ADVERSE DRUG REACTIONS: AN OVERVIEW OF THE OLD AND CONTINUOUS CHALLENGE TO DRUG THERAPY AND DEVELOPMENT

Abdelbaset A Elzagallaai

doi:10.5542/ljpcp.v3i0.v1i0.571902

Abstract

Adverse drug reactions (ADRs) represent a major health problem worldwide and constitute a big challengeto drug therapy and the drug development process. ADRs are responsible for 3% of total hospital admissions and occur in 10 to 20% of hospitalized patients. It has been estimated that ADRs account for at least 100,000 deaths annually in the United States alone ranking them as the fifth leading cause of death. According to the World Health Organization definition an ADR is a noxious and unintended response to a drug that occurs at a dose normally used in man for prophylaxis, diagnosis or therapy. This commonly used definition, however, excludes other drug therapy consequences such as drug abuse, accidental and inadvertent drug overdose and therapeutic failure. ADRs are classified into two main groups: Type A, which are predictable from the drugs’ normal pharmacological actions and are dose dependent and Type B, which are unpredictable, unrelated to the drugs’ pharmacology and do not have clear dose dependency. This is an overview of the currently used definitions and classifications of ADRs in clinical pharmacology and toxicology. Specific relevant examples are cited and some important points are discussed in the light of current knowledge. A special emphasis is made on the importance of ADRs in clinical drug therapy and drug development, which are the areas where ADRs play the most significant role.

Highlights

Iatrogenic diseases have always been a concern to medical practitioners
The history of medicine and drug therapy is full of disasters of adverse drug events in addition to the everyday patient suffering and extra healthcare costs caused by these events
‘It is a duty of the muhtasib that he exact from practitioners of medicine the oath of Hippocrates, that they will not administer a harmful drug, that they will not prescribe a poison for a patient, that they will not describe poisons to the people, that they will not inform a woman of a drug which abort the embryo nor a man to avoid conception, that they will turn their eyes from the women’s quarters when they enter them to visit a patient, that they will not reveal secrets and not tear away the veil, and that they will not be inquisitive in what should remain unknown’[7]

Summary

INTRODUCTION

Iatrogenic diseases (diseases caused by Physician intervention and self medication) have always been a concern to medical practitioners. According to the WHO definition, which has been in use for more than forty years, an ADR is a noxious and unintended response to a drug that occurs at a dose normally used in man for prophylaxis, diagnosis or therapy [9]. This definition is too strict and does not include all adverse drug effects [10]. The WHO definition excludes events such as medication errors, drug abuse, accidental and intentional overdose and therapeutic failure Another term, adverse drug events (ADE), was introduced to cover all these effects. Type A reactions, which are usually predictable, dose-dependent and related to the pharmacological action of the drug, and type-B reactions, which are unpredictable, have delayed onset, are typically unrelated to the drug pharmacology and do not have clear dose-dependency, Table 1and Figure 1. [15]

Affect Drug PD

Neutrophils mediated inflammatory response

Findings

CONCLUSION