Introduction to Therapeutic Drug Monitoring

Abstract

SummaryTherapeutic drug monitoring is defined as measuring serum concentrations of a drug in a single or multiple time points in a biological matrix after a dosage. The purpose of therapeutic drug monitoring is to individualize the dosage to achieve maximum efficacy of a drug and at the same time minimize adverse drug reactions. Therapeutic drug monitoring has clinical importance for drugs with a narrow therapeutic window, such as various anticonvulsants, cardioactive drugs, theophylline, immunosuppressants, tricyclic antidepressants, antiretroviral drugs, certain antibiotics, and neoplastic drugs. Altered pharmacokinetic parameters are observed for many drugs in disease states including hepatic and renal impairment, cardiovascular disease, thyroid dysfunction, and cystic fibrosis. Altered drug disposition also occurs in pregnant women. Therapeutic drug monitoring helps to identify such altered drug disposition, and dosage adjustment can be made for proper management of the patient to avoid adverse reactions. Therefore, therapeutic drug monitoring is cost effective in heath care.