Faculty Bibliography

SMS 201-995, a long-acting somatostatin analog, was given as the initial treatment to an acromegalic patient. SMS 201-995 (200 micrograms, sc, three times daily) reduced, but did not normalize, serum GH levels. Complete and prolonged control of GH secretion was obtained with a 600-micrograms daily continuous sc infusion (CSI), and the patient was treated in this way for 6 months. Rapid improvement of clinical signs and symptoms of acromegaly occurred, as did major tumor shrinkage. The other pituitary functions did not change. After 6 months, the daily SMS 201-995 dose was progressively reduced; GH secretion remained suppressed. After 12 months of treatment, GH secretion was controlled with a CSI of 100 micrograms SMS 201-995 daily, but not with two daily sc 100-micrograms injections. Further significant reduction in tumor size occurred. We conclude that CSI of SMS 201-995 resulted in constant GH normalization and marked clinical and morphological improvement. This form of treatment should be considered as an alternative to ablative treatment of acromegaly.

Multiple sc injections of a long-acting somatostatin analogue (SMS 201-995) are currently used in the treatment of acromegaly. However, plasma GH concentration often reaches a pathological level (less than 5 micrograms/l) between two injections. In seven patients with active acromegaly we compared, in a short-term trial, the effect of SMS 201-995 administered by continuous sc infusion (50 micrograms and 100 micrograms a day) and by three sc injections (100 micrograms each). In six patients, plasma GH levels were significantly reduced regardless of the mode and dose of treatment (P less than 0.05). However, comparing diurnal profiles, 100 micrograms continuous sc infusion was more effective than discontinuous administration in reducing the number of GH levels above 5 micrograms/l (P less than 0.01). In two patients, continuous infusion was the only way to decrease all plasma GH values below 5 micrograms/l during the diurnal profile determination. Moreover, even when, in a long-term study, the dose of multiple injections was progressively increased to 500 micrograms three times a day, GH levels remained consistently elevated in one of these patients. Thus, in some acromegalic patients continuous sc injection seems currently the most efficient way of treatment with SMS 201-995.