Octreotide Treatment of Acromegaly

A Randomized, Multicenter Study

Abstract

Objective: To determine the effects of the somatostatin analog, octreotide acetate, in patients with acromegaly.

Design: Double-blind, randomized trial.

Setting: Fourteen university-affiliated medical centers.

Patients: One hundred fifteen acromegalic patients, 70% of whom had persistent disease after pituitary surgery or radiotherapy.

Intervention: Subcutaneous octreotide, 100 µg, or placebo every 8 hours for 4 weeks. Four weeks after the end of treatment, patients were randomized to receive 100 or 250 µg octreotide subcutaneously every 8 hours for 6 months.

Results: After 2 weeks of treatment, a single 100-µg injection reduced mean serum growth hormone (GH) to 30% of the pretreatment concentration within 2 hours. The integrated mean GH level was reduced over 8 hours from 39 ± 11 µg/L to 9 ± 2 µg/L (P < 0.001). Mean plasma insulin-like growth factor-1 (IGF-1) was reduced from 5100 µ 400 U/L to 2400 ± 400 U/L (P < 0.001). After 6 months, the mean GH was reduced from 39 ± 13 to 15 ± 4 µg/L by 300 µg of octreotide and from 29 ± 5 µg/L to 9 ± 2 µg/L by 750 µg of octreotide daily. The mean IGF-1 concentration was suppressed to 2100 ± 300 and 2500 ± 400 U/L after 300 and 750 µg octreotide, respectively. Integrated mean GH levels were reduced to less than 5 µg/L in 53% (95% Cl, 39% to 67%) and 49% (Cl, 35% to 63%), and IGF-1 levels were normal in 68% (Cl, 54% to 82%) and 55% (Cl, 40% to 70%) of patients receiving low- and high-dose octreotide, respectively. A substantial decrease in headache, amount of perspiration, joint pain, and finger circumference occurred in two thirds of the patients. The pituitary size was reduced in 19% (Cl, 5% to 33%) and 37% (Cl, 22% to 52%) of patients receiving 6 months of low- and high-dose octreotide, respectively. Ten percent and 13% of patients in each treatment group developed transient diarrhea; 10% and 14%, biliary sludge; and 6% and 18%, cholelithiasis, respectively.

Conclusion: Octreotide effectively decreased GH and IGF-1 concentrations in 53% and 68% of patients, respectively. The higher dose resulted in increased frequency of tumor shrinkage but added no biochemical or clinical benefit.

Article and Author Information

  • For current author affiliations and addresses, see end of text.

  • Grant Support: By Sandoz Research Institute.

  • Requests for Reprints: Shlomo Melmed, MD, B-131, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048.

  • Current Author Addresses: Dr. Ezzat: The Wellesley Hospital, E. K. Jones Building #536, 160 Wellesley Street East, Toronto, Ontario M4Y 1J3, Canada.

    Dr. Snyder: University of Pennsylvania School of Medicine, 36th St and Hamilton Walk, Philadelphia, PA 19104.

    Dr. Young: Department of Medicine, Mayo Clinic and Foundation, 200 First Street, SW, Rochester, MN 55905.

    Dr. Boyajy: Neuroendocrine Department, Sandoz Research Institute, Route 10, East Hanover, NJ 07936.

    Dr. Newman: Department of Medicine, New York University Medical Center/Manhattan Veterans Affairs hospital, 408 First Avenue, New York, NY 10010.

    Dr. Klibanski: Thyroid Unit/Department of Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, MA 02114.

    Dr. Molitch: Center for Endocrinology, Metabolism, and Nutrition, Northwestern University Medical School, 303 East Chicago Avenue. Chicago, IL 60611.

    Dr. Boyd: Division of Endocrinology, New England Medical Center, 750 Washington Street, Boston, MA 02111.

    Dr. Sheeler: Department of Endocrinology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195.

    Dr. Cook: University of Oregon School of Medicine, 3181 S.W. Sam Jackson Park Road, Portland, OR 97201.

    Dr. Malarkey: Department of Medicine, Ohio State University Medical Center, N-1106 Doan Hall, Columbus, OH 43210.

    Dr. Jackson: Department of Medicine, Brown University-Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903.

    Drs. Vance and Thorner: Department of Medicine, University of Virginia Medical Center, Box 511, Charlottesville, VA 22908.

    Dr. Barkan: Endocrinology Section, Veterans Affairs Medical Center, 2215 Fuller Road, Ann Arbor, MI 48105.

    Dr. Frohman: Division of Endocrinology & Metabolism, University of Cincinnati College of Medicine, Cincinnati, OH 45267.

    Dr. Melmed: Division of Endocrinology & Metabolism, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048.

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