Adverse Drug Reactions (ADR)

ADVERSE DRUG REACTIONs (ADRs)

It has been recognized since the earliest times and now universally accepted that no drug is free from side effects and that drug therapy itself can be a significant cause of morbidity and mortality.

Definition of adverse drug reaction (ADR)  
An ADR is basically any undesirable effect of a drug beyond its anticipated therapeutic effects occurring during clinical use.

Several definitions of ADR exist in literature, including those of World Health Organization (WHO), Karch and Lasagna, American Society of Health- system Pharmacists (ASHP), and United States Food and Drug Administration (USFDA).

WHO defines ADR as a response to a drug which is noxious and unintended, and which occurs at doses normally used in man for the prophylaxis, diagnosis, or therapy of disease, or for the modification of physiological function.

 

Karch and Lasagna have defined an ADR as any response to a drug that is noxious and unintended and that occurs at doses used in man for prophylaxis, diagnosis, or therapy, excluding failure to accomplish the intended purpose.

 

American Society of Hospital Pharmacists (ASHP) has defined an ADR as any unexpected, unintended, undesired, or excessive response to a drug that

I. Requires discontinuing the drug (therapeutic or diagnostic),

II. Requires changing the drug therapy,

III. Requires modifying the dose (except for minor dosage adjustments),

IV. Necessitates admission to a hospital,

V. Prolongs stay in a health care facility,

VI. Necessitates supportive treatment,

VII. Significantly complicates diagnosis,

VIII. Negatively affects prognosis, or

IX. Results in temporary or permanent harm, disability or death.

United States Food and Drug Administration (USFDA) has defined an ADR as  any events relating to drugs or devices in which the patient outcome is death, life-threatening (real risk of dying), hospitalization (initial or prolonged), disability (significant, persistent, or permanent), congenital anomality, or required intervention to prevent permanent impairment or damage.