The effects of the somatostatin analogue, octreotide, on postural hypotension, before and after food ingestion, in primary autonomic failure.

The effects of the somatostatin analogue, octreotide on postural hypotension have been compared with placebo, before and after food ingestion in two groups with primary autonomic failure; patients with pure autonomic failure, and patients with additional neurological involvement as part of multiple system atrophy. After placebo, supine blood pressure was unchanged, but after octreotide, it rose in both groups. Octreotide reduced pre-prandial postural and supine post-prandial hypotension in both pure autonomic failure and multiple system atrophy patients. Postural hypotension post-prandially was considerably worse after placebo; this was reduced after octreotide. Plasma noradrenaline and adrenaline levels remained unchanged. Plasma glucose levels rose higher and faster after placebo. Insulin levels were similar in both groups at rest, but rose higher in patients with pure autonomic failure after placebo. After octreotide, the insulin response in both groups was suppressed. We conclude that octreotide prevents post-prandial hypotension in both groups with primary autonomic failure and additionally reduces postural hypotension both before and after food ingestion. The greater rise in insulin levels in patients with pure autonomic failure suggests that insulin may be a contributing factor to the more severe post-prandial hypotension observed in this group of patients.