Role of a long-acting somatostatin analogue (SMS 201-995) in the treatment of acromegaly.

The beneficial effect of the long-acting analogue of somatostatin SMS 201-995 in the treatment of acromegaly is described in three cases, and current published experience is reviewed. A total of 64 patients from 10 series have received the drug from one to 25 months, usually in doses of 50-150 micrograms every eight hours by subcutaneous injection. Clinical and chemical improvement was observed in the majority of subjects but normal 24-hour serum growth hormone levels were achieved in no more than 35 percent of this group and possibly less. We have found that higher doses, up to 1,500 micrograms per day, which have generally been free of side effects, are sometimes required to normalize growth hormone secretion. A reduction of up to 33 percent in pituitary tumor size has been reported in more than half of the 27 cases studied from four groups. Clinically important side effects are infrequent, but diarrhea, usually transient, occurred in about 13 percent, with frank steatorrhea in 2 to 6 percent of cases. Alteration in carbohydrate metabolism, such as transient glucose intolerance at the start of therapy in non-diabetic acromegalic patients, and increased sensitivity to insulin or oral hypoglycemic agents in diabetic acromegalic patients, is common. Overall, SMS 201-995 appears to be a valuable new agent for the treatment of acromegaly, but long-term safety needs to be established.