Drug metabolism pulmonary

Kehrer, J. P Witschi, H. Effects of drug metabolism inhibitors on butylated hydroxyto-luene-induced pulmonary toxicity in mice. Toxicol. Appl. Pharmacol 1980,53,333-342. 

Keywords Bronchial epithelium Pulmonary drug absorption Pulmonary metabolism Drug transport Permeability... 

Keywords Pneumocytes Pulmonary drug delivery Pulmonary metabolism, Alveolar epithelium... 

Foster KA, Oster CG, Mayer MM, Avery ML, Audus KL (1998) Characterization of the A549 cell line as a type II pulmonary epithelial cell model for drug metabolism. Exp Cell Res 243(2) 359-366... 

The alveolar-capillary membrane is normally very thin, has a huge surface area, and a large blood supply. Drugs given by this route, such as bronchodilators and pulmonary steroids, are rapidly absorbed into the bloodstream. This is also the route for administering the inhalational anaesthetics. DRUG METABOLISM AND EXCRETION... 

Some drugs are metabolized so readily that even marked reduction in liver function does not significantly prolong their action. However, cardiac disease, by limiting blood flow to the liver, may impair disposition of those drugs whose metabolism is flow-limited (Table 4-7). These drugs are so readily metabolized by the liver that hepatic clearance is essentially equal to liver blood flow. Pulmonary disease may also affect drug metabolism, as indicated by the impaired... 

Arif JM, Khan SG, Mahmood N, et al. 1994. Effect of coexposure to asbestos and kerosene soot on pulmonary drug-metabolizing enzyme system. Environ Health Perspect Suppl 102 181-183. 

Systemic availability of inhaled drugs may be inhibited by first-pass pulmonary metabolism. The lungs contain many drug metabolizing enzymes, including mixed function oxidases, monoamine oxidase, and esterases. 

A final, and not insignificant, consideration is the problem of drug metabolism in the respiratory tract. Although a large body of data indicates that pulmonary metabolism is generally relatively lower than hepatic metabolism [28], it is clear that nearly all of the drug metabolism activities found in the liver are present in the respiratory tract [1,25]. In addition, some respiratory tissues... 

Other Organs or Tissues of Potential Metabolic Importance The situation becomes much more complicated when tissues at the body s portals of entry are the focus of drug metabolism studies. Portals of entry include epithelial and other cells in various parts of the gut, cell layers of the skin, and cell linings in different parts of the bronchio-alveolar (pulmonary) system. Problems with these tissues and organs are multifaceted there are usually multiple... 

Taljanski W, Pierzynowski SG, Lundin DPD, Westrom BR, Eirefelt S, PodneslyJ, Dahlback M, Siwinska-Golebiowska H, and Karlsson BW. Pulmonary Delivery of Intratracheally Instilled and Aerosolized Cyclosporine A to Young and Adult Rats. Drug Metabolism and Disposition 1997 25(8) 917-920. 

PO. 50% bioavailability after oral dose. 75% protein bound, half-life=3 hrs, metabolites are active. Reduce dose in patients with renal dysfunction. AV node block, sick sinus syndrome, hypotension, pulmonary congestion. Beta-blockers and digoxin increase A-V conduction time. Diltiazem increases propranolol levels. Cimetidine and drugs metabolized by P-450 increase diltiazem levels. ... 

Sikic, B. I.. Mimnaugh. E. G., Litterest, C. L.. and Gram. T. E. The effects of ascorbic acid deficiency and repletion on pulmonary renal and hepatic drug metabolism in the guinea pig. Arch. Biochem. Biophys.. 779 663-671,1977. 

Drug metabolism, 259 Gastrointestinal agents, 56 Hallucinogens, 13 Hypnotics, 28 Muscle relaxants, 28 Neurotransmitters, 270 Parameters, physicochemical, 314 Pharmaceutics, 302 Pharmacokinetics, 302 Physicochemical parameters, 314 Pulmonary drugs, 67 Reactions in Medicinal Chemi stry, 291 Reproduction, 189 Sedatives, 28 Steroid hormones, 199 Steroids, 281 Stimulants, 13 Vasoconstrictors, 77 Vasodilators, 77... 

The inhalation route for administering drugs into the pulmonary system for treatment of respiratory diseases eliminates many bioavailability problems such as plasma binding and first-pass metabolism, which are encountered in parenteral or oral administration. Consequently, a small inhalation dose is adequate for achieving... 

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