Drugs and children: methods for therapeutic monitoring.

In this era of polypharmacy, the incidence of adverse reactions due to drug therapy has increased alarmingly since the precise effects on the metabolism of a drug given in combination with other drugs can never be predicted with certainty. Inadequate therapy due to insufficient medication or to factors which diminish absorption or enhance metabolism may be equally undesirable. The consequences to patients in terms of increased morbidity and financial cost of prolonged hospitalization may be considerable. For pediatric patients, particularly in the newborn period, these hazards may be much more dangerous. There is a need for more investigation into the validity of procedures in current use for the determination of drug levels in biologic fluids and into the interpretation of the values they produce. In addition clinical chemists and clinical pharmacologists are faced with the challenge of defining those drugs for which blood level information would be advantageous and developing rapid, sensitive, and accurate assays which can be performed by the routine clinical laboratory. The day may be not too far away when a major proportion of the workload of the clinical laboratory consists of assays primarily designed as an aid to therapy rather than diagnosis.