抄録
β-Adrenoceptor blocking drugs (β-blockers) are widely used in the medical management of cardiovascular diseases. β-Blockers have two optical isomers and mainly the l-isomer has β-blocking activity, but many of the drugs are used as racemate for the clinical therapy. Studies on pharmacodynamic and pharmacokinetic relationships of β-blockers are important for clinical pharmacology. Because of low effective plasma concentrations (15-58 ng/ml), attempts have been made to develop sensitive, specific and simple immunological methods for the determination of β-blockers in plasma. Development of various types of immunoassay has been reported for dl-propranolol (PPL), l-PPL, acebutolol, diacetolol, oxprenolol, bunitrolol and befunolol. Each of these immunoassays appears to have sufficient sensitivity for the determination of plasma drug concentrations. Stereospecific radioimmunoassay for PPL isomers has revealed excellent correlation of β-blocking activity with plasma dl- and l-PPL concentrations, and longer half-life (T1/2β) for l-PPL in rabbits, but no difference in T1/2β between the isomers after single oral dose of dl-PPL in hyperthyroid patients. Although immunoassay for β-blocking drugs may sometimes encounter with problems of specificity, it has certainly advantages of sensitivity, simplicity of operation and stereospecificity.
