The discipline of pharmacokinetics (PK) applies mathematical models to describe and predict the time course of drug concentrations and drug amounts in body fluids.1–3 Pharmacodynamics (PD) applies similar models to understand the time course of drug actions on the body. Clinicians aremost concerned with pharmacodynamics—they want to know how drug dosage, route of administration, and frequency o...

toxin, have been commonly used for the treatment of congestive heart failure and other cardiac diseases. In addition to the narrow therapeutic range of the serum digitalis glycosides, their bioavailability is easily affected by kidney or liver failure and the dosing of other medicines. Therefore, it is important to accurately measure the digitalis glycosides in sera from digitalized patients. D...

FOR both practical and theoretical reasons there has long been a need for measuring blood levels of cardiac glycosides. From the practical standpoint the clinician is constantly confronted with patients in cardiac failure in whom it is difficult to determine whether there is too much or too little digitalis, and the wrong analysis may have serious or even fatal consequences. The problem is made...

FOR both practical and theoretical reasons there has long been a need for measuring blood levels of cardiac glycosides. From the practical standpoint the clinician is constantly confronted with patients in cardiac failure in whom it is difficult to determine whether there is too much or too little digitalis, and the wrong analysis may have serious or even fatal consequences. The problem is made...