Personalization of drug dose thematic issue: introduction article

ABSTRACT

Introduction

The need to individualize a drug dosage and adjust it to a patient’s physiological and/or pathophysiological status is rarely satisfied in routine clinical practice, primarily because of complexity of the adjustment task.

Areas covered

The aim of this article is to shed light to basic principles of drug dosage individualization in the most frequent clinical states that affect pharmacokinetics of drugs. The principles are derived from published clinical studies conducted on diverse patient populations, using non-compartmental pharmacokinetic model.

Expert opinion

Simple, but sufficiently exact, way to calculate appropriate drug dose for a patient is the one based on target average steady-state concentration and non-compartmental pharmacokinetic model. If target steady-state drug concentration and dosage interval are considered fixed, maintenance dose could be adjusted on the basis of expected changes of total drug clearance and bioavailability, while loading dose should be related to changes of volume of distribution and bioavailability. Relative increase or decrease of these pharmacokinetic parameters in regard to normal values in healthy persons is translated to relative (percentual) increase or decrease of maintenance and loading doses recommended in the drug monograph.

KEYWORDS:

• Drug dosage individualization
• pharmacokinetics
• pathophysiology

Article highlights

• Knowing functional state of a patient’s vital organs, and how it affects the key pharmacokinetic parameters of a drug being prescribed is a prerequisite for successful dose individualization.

• Simple dose individualization method based on target average steady-state plasma concentration of a drug and non-compartmental pharmacokinetic model could be used with pencil and paper, at the point of care.

• Influence of patient’s conditon on a drug pharmacokinetics depends on its solubility and permeability, i.e. on its belonging to certain class of Biopharmaceutics Classification System.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was funded by grant No 175007 by Ministry of Education, Science and Technological Development, Serbia.