MECHANISMS BY WHICH OCTREOTIDE AMELIORATES SYMPTOMS IN THE DUMPING SYNDROME

Octreotide reduces abdominal and vasomotor symptoms in dumping syndrom e by unknown mechanisms. Effects of octreotide (50 mu g) on symptoms, hemodynamic parameters and plasma glucose and insulin levels after glu cose meals were tested in double-blind, placebo-controlled, crossover fashion in eight patients with dumping syndrome. Gastric scintigraphy tested whether octreotide reduces symptoms by slowing gastric emptying . Octreotide reduced diarrhea, lightheadedness and palpitations after 75 g of glucose, compared with placebo (P < .001). Orthostatic pulse i ncreases after glucose decreased from 36 +/- 6 beats/min after placebo to 9 +/- 5 beats/min after octreotide (P < .05), and standing blood p ressure decreases after glucose were abolished (P < .05), but octreoti de had no effect on increases in hematocrit or plasma osmolarity after glucose. Late hypoglycemia was prevented by octreotide, and peak fed insulin levels were reduced from 87 +/- 15 to 26 +/- 9 mu U/ml after o ctreotide (P < .05). Times to maximal plasma glucose levels after meal s were prolonged from 28 +/- 4 to 78 +/- 6 min after octreotide (P < . 05). Octreotide had no effect on gastric emptying of liquids or solids . In conclusion, amelioration of dumping symptoms by octreotide is ass ociated with reduced orthostasis, which is not a consequence of preven tion of hemoconcentration. Prevention of late hypoglycemia may be due to blunted insulin release. Octreotide does not reverse rapid gastric emptying, indicating a limited role for this purported mechanism of ac tion.