INCLUDES NOTES BASIS OF PHARMACOLOGY'S INTRODUCTION

1. Introduction to pharmacology
Presentation by: Sanjog Bam

2. • Pharmacology: science of drugs{Greek:
pharmacon- drug; logos – discourse in}
– In a broad sense, it deals with interaction of
exogenously administered chemical molecules
(drugs) with living system
– It encompasses all aspects of knowledge about
drugs, but most importantly those that are
relevant to effective and safe use for medicinal
purpose.
– The first pharmacology department was set up by Rudolf
Buchheim in 1847 in Germany as the moto to understand
how therapeutics drugs and poison produces their effects.
The is the one who ushered the pharmacology as the
experimental science
– In the later part of the 19th century, Oswald Schmiedeberg,
regarded as the ‘father of pharmacology’, together with his
other colleagues propounded some of the fundamental
concepts of pharmacology.

3. The main two divisions of
pharmacology are
1. Pharmacodynamics:{ Greek: dynamis –power}
• What the drugs does to the body?
eg: Adrenaline adrenoreceptor(α,β)
Cell membrane bounded Adenylyl cyclase stimulated
by G protein sub unit
cAMP increases intracellularly
Cardiac stimulation
Hepatic glycogenolysis
Hyperglycemia etc

4. 2. Pharmacokinetics: { Greek: kinesis-movement}
What body does to the drug?
For eg: paracetamol(NSAIDS) is well absorbed orally with peak blood level in 20-30 minutes.
25% bounded with plasma proteins, widely and uniformly distributed in the body. Volume of
distribution= approx. 1 L/kg
Completely metabolized in liver through conjugation process and excreted through urine.
T1/2 = 2-3 hrs clearance value: 5ml/kg/min
Drug :{ french: Drogue- a dry herb}
the single active chemical entity of medicine used for diagnosis, prevention,
treatment/ cure of a diseases. But this definition of drug doesn’t include
contraceptive and health improving drugs
WHO(1966): Any substances or products that is used or is intended to be used
to modify or explore physiological systems or pathological states for the benefit
of the recipients.
Pharmacotherapeutics: It is the application of pharmacological information
together with knowledge of the diseases for its prevention, mitigation or
cure.
Selection of most appropriate drugs, dosages and duration of treatment taking into account the
specific features of patients are a part of pharmacotherapeutics.

5. • Medicine: drug taken to cure and/or ameliorate any
symptoms of an illness or medical conditions, or may be used
as preventive medicine that has future benefits but doesn't
treat any existing or pre-existing diseases or symptoms.
• Pro-drug:
 these are drugs which are administered as inactive form
and later converts into one or two active metabolite form
within the body parts(liver, stomach, brain, kidney etc)thus
showing their therapeutical effects
 Offers advantages over the active form in being more
stable, having better bioavailability or other desirable
pharmacokinetics properties or less side effects and
toxicity.
 Eg: L-dopa, acyclovir, prednisone etc

6. Pro-drugs are of two types based on
the sites of conversion:
• Type I: converted to active form intracellularly.
– Eg:antiviral nucleosides analogs, lipid lowering drugs,
antibody –directed/ gene-directed enyme for
chemotherapy, morphine to codeine.
• Type II: converted to active form extracelluarly.
 most converted in digestive juices or systemic
circulation eg etoposide phosphate, valganciclovir,
fosamprenavir.
 Some converted into CSF: L-dopa to dopamine

7. • Crude drug: It is any naturally, unrefined substances
derived from organic or inorganic sources such as
plants, animals, bacteria, organs or whole organism
intended for use in the diagnosis, cure, mitigation,
treatment, and or prevention of diseases in man or
other animals.
• Noortropics :
 commonly referred as “ smart drugs”, that are claimed to
improve human cognitive abilities.
 Used to improve memory, concentration, thought, mood,
learning etc
 Some now beginning to be used to treat certain diseases
such as attention-deficit hyperactivity disorder, Parkinson's
disorder, and Alzheimer's disease.
 Commonly used to regain brain function lost during aging.

8. • Chemotherapy: it is the treatment of systemic
infection/ malignancy with specific drugs that
have selected toxicity for the infecting
organism/malignant cell with no/minimal effects
on the host cells.
• Clinical pharmacology: it is the scientific study of
drugs in the person.
It includes pharmacodynamics and pharmacokinetics
investigation in healthy volunteers and in patients;
evaluation of efficacy and safety of drugs and comparative
trials with other forms of treatment ; surveillance of
patterns of drugs use, adverse effects etc
Its aim is to generate data for optimum use of drugs and the
practice of evidence based medicine.

9. • Pharmacy:
 It is the art and science of compounding and
dispensing drugs or preparing suitable dosage forms
for administration of drugs to human or animals.
 It includes collection, identification, purification,
isolation, synthesis, standardization and quality
control of medicinal substance.
 The large scale manufacture of drugs is called
pharmaceutics
• Toxicology : it is the study of poisonous effects of
drugs and chemical ( household, environmental
pollutant, industrial, agricultural, homicidal) with
emphasis on detection, prevention and treatment
of poisoning.

