Clinical Pharmacist and Clinical Pharmacologist Opinion of Narrow
Therapeutic Index (NTI) Drugs
Abstract
Purpose: If the drugs are routinely required for therapeutic drug
monitoring (TDM), they may be considered NTI drugs. By basing some
criteria that affect the degree of separation of the concentrations that
elicit the therapeutic and the adverse effects, an attempted to avoid
the vagaries inherent in preparing a list of individual drugs
themselves. Methods: I reviewed over 200 commonly prescribed drugs in
the retail and hospital pharmacies in the US. As the Food and Drugs
Administration (FDA) clinical pharmacologist and as practicing clinical
pharmacist in hospitals for 25 years, there are no drugs that of concern
than the Narrow Therapeutic Index (NTI) drugs. Results: NTI drugs are
very dangerous in that any small change in the dose or concentration or
interaction with any drugs, may end up with major consequences. That is
why in hospitals, NTI drugs are routinely monitor such as vancomycin and
gentamicin. Similarly, at the FDA, it is essential that labels specify
the drug levels for certain conditions or diseases that are being
monitoring. Conclusions: The plasma levels sometimes are required for
in-patient and out-patient for drugs such as valproic acid, digoxin, and
theophylline. It is essential that NTI must be monitored in-patient and
out-patient.