Pharmacokinetics of Naltrexone Following Intravenous and Oral Routes of Administration in Healthy Volunteers

Biological Availability Clinical Trial

Official title: Pharmacokinetics of Naltrexone Hydrochloride (HCl) Following Intravenous (i.v.) and Oral Routes of Administration in Healthy Subjects

Status Completed

Clinical Trial Summary

The purpose of the study is to compare the pharmacokinetics of naltrexone following i.v. and oral administration in healthy volunteers, and to assess the bioavailability of naltrexone following oral administration. Moreover, safety is assessed.

Clinical Trial Description

Naltrexone blocks the effects of opioid (morphine-like) drugs by competitive binding at the opioid receptors in the brain. Naltrexone does not possess morphine-like properties and exhibits minimal pharmacologic activity. Naltrexone is marketed as an oral tablet. A wide range of oral bioavailability values have been reported for naltrexone. The wide range in oral bioavailability of naltrexone appears to be due to differences in assay specificity and the method of estimation of bioavailability (use of total drug, free drug, or urinary excretion data rather than plasma level). This was a single-center, randomized (study drug assigned by chance), open-label, 2-treatment, 2-period crossover study in healthy volunteers. Healthy volunteers were randomly assigned to 1 of 2 treatment sequences (AB or BA) with a washout period of 6 to 14 days between treatments. The washout period commenced the day of dosing, after drug administration. Blood samples for determination of blood naltrexone levels were collected at scheduled time points from the arm opposite to the 1 selected for naltrexone i.v. administration. Pulse, blood pressure, breathing rate, body temperature were measured at the times listed in the study schema. Healthy volunteers remained at the research facility for blood sample collection periods and were monitored for adverse events throughout the treatment periods.

Treatment A: 1 mg naltrexone HCl administered i.v. over 15 minutes (naltrexone i.v.). Treatment B: 50 mg naltrexone HCl administered orally (naltrexone oral). ;

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacokinetics Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Biological Availability

• NCT number: NCT00714584
• Study type: Interventional
• Source: Alza Corporation, DE, USA
• Status: Completed
• Phase: Phase 1
• Start date: May 2003
• Completion date: June 2003