The 1978 College of American Pathologists Therapeutic Drug Monitoring Interlaboratory Survey Program

In 1978 the College of American Pathologists introduced a Therapeutic Drug Monitoring Interlaborabory Survey Program. Each participant recieved six vials of lyophilized human serum on two occasions, approximately 13 weeks apart. The specimens contained various combinations of 12 drugs in subtherapeutic, therapeutic, and toxic concentrations. The drugs included in the specimens were phenytoin, phenobarbital, primidone, ethosuximide, carbamazepine, digoxin, procainamide, N-acetylprocainamide, quinidine, theophylline, lithium, and gentamicin. The weighed-in quantity of each drug was used as the target value for that drug. The specimens were analyzed by a variety of analytic methods. Statistics were calculated for all results regardless of the analytic method used and for each individual method. This report presents the data from the Program.