Serum Drug Concentrations as Therapeutic Guides

Abstract

DRUG dosages needed for optimal therapeutic effects differ widely among patients. The "usual dose" of most potent drugs accomplishes little in some persons, causes serious toxicity in others, and is fully satisfactory in few. The inability of standard dosage schedules to exert a sufficiently intense pharmacologic effect in many patients is often misinterpreted as therapeutic ineffectiveness of drugs. Conversely, drug toxicity is often caused by the failure to reduce the usual dosage appropriately in other patients. The importance of the latter problem is pointed up by the frequency and severity of adverse reactions to drug therapy. More than half these . . .