10. • Poison : The substances which endangers life by
severely affecting one or more vital functions
• Pharmacognsy: It is the study of medicine
derived from natural sources.
• Therapeutical window:
– It is the amount of a medication between the amount
that gives an effects(effective dose) and the amount
that gives more adverse effects than desired effects
– Therefore medication with small therapeutical
window must be administered with care and control.
– by frequently measuring blood concentration of the
drugs , since it easily loses effects or gives adverse
effects

11. Classification of drugs
• Therapeutic use:
Antimicrobial agents
Antihypertensive agent
Anaesthetic agents
Anti-diabetic agents
Analgesics etc
• Mode of site of action:
Receptor blocker: adrenoreceptor blocker: propanolol
Enzyme inhibitors: ACE inhibitors: Captopril, enalapril
Cellular site: loop diuretics: furosemides
• Thiazides, spirolactone,catecholamines, uptake
inhibitor(impiramine)
Molecular structure:
• Glycosides : digoxin
• Alkaloid : morphine, atropine
• Steroid : estrogen, progesterone

12. Drug nomenclature
• All drugs have names in all the following classes:
A. Chemical name: it involves substances with chemical
structure nomenclature.
 Eg: 1-(isopropylamino)-3(1-naphthyloxy)propan-2-ol
B. Non-proprietary(official, approved, generic)
name: it is used in pharmacopoeias and chosen by official
bodies, recommended international Non proprietary Names,
are chosen by WHO, but national and regional differences
persist.
eg: propranolol
C. Proprietary (brand) name: it is the name assigned by the
pharmaceutical company. It is a trade mark applied to particular
formulation of a particular substance by a particular manufacturer.
Eg: Inderal

13. Sources of drugs
The various source of drugs are
• Mineral
a. liquid paraffin b. Magnesium sulfate
c. magnesium trisilicate d. kaolin
• Animal
a. Insulin b. thyroid extract
c. Heparin d. Gonadotropins
• Plant
a. Morphine b. digoxin
c. Atropine d. reserpine
• Synthetic
a. Aspirin b. sulfonamide c. corticosteriod
• Micro-organism
a. antiboitics(Penicillin, Bacitracin)

14. • Drug produced by the genetic engineering:
(DNA recombinant technology)
e g: Human insulin, human growth hormone.

15. Routes of drug administration
• The choice of appropriate in a given situation
depends both on the drug as well as the patients
conditions.
• Entrance site of drug is far from target tissues or
organs, thus requires circulation to get into
intended sites.
• Six rights of drug administration:
Right patient
Right drug
Right dose
Right time
Right documentation
Right route

16. • Mostly common sense considerations, feasibility and
convenience dictate the route to be used.
• Factors governing choice of route:
Physical and chemical properties of the drug:
 Solid, liquid, gas
 Solubility, stability, pH, irritancy
Site of desired action
 Localized or generalized
Rate and extent of absorption of drug from different
routes.
Effect of digestive juices and first pass metabolism on the
drug.
Rapidity with which the response is desired
 Routine treatment or emergency
Accuracy of dosage required
 i.v and inhalational can provide fine tuning
Condition of the patient (unconscious, vomiting)

17. Routes can be classified
a. Local routes b. Systemic routes
 Local routes:
a. Applicable for localized lesions at accessible sites and for
drugs whose systemic absorption from the site is minimal
or absent.
b. High concentration are attained at the desired site
without exposing the rest of the body.
c. Very less systemic side effects and toxicities
The following routes are considered as local routes:
 Topical:
• External application of the drug to the surface for localized
action.
• More convenient as well as encouraging to the patients.

18. Drug can be efficiently delivered to the localized lesions
on
Site Drug form
Skin Ointment, cream , lotion, paste, powder
Mucous membrane
Mouth and pharynx Paints, lozenges, mouth washes, gargles
Eyes, ear and nose Drops, ointments, irrigation, nasal spray
Gastrointestinal tract (non-absorbable
drugs)- from mouth and rectally
Sucralfate, vancomycin, neomycin
Respiratory tract Inhalation, aerosols( salbutamol,
cromolyn sodium)
Uretha Jellys/ irrigating solutions(povidone
iodine, lidocaine)
Vagina Pessaries , vaginal tablets
Anal canal Ointment, suppositories

19. Deeper tissues:
 Certain deep areas can be approached by using a
syringe and needle , but systemic absorption is slow.
 Eg: intra-articular injection(hydrocortisone acetate),
infiltration around a nerve or intra-thecal
injection(lidocaine), retrobulbar injection
(hydrocortisone acetate)
Arterial supply:
 close intra-arterial injection is used for contrast media
in angiography.
 Anticancer drugs can be infused in femoral or brachial
artery to localize the effect for limb malignancies.

