Diabetic Gastroparesis | Study of Promethazine for Treatment of Diabetic Gastroparesis

Diabetic Gastroparesis research study

What is the primary objective of this study?

Adult diabetic patients (ages 18-65) with gastric emptying scintigraphy-confirmed delayed gastric emptying will be recruited to participate in the study. Using double-blinded methodology, study participants will be randomly assigned to one of two treatment arms: promethazine 12.5 mg three times daily for 28 days or placebo three times daily for 28 days. The primary outcome will be the change in gastroparesis symptom severity, as measured by the Gastroparesis Cardinal Symptom Index (GCSI) at four weeks compared to baseline. Participants will be seen for a clinic evaluation at weeks 0, 2 and 4, during which symptom scores, adverse events and treatment compliance will be assessed. It is hypothesized promethazine treatment will be superior to placebo in improving symptoms of gastroparesis.

Who is eligible to participate?

Inclusion Criteria: - adult patients 18-65 years of age - clinical diagnosis of diabetic gastroparesis. - EGD without evidence of gastric outlet obstruction within the past five years - gastric emptying scintigraphy test demonstrating >10% solid food retention at 4 hours within the past three years. Exclusion Criteria: - the inability or unwillingness to provide informed consent - currently pregnant or breast feeding - prior placement of a gastric stimulator - pyloric botulinum toxin injection within the past 12 months - prior gastric surgery - history of a connective tissue disorder - use of narcotic medication within the past four weeks - hemoglobin A1C >12 mg/dL within the past 3 months - current or recent (within past 4 weeks) use of promethazine, metoclopramide or domperidone - hypersensitivity or prior adverse reaction to promethazine - concomitant use of phenothiazines (i.e. prochlorperazine, chlorpromazine) or other agents likely to increase extrapyramidal reactions - concomitant use of tiotropium or ipratropium - narrow angle glaucoma - urinary retention - Parkinson's disease - significant psychiatric disease - history of seizure.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Diabetic Gastroparesis

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.


Drug:Sugar pill

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

PromethazinePromethazine 12.5 mg P.O. t.i.d. for 4 weeks

Sugar PillPlacebo P.O. t.i.d. for 4 weeks

Study Status


Start Date: July 2014

Completed Date: May 14, 2015

Phase: Phase 2

Type: Interventional


Primary Outcome: Change in Patient-reported Symptoms as Measured by the Gastroparesis Cardinal Symptom Index Score (GCSI, 14) From Week 0 to Week 4.

Secondary Outcome: Occurrence of Adverse Events

Study sponsors, principal investigator, and references

Principal Investigator: Brian E. Lacy, MD

Lead Sponsor: Dartmouth-Hitchcock Medical Center

Collaborator: American College of Gastroenterology

More information:

Cherian D, Parkman HP. Nausea and vomiting in diabetic and idiopathic gastroparesis. Neurogastroenterol Motil. 2012 Mar;24(3):217-22, e103. doi: 10.1111/j.1365-2982.2011.01828.x. Epub 2011 Nov 27.

Discuss Promethazine