What is An Adverse Drug Reaction?

Response to a drug which is noxious and unintended and occurs at doses normally used for prophylaxis, diagnosis and therapy of disease.

The untoward harmful effects are classified as adverse drug reactions. But Side effects however may be beneficial or harmful.

Adverse drug reactions and side effects fall under a broad concept named “Adverse event”

Adverse event refers to any harm or injury a patient sustains on taking a drug
There are 6 main types of adverse drug reactions based on timing:
Type A- augmented
Type B – bizarre
Type C- chronic
Type D- delayed
Type E – end of use
Type F- failure of therapy

Grading Severity of Adverse Reactions.
1. mild
2. moderate
3. severe
4. life-threatening

A reaction may be Severe in intensity but not Serious

Serious means the adverse event:
1. Results in death
2. Is life-threatening
3. Requires inpatient hospitalization
4. Results in significant disability
5. Is a congenital anomaly

Factors Influencing Incidence of Adverse Drug Reactions
1. Age
2. Gender
3. Genetic factors
4. Renal function
5. Polypharmacy

The Naranjo Algorithm is used for classifying causality of adverse drug reactions.

9 Definite ADR
5-8 Probable ADR
1-4 Possible ADR
0 Doubtful ADR

Management of ADRs
1. Discontinue with suspected drug
2. Dose reduced
3. Replacement of suspected drug
4. Desensitization

*FACT*: NIFEDIPINE (a cardiovascular drug) IS THE MOST REPORTED MEDICATION ACCORDING TO FDA REPORT 2014

  • *Emmanuel Ofori*
    *MJA*