ABSTRACT
Drugs that have small margins between therapeutic and toxic serum concentrations (narrow therapeutic indices) or drugs with no readily observable clinical end points are the most in need of dosage regimens tailored to the individual patient. Examples of drugs with narrow therapeutic indices are aminoglycoside antibiotics, warfarin, and digoxin. Additionally, drugs such as lithium and some anticonvulsants cannot be rapidly or safely monitored clinically because they could subject the patient to unnecessary toxicity or treatment failure.
