ADR Types and Monitoring Systems
An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs. The meaning of this term differs from the term "side effect" because side effects can be beneficial as well as detrimental. The study of ADRs is the concern of the field known as pharmacovigilance. An adverse drug event (ADE) refers to any unexpected and inappropriate occurrence at the time a drug is used, whether or not associated with the administration of the drug. An ADR is a special type of ADE in which a causative relationship can be shown. ADRs are only one type of medication-related harm, as harm can also be caused by omitting to take indicated medications.
WHO Definition of Adverse drug reaction:-
Any noxious change which is suspected to be due to drug occurs at doses normally used in men, requires treatment or decreases in dose or indicates caution in further use of the some drug .
Classification of Adverse drug reaction
On the basis of severity
Minor ADRs
Moderate ADRs
Severe ADRs
Lethal ADRs
On the basis of onset of event
Acute ADRs
Subacute ADRs
Latent ADRs
On the basis of types of reaction (Wills and brown)
Type A (Accumulated)
Type B (Bizarre)
Type C ( Chronic)
Type D ( Delayed)
Type E ( End of treatment)
Type F ( Failure of therapy)
Other Adverse drug reaction
Side effect
Toxicity
Drug dependent
Drug induced diseases
Type of reaction
(Wills and brown)
Type A reactions:- These are most common type
of ADRs and occur as a result of drug's known pharmacological actions.
They are usually dose-dependent and may include symptoms such as nausea,
headache, or dizziness.
Type B reactions:- These
are unpredictable and other related to the known pharmacological actions of the
drug. They may caused by individual differences in genetics or metabolism and can include allergic reactions, such as hives or
anaphylaxis.
Type C reactions:- These
are Chronic reaction that occur after
prolonged use of medication. They may
include effects such as liver damage or bone marrow suppression.
Type D reaction:- These are delayed reaction that occur after prolonged use of medication.
They may include effects such as tardive dyskinesia or drug induced
Parkinsonism.
Type E reaction:- These
are end of treatment reactions that occur when the medication is discontinued.
They may include rebound effects,
such as rebound hypertension or rebound
insomnia.
Type F reactions:- These are unexpected Failure of therapy, where the patient does not experience the therapeutic effect of the drug. This may be due to drug interactions, patient non-compliance or some other factors.
Adverse Drug Reaction Monitoring
Spontaneous reporting:- Healthcare professionals, patients, caregivers, can report ADRs to regulatory such as the FDA or the European Medicines Agency ( EMA) . The reports are then analyzed to identify patterns and potential safety issues.
Electronic health records ( EHRs): can be used to track medication use and any adverse events that may occur. This allows healthcare professionals to identify potential ADRs in real time and take appropriate action.
Clinical trials: ADRs are monitor in clinical trials to assess the safety of medications before they approved for use in the general population.
Post marketing surveillance :- Once a medication is approved for use , post -marketing surveillance is conducted to monitor ADRs Ina larger population. This can identify any potential safety issues that were not detected in clinical trails.
Overall, ADR monitoring is an important part of ensuring
medication safety and protecting patient
health.
