Effect of Cimetidine on the Single-Dose PK of IV- Administered MNTX

Study Overview
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Brief Summary
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This open-label study assesses the single-dose pharmacokinetics of intravenously-administered MNTX in healthy adult male and female subjects in the absence of, and in the presence of, orally-administered cimetidine.

Official Title
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A Phase 1, Open-Label, Study of the Effect of Cimetidine, a Known Inhibitor of Active Renal Secretion, on the Single-Dose Pharmacokinetics of Intravenously-Administered Methylnaltrexone in Healthy Adults

Conditions
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Healthy Adult Subjects

Intervention / Treatment
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* Drug: methylnaltrexone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy males and females between the ages of 18 and 45 Subjects who are non-smokers Subjects with body weights with range of 154-220 lbs. Exclusion Criteria: Females who are pregnant or lactating Subjects with a history of any clinically significant disease or condition affecting a major organ system Subjects with ECG abnormalities Subjects who have tested positive for hepatitis B, hepatitis C or HIV Subjects who have had a diagnosis of alcohol or substance dependence with the past 12 months Subjects with positive urine results for drugs of abuse.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm 1<br>methylnaltrexone (MNTX) | Drug: methylnaltrexone<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak plasma concentration (Cmax) of MNTX prior to and following multi-dose cimetidine regimen | To assess the potential effects of cimetidine on the pharmacokinetics of MNTX | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the plasma concentration (AUC) of MNTX prior to and following a multi-dose cimetidine regimen | To assess the potential effects of cimetidine on the pharmacokinetics of MNTX | 7 days | 
| Half-life of MNTX prior to and following a multi-dose cimetidine regimen | To assess the potential effects of cimetidine on the pharmacokinetics of MNTX | 7 days | 
| Clearance (both total and renal)of MNTX prior to and following a multi-dose cimetidine regimen | To assess the potential effects of cimetidine on the pharmacokinetics of MNTX | 7 days | 
| Volume of distribution of MNTX prior to and following a multi-dose cimetidine regimen | To assess the potential effects of cimetidine on the pharmacokinetics of MNTX | 7 days | 
| Number of subject with adverse events as measured before, during, and after administration of cimetidine | To assess the potential effects of cimetidine on safety, and tolerability of MNTX | 7 days |