Study of Promethazine for Treatment of Diabetic Gastroparesis

Phase 2

Terminated

Brief Summary: 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.

Recruitment & Eligibility

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.

Arm && Interventions

Group	Intervention	Description
Promethazine	Promethazine	Promethazine 12.5 mg P.O. t.i.d. for 4 weeks
Sugar Pill	Sugar pill	Placebo P.O. t.i.d. for 4 weeks

Primary Outcome Measures

Name	Time	Method
Change in Patient-reported Symptoms as Measured by the Gastroparesis Cardinal Symptom Index Score (GCSI, 14) From Week 0 to Week 4.	4 weeks

Secondary Outcome Measures

Name	Time	Method
The Impact on Work Activity as Measured by the Work Productivity and Activity Impairment Questionnaire. (WPAI).	4 weeks
Occurrence of Adverse Events	4 weeks
Use of Rescue Medication	4 weeks	Frequency of use of the "rescue medication" meclizine