Interpatient variability in response to a given dose of meperidine, a synthetic opiate analgesic, may be partially explained by variability in plasma protein binding. Alpha 1-acid glycoprotein (AAG), a plasma protein that primarily binds basic drugs, has been shown to increase in patients during stress such as trauma or surgery. The objective of this study was to determine the extent of meperidine binding to AAG and albumin as a function of both protein and meperidine concentrations. We performed a simple extraction procedure and a highly sensitive gas chromatograph analytical procedure. The results indicated that meperidine binding did not vary significantly with meperidine concentration at a given AAG concentration. However, meperidine binding increased significantly (p less than 0.01) as AAG concentration increased. Conversely, meperidine binding to albumin appeared to be independent of concentration of either meperidine or albumin. In conclusion, alpha 1-acid glycoprotein is a major plasma protein which binds meperidine in patients during stress. Further studies are suggested to elucidate the role of AAG on the pharmacologic effects of meperidine.

Cholinesterase Inhibitors↗

PubMedDate not supplied

Hazard of platelet transfusion in thrombotic thrombocytopenic purpura.

A patient with thrombotic thrombocytopenic purpura (TTP) showed for the first time catastrophic signs and symptoms of CNS involvement immediately after infusion of platelets. Postmortem examination revealed extensive deposits of platelet aggregates within the small blood vessels of the brain, whereas lesions elsewhere in the body consisted of platelets as well as fibrin and were associated with endothelial proliferation and microaneurysm formation. These findings are consistent with the view that the initial event in TTP may be platelet aggregation. The plasma of this patient contained platelet-aggregating activity. We conclude that platelet transfusions in patients with TTP may aggravate the disease process.

Acute Disease↗