerance when compared with lower doses. These results suggest that a new dosage schedule of 40 mg every 28 days is applied in patients with acromegaly mostly of young age and with bigger tumors who are likely to be poorly responsive to standard doses of Octreotide-LAR.
Colao
Annamaria
A
Section of Endocrinology, Department of Molecular and Clinical Endocrinology and Oncology, University Federico II of Naples, via S Pansini 5, 80131 Naples, Italy. colao@unina.it
Pivonello
Rosario
R
Auriemma
Renata S
RS
Galdiero
Mariano
M
Savastano
Silvia
S
Lombardi
Gaetano
G
D000172:Acromegaly / Q000097:blood / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000008:administration & dosage* / Q000737:chemistry; D011446:Prospective Studies
D003692:Delayed-Action Preparations; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D015282:Octreotide