This document provides an overview of pharmacology, including the key topics of pharmacokinetics, pharmacodynamics, drug properties, and drug administration. It defines pharmacology and its two main divisions - pharmacokinetics concerning what the body does to drugs, and pharmacodynamics regarding what drugs do to the body. The processes of absorption, distribution, metabolism and excretion of drugs are described. Factors influencing drug action and effects on receptors are also summarized.

1. By:-Upendra Agrawal
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2. 1. Introduction
2. Pharmacokinetic
3. Pharmacodynamic
4. Drug
5. Various physiochemical properties the of drugs
6. Drug receptor interaction
7. Routes of administration
8. Conclusion
9. References
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3.  Pharmacology: It is the science of drugs as it deals
with the interaction of exogenously administered
chemical molecule (Drug) with living system.
 Father of pharmacology: Oswald Schmiedeberg.
Two main division of pharmacology are:
1. Pharmacokinetic : what the body does to drug
2. Pharmacodynamic: what the drug does to body
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4. It is the quantitative study of drug movement in,
through and out of the body.
Schematically process of pharmacokinetic:
Transportation Absorption Distribution-
storage
receptor metabolism free drug
binding :
(Effect) excretion. 4

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6. Drugs are transported across the membrane by:
1.Passive diffusion and filtration.
2. specialized transport or carrier mediated:
a. Facilitated diffusion.
b. Active transport .
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7. Absorption is movement of the drug from its site of
administration in to the circulation.
factor affecting absorption:
a. aqueous solubility
b. concentration
c. area of absorbing surface
d. vuscularity of the absorbing surface
e. Ph influence
f. Route of administration
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8. It is the fraction of the drug that reaches to systemic
circulation from a given dose in unchanged from in
an unchanged form.
Intravenous route gives 100% bioavailability as it
directly enters the circulation.
The term bioavailability is generally used for drugs
given through oral route.
Bioequivalent: Two formulation of the same drug
having equal bioavailability.
Bioinequivalent: if formulation differ in there
bioavailability.
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9. Once a drug has gained access to the blood stream, it gets distributed to
other tissue that initially had no drug , concentration gradient being
in the direction of plasma to tissue.
Factor affecting drug distribution:
a. lipid solubility (various barrier)
b. ionization at physiological Ph
c. extent of binding to plasma and tissue protein
d. presence of tissue specific transporter
e. difference in the regional blood flow
f. First pass metabolism.
Movement of the drug proceed until an equilibrium is
established between unbound drug in plasma and tissue fluids.
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10. It means chemical alteration of the drug in the body.
Primary sites of drug metabolism is liver , others are –
kidney, intestine lungs and plasma.
Biotransformation of drug may lead may lead to the
following:
a. Inactivation
b. Active metabolite from an active drug
c. activation of inactive drug (prodrug).
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11. Excretion is the removal of the drug and its metabolite
from the body.
Drugs and their metabolites are excreted in:
1. Urine
2. faeces
3. exhaled air
4. saliva and sweat
5. milk
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12. Pharmacodynamic is the study of drug effects. It attempts
to elucidate the complete action-effect sequence and dose-
effect relationship.
Principles of drug action:
drugs do not impart new function to any system , organ or
cell they only alter the pace of ongoing activity.
Types of drug action:
1. Stimulation
2. Depression
3. Irritation
4. Replacement
5. Cytotoxic action
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13. Majority of the drugs produce their effect by interacting
with a discrete target biomolecule.
There are four major target of drug:
1. Enzymes
2. ion-channel
3. Transporters
4. receptors.
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14. It is a single chemical entity present in a medicine that
is used for diagnosis, prevention, treatment/cure of a
disease.
According to the WHO : Drug is any substance or
product that is used or is intended to be used to
modify or explore physiological system or pathological
states for the benefits of the recipient.
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15. 1. Lipid water solubility
2. Molecular size
3. Particle size
4. Degree of ionization
5. Physical forms
6. Chemical nature
7. Dosage forms
8. Formulation
9. Concentration
10. Shape
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16. Receptor are (specific) protein and have specificity and
selectivity . No drug is truly specific but many have
a relatively selective action on one type of
receptor.
Drug+ receptor Drug –receptor complex
Response
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17. Affinity: the ability of the drug to get bound to the
receptor is known as affinity.
Intrinsic activity: The ability of the drug to produce a
pharmacological action after combining with the
receptor.
Agonist: A drug that is capable of producing
pharmacological action after binding to the receptor.
Antagonist: drugs that bind to receptor but are not
capable of producing pharmacological action. These
produce receptor blockade.
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20. Pharmacology is both a basic an applied science. It
forms the backbone of rational therapeutics.
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21. KD TRIPATHI , Edition 6th year 2010 , published by
JYPEE BROTHER MEDICAL PUBLISHER.
TARA V SHANBHAG, edition 1st year 2011 ELSEVIER.
WWW.themednote.com
Wiki.ubc.ca/biological_membrenes
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