Objective: Antidopaminergic drugs may be useful in diabetic gastroparesis because the inhibitory activity of hyperglycemia on gastric motility seems to be related to dopamine receptor stimulation. For this reason, we evaluated the effect of levosulpiride on gastric emptying, dyspeptic symptoms, and metabolic parameters of insulin-treated diabetic patients.
Methods: Under double-blind conditions, 40 longstanding, insulin-treated dyspeptic patients with autonomic neuropathy and delayed gastric emptying were randomly submitted, with an interval of 15 days, to 4 wk of administration of both levosulpiride 25 mg t.i.d. and placebo according to a cross-over design. At the beginning of the study and after levosulpiride or placebo treatment, the gastric emptying time of a standard meal was measured ultrasonically; gastrointestinal symptom scores and glycaemic control were also evaluated.
Results: Levosulpiride reduced significantly (p < 0.001) the gastric emptying time from 416 +/- 58 to 322 +/- 63 min, whereas placebo did not change it consistently (396 +/- 58 vs 372 +/- 72 min). Symptoms improved significantly (p < 0.001) with levosulpiride compared with placebo. However, there was no significant correlation between the acceleration of gastric emptying and the symptomatological improvement. The reduction of mean plasma glycosylated hemoglobin concentrations after levosulpiride (7.3 +/- 1.9 vs 5.8 +/- 1.3) was not significantly different (p = not significant) compared with placebo (6.8 +/- .7 vs 6.1 +/- 1.4).
Conclusions: Our study first demonstrates that levosulpiride has an accelerating effect on the emptying of solids from the stomach of patients with diabetic gastroparesis. The drug is also effective in relieving upper gastrointestinal symptoms in patients whose gastric emptying times remain very slow. Our findings suggest, but do not prove, that better blood glucose control could be achieved with reduction of gastric emptying time; further trials are needed in this field.