Dose Estimation for Studies of Acute Respiratory Effects

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00005362
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: May 2000
  Purpose

To modify and expand an existing pharmacokinetic model for nasal dose as well as to develop a new model to estimate tracheobronchial dose of an active agent for each subject in a study of acute respiratory health effects.


Condition
Lung Diseases

Study Type: Observational

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: September 1992
Estimated Study Completion Date: August 1995
Detailed Description:

BACKGROUND:

Epidemiologic analysis of acute, reversible respiratory health effects is uncommonly performed, yet these are important health outcomes because acute responses by the respiratory defense system appear to represent one end of the continuum toward progressive, chronic and potentially disabling physiologic changes. Repeatable epidemiologic studies of dose-response relationships necessitate accurate measures of 'dose'. However, in occupational and environmental settings, exposure to a toxin is seldom found at identical concentrations and/or particle sizes among persons with the same activity patterns. In addition, air concentration does not account for factors such as clearance or metabolism which may alter the biologically effective tissue dose. These factors cause the target tissue dose of the toxin to vary greatly despite exposure to similar air concentrations.

DESIGN NARRATIVE:

The results of these toxicokinetic models were individual measures of tissue dose used in a 2-stage epidemiologic analysis which placed special emphasis on the definition of individual dose-response curves for exposure to an irritant dust, sodium borate, and the reversible effects of peak expiratory flow and irritant symptoms. A primary advantage of the two stage epidemiologic approach was that it permitted particular attention to be focused on the factors which determined the sensitivity (threshold) and reactivity (slope) for an individual. The use of tissue dose estimates were also compared to simple exposure measurements in the epidemiologic analysis to evaluate the efficacy of using dosimetric methods in epidemiologic studies.

  Eligibility

Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria

No eligibility criteria

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

No Contacts or Locations Provided
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00005362     History of Changes
Other Study ID Numbers: 4249
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Lung Diseases
Respiratory Tract Diseases

ClinicalTrials.gov processed this record on August 26, 2014