Regional deposition of inhaled 11C-nicotine vapor in the human airway as visualized by positron emission tomography*
- 26 March 1995
- journal article
- research article
- Published by Wiley in Clinical Pharmacology & Therapeutics
- Vol. 57 (3), 309-317
- https://doi.org/10.1016/0009-9236(95)90156-6
Abstract
The deposition of 11C-nicotine in the respiratory tract from a nicotine vapor inhaler was studied by means of positron emission tomography (PET) in an intrasubject comparison of six healthy smokers using two modes of inhalation: one with shallow, frequent inhalations ("buccal mode") and one with deep inhalations ("pulmonary mode"). An average of 15% of the radioactivity was released from the vapor inhaler after 5 minutes of inhalation. Approximately 45% of the dose released was found in the oral cavity. A significant amount of radioactivity, 10%, was observed in the esophagus, suggesting transfer of a major fraction of the dose to the stomach. Only a minor fraction, 5%, was found in the lungs, followed by 2% in the bronchi and 1% in the trachea. The deposition in the oral cavity closely followed a linear pattern during the 5 minutes of inhalation and was followed by a rapid elimination from the oral cavity, with an average half-life of 18 minutes. Only 8% of the dose released remained in the oral cavity 45 minutes after the end of inhalation. On the other hand, the dose fraction of about 14% distributed into the body tissue compartment at the end of inhalation had risen to 60% at that late time point. No statistically or clinically important differences were observed between the buccal and the pulmonary mode of inhalation in either deposition pattern or elimination rates.Keywords
This publication has 6 references indexed in Scilit:
- Total and regional lung deposition of terbutaline sulphate inhaled via a pressurised MDI or via Turbuhaler®International Journal of Pharmaceutics, 1993
- Performance Characteristics of an Eight-Ring Whole Body PET ScannerJournal of Computer Assisted Tomography, 1990
- Pressurised aerosol deposition in the human lung with and without an "open" spacer device.Thorax, 1989
- Chapter 30 Attempts to visualize nicotinic receptors in the brain of monkey and man by positron emission tomographyPublished by Elsevier ,1989
- Nicotine Replacement in Smoking CessationJAMA, 1987
- Deposition of pressurised aerosols in the human respiratory tract.Thorax, 1980