title: Stereoselective pharmacokinetics and pharmacodynamics of anti-asthma agents.
abstract: OBJECTIVE
  To review the previously published studies on pharmacokinetics and pharmacodynamics of chiral drugs used in the treatment of asthma.
  
  
  METHODS
  Primary and review articles were identified with a MEDLINE search (1980-May 2001) and through secondary sources.
  
  
  METHODS
  All English-language studies and reviews obtained from the MEDLINE search pertaining to stereoselective pharmacokinetics and pharmacodynamics of chiral anti-asthma drugs were assessed.
  
  
  RESULTS
  Several anti-asthma drugs (e.g., beta(2)-adrenergic agonists, leukotriene modifiers) are chiral and marketed as racemates, which consist of equal proportions of 2 enantiomers. Significant stereoselectivity has also been reported in pharmacodynamics and pharmacokinetics of the beta(2)-agonists. The enantiomers of beta(2)-agonists in the R configuration are primarily responsible for the bronchodilating effects of the racemate. The plasma concentrations of the enantiomers of anti-asthma drugs may differ as a reflection of stereoselectivity in clearance, volume of distribution, and route of administration.
  
  
  CONCLUSIONS
  Stereoselectivity in the pharmacokinetics of anti-asthma drugs may complicate the relationship between dose and/or plasma concentration of racemic drug versus effect relationship. An appreciation of the stereoselective pharmacokinetics and pharmacodynamics of chiral anti-asthma drugs may optimize the use of these agents in asthmatic patients.
authors.affiliation: Department of Drug Metabolism and Pharmacology, TAP Pharmaceutical Product Inc., Lake Forest, IL 60045-4832, USA. majid.vakily@TAP.com
authors.forename: Majid
authors.initials: M
authors.lastname: Vakily
authors.forename: Reza
authors.initials: R
authors.lastname: Mehvar
authors.forename: Dion
authors.initials: D
authors.lastname: Brocks
mesh_terms: D000042:Absorption; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology*; D001682:Biological Availability; D006801:Humans; D016239:MEDLINE; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: D018927:Anti-Asthmatic Agents