Effect of inflammatory disease on plasma concentrations of three beta-adrenoceptor blocking agents

Plasma concentrations of three beta-adrenoceptor blocking agents, propranolol, oxprenolol, and metoprolol, have been measured over 24 h after a single oral dose in patients with active inflammatory disease, and in healthy subjects. After propranolol administration, peak plasma concentrations were approximately seven times higher in the patients; they remained significantly raised at all sampling times up to 10 h. With oxprenolol, peak plasma levels were about twice as high in the patients as in the healthy subjects and significantly raised on only two occasions. All plasma metoprolol values were within normal limits. These results did not run parallel with differences in metabolism between the three drugs, but did seem to relate to their degree of binding to plasma proteins (propranolol 93%, oxprenolol 80%, metoprolol 11%). Furthermore, it is known that propranolol binds to serum orosomucoid, an acute-phase reactant, which rises in inflammatory disease.