Clinical Chemistry and Hematology Laboratories

• Therapeutic Substance Monitoring (TSM) Proficiency Testing Program

Pharmacologists demonstrated in the 1970s improved clinical outcomes derived from monitoring blood levels of drugs that were administered to control epileptic seizures. Although the patients were prescribed dosages presumed adequate to achieve therapeutic levels of drug(s), the investigators found large interindividual differences in peak and trough blood levels. Interindividual differences in the absorption, distribution, metabolism, and elimination of drug(s) produced blood levels that were therapeutic in some, but subtherapeutic or toxic in others. The determination of blood levels guided dosage adjustment until optimal drug levels were achieved.

Today, therapeutic drug monitoring (TDM) is standard medical practice in the management of many medical conditions where the dose-concentration relationship is not reliably predicted and where untoward effects are manifest if blood level of drug is not maintained within a therapeutic window. About 425 clinical laboratories provide TDM services to physicians in New York State. The Toxicology Laboratory in the Division of Molecular Medicine uses its resources to ensure that the quality of service provided by clinical laboratories is consistent with physician requirements for optimal patient care.