Preoperative Octreotide Treatment of Acromegaly

Preoperative Octreotide Treatment of Patients With Growth Hormone Producing Pituitary Adenomas

The purpose of this study is to investigate whether 6 months preoperative treatment with the somatostatin analogue octreotide improves the surgical outcome in patients with acromegaly.

After a baseline evaluation, patients are randomized separately for each study center in blocks of four directly to transsphenoidal surgery or to 6-month preoperative treatment with octreotide.

To reduce the risk of gastrointestinal adverse effects in the pretreatment group, octreotide is initiated at a dose of 50 µg sc three times a day for the 1st week and 100 µg sc three times a day for the 2nd week. From the 3rd week on, the patients receive octreotide LAR (Novartis International AG, Basel, Switzerland) 20 mg im every 28th day for 6 months. Patients receive transsphenoidal surgery within 28 d of the last injection. If surgery are delayed, an extra octreotide LAR injection is given before surgery.

Inclusion Criteria:

• GH nadir during a standard 75 g OGTT >= 5.0 mmol/L.
• Pituitary tumor by MRI-scan.

Exclusion Criteria:

• Immediate surgery indicated by usual clinical criteria.
• Pregnant.
• Known adverse effects of octreotide.
• Unfit for participation by any other reason.