Effects of inflammatory disease on plasma oxprenolol concentrations

When single oral doses of oxprenolol were given to three healthy subjects on three separate occasions under standardised conditions the plasma concentration-time curves for each subject were closely similar. In two of the subjects, however, a mild illness led to a dramatic, temporary increase in the peak plasma concentration and area under the plasma concentration-time curve (AUC). This effect of inflammatory disease was confirmed by comparing a group of patients with an erythrocyte sedimentation rate (ESR) of over 20 mm in the first hour with a group whose ESR was below this value. The mean peak plasma concentration and AUC were significantly higher in the group with a raised ESR. This may be related to altered concentrations of one of the acute-phase proteins. Thus it is concluded that plasma oxprenolol concentrations are raised in inflammatory disease, but further work is needed to determine the mechanism of this increase.