Our Long Term Experimentation with Slow Release Octreotide Therapy in our Acromegalic Patients and Anusual Side Effect: Hypoglycemia

Abstract

Octretide is a somatostatin analog that inhibits GH and currently has been effectively used in acromegalic patients. The objective of present study was to establish the long term effects of somatostatin: the clinical response, tumor size, GH, IGF-I concentrations and side effects. We also report a severe hypoglycemic attack in an acromegalic patient whose GH levels were within the normal limits.

12 patients with acromegaly [8 females (median age 40.2 +/- 6,4 yr), 4 males (52,5 +/- 7,2 yr)] were prospectively evaluated after a mean follow - up of 24,8 +/- 17 months (6-58 months) on sandostatin -LAR.

Mean GH decreased from 18, 3 +/- 11, 1 ng/ml to 5, 8 +/- 4,3ng/ml (p<0,001). GH reductions to less than 5.0 ng/mL were observed in 9 of the 12 patients (75%) and reductions to less than 2ng/mL were observed in 2 of them (16, 6%). Mean IGF-1 concentration was 1730 +/- 1301 ng/mL at the beginning of the study and decreased to 592 +/- 455,1 ng/mL. The difference was statistically significant (p<0,01). Baseline MRI showed macro-adenomas in six patients. No increase in tumor size was observed in any patient. Tumor size decreased from 3320 +/- 4539 mm3 to 2581 +/- 3840 mm3 (p=0, 08). MRI showed empty sella in three patients. Clinical symptoms improved remarkably in all patients. Only one patient could not continue therapy because of severe hypoglycemic attacks after 20 months of sandostatin therapy.

Monthly injections of sandostatin LAR were effective to reduce GH and IGF-I levels in patients with active acromegaly. In the long term period this drug is well tolareted but we suggest that hypoglycemia should be kept in mind even if the GH levels are within the normal limits.