Effect of Methylnaltrexone on GI Transit in Healthy Volunteers
Condition: Gastric Motility Disorder
Intervention: Methylnaltrexone only; Codeine only; Methylnaltrexone + codeine; Placebo + placebo
Intervention description: 0.30 mg/kg subcutaneous injection daily; 30 mg taken orally four times daily for 5 days; Methylnaltrexone 0.30 mg/kg by subcutaneous injection once daily and codeine 30 mg taken orally four times daily for 5 days; Placebo subcutaneous injection once daily and placebo taken orally four times daily for 5 days
Intervention MeSH terms: Naltrexone; Codeine; Methylnaltrexone
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 48.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Methylnaltrexone; Codeine; Gastrointestinal motility; Colonic transit

Summary:

      This is a single-center, randomized, double blind, placebo-controlled study evaluating the
      effects of placebo, codeine, methylnaltrexone and codeine with methylnaltrexone on
      gastrointestinal motility and colonic transit of solids in healthy human subjects.

      The hypotheses are:

        1. Methylnaltrexone administered subcutaneously enhances gastrointestinal motility with
           acceleration of overall colonic transit, and ascending colon emptying of solids in
           healthy humans.

        2. Methylnaltrexone significantly accelerates colonic transit that is delayed by codeine
    

Eligibility criteria:

        Inclusion Criteria

          -  Males and non-pregnant, non-breastfeeding females

          -  18-65 years old

          -  No functional GI disorders on the short Bowel Disease Questionnaire (BDQ)

          -  A BMI greater than 22.0

        Exclusion criteria

          -  Structural or metabolic diseases/conditions that affect the gastrointestinal system or
             functional gastrointestinal disorders. The short version of the Bowel Disease
             Questionnaire (BDQ) will be exclude functional GI disorders. More than three positive
             responses will exclude participation.

          -  Unable to withdraw from the following medications 48 hours prior to study entry:Any
             medication that alters GI transit including but not limited to laxatives, magnesium or
             aluminum-containing antacids, prokinetics, erythromycin, narcotics, anticholinergics,
             tricyclic antidepressants, SSRI and newer antidepressants; analgesic drugs including
             opiates, NSAID, COX 2 inhibitors (note : Tylenol is permitted); GABAergic agents and
             benzodiazepines. Note: Concomitant medications will be reviewed on a case by case
             basis by the study physicians.

          -  Subjects who are considered by the investigator to be alcoholics not in remission or
             known substance abusers. Alcohol must be avoided from seven days prior to beginning
             the study medication until the completion of the study.

          -  Subjects who have participated in another clinical study within the past 30 days.

          -  Clinical evidence (including physical exam and review of the medical history) of
             significant cardiovascular, respiratory, renal, hepatic, pulmonary, gastrointestinal,
             hematological, neurological, psychiatric, or other disease that interfere with the
             objectives of the study.