1. An adverse drug reaction (ADR) is an unwanted effect that occurs when taking a medication at normal doses. ADRs can be caused directly by the pharmacological properties of the drug. 2. Factors that contribute to more ADRs globally include an increasing number of drugs on the market, an aging population, and more frequent polypharmacy or use of multiple medications. 3. Monitoring and reporting of ADRs aims to help regulators and health programs identify risks to reduce ADRs, find safety issues with medications, and recognize risk factors for developing ADRs based on patient characteristics or drug interactions.

1. ADVERSE DRUG REACTIONS
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2.  Adverse drug reaction (ADR)
According to the WHO, an ADR is defined as “ a response to a drug which is noxious and
undesired and which occurs at normal doses when used in man for prophylaxis, diagnosis or
therapy of disease or for the modification of physiologic function.” Thus, an ADR is a type of
ADE whose cause can be directly related to a drug and its physiologic properties.
*ADR can be defined as an unwanted, undesireable effect of a medicine that occurs during
usual clinical application.
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3. Factors responsible for the prevalence of ADRs worldwide are:
1. Increase in the number of drugs in the market.
2. An aging population
3. An upward trend in polypharmacy
ADR: occur even after appropriate prescription and correct dosing.
ADE: Associated with inappropriate use of the drug that usually
occurs during drug therapy. Not related to pharmacology of the drug
itself. May occur due to medication errors.
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4. Objectives of ADRs Monitoring
 A. To help the drug regulatory authority, public health programmes, scientist and consumers for taking
appropriate action to reduce the risks of ADRs.
 It is also necessary to find out the nature and frequency of ADRs with periodical check of the benefit-risk ratio of
medicinal products.
 B. To identify the risk factors that may affect, induce or influence the development, severity and incidence of
adverse reactions in the population.
 a. Patient factors such as genetics, racial differences,diets,diseases,pattern of drug use and food habits.
 b. Drug interactions, drug distribution, storage and use including indications,dose, availability and other
underlying conditions.
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6. Classification of ADR
Drug Induced ADRs Are Classified On The Basis Of :
1. Pharmacological Mechanism
2. Preventability Of ADR
Pharmacological Mechanism
-Simple Method Of Classification
-Proposed By Rawlins In 1981
Two Types Of ADR: Type AAnd Type B.
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7. PREDICTABLE ADRS CAN BE CLASSIFIED ON THE BASIS OF:
1.OVER DOSES
2.ADVERSE EFFECTS
3. DRUG DRUG INTERACTION
4. DRUG DISEASE INTERACTION
UNPREDICTABLE ADRS MAY HAPPEN DUE TO:
1.INTOLERANCE
2.ALLERGY
3.PSEUDO ALLERGY
4.IDIOSYNCRASY
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8. FEATURES TYPE A TYPE B
PHARMACOLOGY AUGMENTED STRANGE
PREDICTABLE YES NO
DOSE-DEPENDENT YES NO
MORBIDITY HIGH LOW
MORTALITY LOW HIGH
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23.  Drug dependence
1. Psychological dependence
2. Physical dependence
3. Drug Abuse
4. Drug Addiction
5. Drug Habituation
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24. Teratogenicity
Capacity of a drug cause foetal abnormalities when administered to the pregnant mother.
Example-
• Thalidomide- Phocomelia, multiple defects
• Anticancer drugs- Cleft palate, multiple defects
• ACE inhibitors- Hypoplasia of organs (lungs and kidney)
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25. Mutagenicity-
Capacity of a drug to cause genetic defects and cancer respectively.
Carcinogenicity-
Chemical carcinogenesis generally takes several (10-14)years to develop.
Example: anticancer drugs, radioisotopes, estrogens, tobacco,etc
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26. Drug induced disease
 Also known as Iatrogenic (Physician induced disease).
 Example: Salicylates, corticosteroids- Peptic ulcer
 Phenothiazines- Parkinsonism
 Isoniazid- Hepatitis
 Hydralazine-DLE
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27. Predisposing factors of ADRs and the mechanisms of
drug interaction
 Age
 Pathophysiological conditions
 Amount of drug administered
 Sex
 Previous history of allergy
 Racial or genetic factors
 Multiple drug therapy (Polypharmacy)
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28.  Mechanisms of drug interactions due to polypharmacy:
i. Direct physical or chemical interactions
ii. Altered GI absorption
iii. Competition for protein binding
iv. Increased or decreased metabolism of a drug by induction
v. Activation or inhibition of drug metabolizing enzymes
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29. Detection and Reporting
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30.  A health care professional should bear in mind when reporting an ADR that ADR reports are
only suspected associations that a drug has caused a particular adverse event.
 Reporting an ADR does not imply a causal association between the drug and ADR.
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31. What to report
 When undesireable adverse events are suspected to be associated with use of drug, biologicals (including blood
products), herbal drugs, cosmetics or medical devices, it should be reported.
 The minimal information to be provided for proper assessment of the ADR case report is given below:
 1.Patient information
 2. Description of ADR
 3. Information related to the suspected drugs.
 4. Information about how the adverse reactions had been managed.
 5. Information about the reporter
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32.  Patients information
1. Patient identity
2. Birth dates or age
3. Gender
4. Weight
 Adverse reactions
1. Brief description of ADR
2. Time/date of onset of the adverse reactions
3. Other related information
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33.  Suspected drug(s)
1. Name of the suspected drugs
2. Dosage,frequency and route of administration
3. Therapy date
4. Batch number and Expiry date
5. Reasons for use
6. Particulars of drugs or other treatment administered or continued simultaneously
7. Relevant information on medical devices
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34. Thank you
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