Pharmacology is the study of how drugs act on living systems, including their biological effects, therapeutic uses, and interactions. A drug is any substance that alters physiological systems. Pharmacokinetics describes what the body does to a drug through absorption, distribution, metabolism, and excretion, while pharmacodynamics describes what the drug does to the body through its mechanisms and effects. Drugs can be administered through various routes including oral, parenteral, topical, inhalational, and others. Proper drug nomenclature includes the chemical, generic, and trade names.

1. IntroductIon to
Pharmacology
Dr.Arul Amuthan
Lecturer in Pharmacology
Melaka Manipal Medical College
Manipal University 1

2.  pharmacology - drug study
What is Pharmacology ?
 Science that deals with the effects of drugs on living
system.
 Sources, biological effects, therapeutic uses,
adverse effects and interactions of drugs
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3. What is drug ?
 Substance that modify the physiological systems or
pathological state for the benefit of the recipient.
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4.  Pharmacokinetics:
What the body does to the drug
 Absorption, Distribution, Metabolism, Excretion
[ADME]
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5.  Pharmacodynamics:
What the drug does to the body
 Drug’s mechanism of action
 Pharmacological effects of drug
 Adverse effects of drugs
 Drug interaction
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Pharmacotherapeutics:
Application of pharmacological information together
with disease knowledge for prevention and cure
Selection of drug, dose, duration of treatment
Toxicology:
Harmful effects of drug
Detection, prevention, treatment of poisoning
Study of adverse effects

7. Clinical pharmacology:
 Scientific study of drugs in man
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 P.kinetic/dynamic investigation in healthy and patients
 Evaluation of efficacy and safety, adverse effects
 Comparative trails, Surveillance

8. SOURCES OF DRUGS
I. Natural sources
II. Semisynthetic sources
III. Synthetic sources
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9.  Plants:
Morphine, codeine, atropine, quinine, digoxin
 Animals: insulin, thyroxine
 Microorganisms: penicillin, streptomycin
 Minerals: iron, calcium, zinc
I. Natural sources:
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10. II Semisynthetic sources:
Ampicillin, Amoxicillin (semisynthetic penicillins)
Diacetyl morphine
III.Synthetic sources:
 paracetamol, erythromycin, pethidine
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Drug nomenclature:
Chemical name - Generic name - Trade name

12. 3.Trade name: (brand, proprietary name)
 Given by a pharmaceutical company
 Sole property of the pharmaceutical company
 A drug may have many proprietary names
 Same company – different name in different countries
 Prescription, over-the-counter drugs
 Ecospirin, Disprin (for aspirin)
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13. 2.Generic name:
Assigned by - United States Adopted Name (USAN) council
British Approved Name (BAN) council
Used uniformly in all countries
After the drugincludedin pharmacopeia - official name
 Aspirin, paracetamol
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14. 1. Chemical name:
Is the name of chemical compound present in a drug
 Acetyl salicylic acid, Acetaminophen
Not suitable for prescribing
Number is given before name is framed (Eg: INR00439)
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15. Sources of drug information
Pharmacopeia:
 Book containing names of officially approved drugs
with their physical and chemical characteristics.
 Eg: Indian Pharmacopoeia (IP)
 BP, USP
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16. Non-official references:
Physicians’ Drug Reference (PDR)
Dental Drug Reference (Mosby)
Monthly Index of Medical Specialists (MIMS)
Medical journals:
The Malaysian Journal of Medical Sciences
 Medical Journal of Malaysia, BMJ
US Food and Drug Administration (FDA): www.fda.gov16

17. 1. Enteral route: oral, sublingual, rectal routes
2. Parenteral routes: intradermal, subcutaneous,
intramuscular, intravenous, intra-arterial, intrathecal
3. Topical: skin and mucous membrane
4. Others: transdermal, inhalational
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Route of drug administration

18. Oral route: Advantages:
Safe, convenient for long use
Painless, self administered
Disadvantages:
 Slow onset of action (not used in emergency)
 Not suitable - in diarrhoea/vomiting/unconscious cases
- unpalatable/irritant drugs, unabsorbed drug
Aspirin, paracetamol, ibuprofen
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19. Sublingual: Advantages:
Quick onset of action, bypass first pass metabolism
 Self administered, terminated by spiting out
Disadvantages:
In children
Bad smell & lipid insoluble drugs
Nitroglycerin for angina
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20. Advantages:
Unpleasant drugs
In vomiting, unconscious cases
Disadvantages:
Inconvenient, embarrassing
Causes rectal inflammation
Prednisolone for ulcerative colitis
Ergotamine, diazepam for systemic effect
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Enema (fluid)
suppositories (tablets)
Rectal:

21. Parenteral routes & site:
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22. Intradermal:
Disadvantages:
Painful, no self administration
small amount of drug is administered
Eg: BCG vaccine, drug sensitivity tests
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23. Subcutaneous:
Advantages:
Self administration is possible
Depot can be inserted into sc
Disadvantages:
Slow absorption, not useful in emergency
Suitable only for non-irritant drugs
Eg: Insulin, adrenaline
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24. Intramuscular:
Advantages:
Rapid absorption
Depot injections
10 ml can be given at a time
Useful in vomiting, diarrhea, unconscious patients
Bypass first pass metabolism
Disadvantages:
Sterilization required
Painful, no self administration
Injury to nerve, cause abscess
Eg: gentamicin, streptomycin, kanamycin 24

25. Intravenous: Advantages:
Directly reaches blood
Bypass first pass metabolism, 100% bioavailability
Emergency – fast onset of action
Large volume infused – iv fluids
High irritant drugs is given
Useful in vomiting, diarrhea, unconscious patients
Eg: furosemide, diazepam
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26. Intravenous: Disadvantages:
Once administered, can’t be stopped
Painful, no self medication
Strict aseptic precautions
Extravasation causes tissue necrosis
Causes thrombophlebitis
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27. Topical: (skin and mucous membrane)
Advantages:
More convenient, encouraging to patient
Efficiently delivered to local lesion areas
Disadvantages:
Local irritation, dermatitis
silver sulfadiazine ointment, diclofenac gel
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28. Transdermal/Transcutaneous:
Adhesive patch
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29. Advantages:
Self administered, better patient compliance
Prolonged duration of action
Less systemic side effect
Disadvantages:
Expensive
Local irritation causes dermatitis, itching
Patch may fall off unnoticed
scopolamine, nitroglycerine, oestrogen
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30. Inhalational:
Volatile liquids and gases are given for systemic effects
Advantages:
Absorption through alveoli, rapid onset of action
Less dose is enough, so less systemic toxicity
Amount of drug can be regulated
Disadvantages:
Irritation causes bronchospasm and high secretion
General anaesthetics – nitrous oxide, ether, halothane
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31. Drug into subarachnoid space - Intrathecal
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 Intrathecal – lignocaine, amphotericin
 Intra articular – hydrocortisone

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