20. • Enemata: administration of a medicament in a liquid
form into rectum is called enema.
• Types of enema :
Evacuant enema: Soap water enema
Retention enema: prednisolone enema
Systemic routes
1. Oral or Enteral routes:
This is the commonest and oldest mode of drug administration.
Advantages:
a. Safe b. doesn’t need assistance
c. Convenient d. non- invasive
e. Economical f. painless
g. Avoidance of parental complication

21. Disadvantages
• Action is slow and thus not suitable for emergency
condition.
• Irritant and unpalatable drugs can’t be administered by
this route.
• May cause nausea and vomiting
• Cant be administered to uncooperative/unconsious and
vomiting patient.
• Drugs likely to be destroyed by digestive juices cant
administered orally. Eg insulin, penicillin.
• The absorption of certain drugs is irregular or negligible.
Both solid dosage forms(powder, capsule, tablet etc ) and
liquid dosage forms(elixirs, syrups, emulsions, mixture)
can be given by this route.

22. 2. Sublingual and buccal:
 Medication (tablet and pellet form) is placed under the tongue and is
allowed to dissolve in the mouth.
 Thus active agent gets absorbed into the systemic circulation
Buccal route: some of the drugs placed against the mucous membrane of
the buccal cavity in either upper or lower jaw.
Later these drugs gets absorbed slowly from the mucous membrane and
used mainly for local effect rather than systemic effect. Lozens and
troches are given from this route.
Advantages :
 Rapid onset of action
 Quick termination of the drug effect by spitting the tablet
 Degradation of the drug in the stomach is avoided.
Disadvantages :
 Inconvenient
 One can spit the drug before desire effect of drug is obtained
drugs used in this routes
Drugs used in this routes:
Nitroglycerine, Isoprenaline, methyltestosterone, clonidine.

23. 3. Rectal Routes:
Certain irritant and unpleasant drugs can be put into rectum as
suppositories or retention enema for systemic effects.
Advantages :
• Can be used in patient who can’t take orally.
Disadvantages :
 Inconvenient
 Embarrassing
 Absorption is slow, irregular and often unpredictable
 Inflammation of rectal mucosa
Drugs used in this routes are:
a. Aminophyline b. indomethacin
c. Paraldehyde d. paracetamol
e. Diazepam etc

24. 4. Transcutaneous:
Iontophoresis : galvunic current is used for bringing about
the penetration of drugs into the deeper tissues where
they may act upon the tissues in the neighbourhood of
the point of application.
Inunction: certain drugs when rubbed into skin can get
absorbed and produce their systemic effects.
Eg Nitroglycerin ointment in angina pectoris.
Adhesive units : A transdermal therapeutic system in the
form of an adhesive unit has been developed to deliver
drugs slowly, producing prolonged systemic effect.
Transdermal patches of nitroglycerin , nicotine and estradiol
are available.

25. Iontophoresis

26. Illustration of a transdermal drug delivery system

27. • Advantages :
 Provides smooth plasma concentration of the
drug without fluctutation.
 Minimise inter individual variations.
 More convenient
 Better complaint
• Disadvantages:
 Local irritation
 Erythema

28. 5. Inhalation:
i. Volatile liquids and gasses are given by inhalation for
systemic action eg: general anesthetic agent.
ii. Drugs are administered as nebulized particles from solutions
or in the forms of vapour.
iii. They may be sprayed as fine droplets which get deposited
over the mucous membrane producing local effects as well
as systemic effects.
Advantages
 Action is very rapid
 Controlled administration is possible
Disadvantages
 Irritation to mucous membrane
 Increased secretion in respiratory tract

29. 6. Nasal route:
Only certain drugs like vasopressin, hormone of posterior
pituitary gland is administered by this route
7. Parentral route:
Routes of administration other than the alimentary tract
(enteron).
Advantages:
• Action is faster and accuracy of doses are ensured.
• Gastric irritation and vomiting are not provoked.
• Can be used in an unconscious or an uncooperative
patient.
• Can be used in case of vomiting and diarrhoea
• Can be used in the patient unable to swallow
• Liver is bypassed

30. • Disadvantages:
 Less safe
 More expensive and inconvenient
 Self medication is difficult
 Preparation has to be sterilized
 Invasive technique and painful
 Injury to important structures eg: nerves and blood vessels
The important parentral routes are mentioned below.
a. Intradermal injection:
- Injected into the skin layers.
- Used for specific purpose only. Eg: BCG vaccination, drug
sensitivity test.
- A 1-ml syringe with a 25 to 27 guage needle ( length of needle ¼ to
5/8 inch) is used

31. b. Subcutaneous injection
• The drug is injected in the loose subcutaneous tissue
which is richly supplied by nerve but is less vascular, so
irritant drug cant be administered by this route.
• Insulin and heparin via this route.
• Common sites are upper abdomen, upper thigh and
upper back.
• A vol.of 0.5 to 1ml is used for this site.
• If more than 1 ml is indicated in this route it should be
divided in multiple sites with different needles and
syringe.
• A syringe with a 23 to 25 gauge needle that ½ to 5/8
inches in length is most suitable.

32. Special form of subcutaneous routes
• Dermojet:
o High velocity of jet of drug solution is projected from a microfine
orifice using a gun like implement.
o Doesn’t require the use of needle , therefore painless and suited
for mass inoculations
• Pellete implantation:
o Drug as solid pellet is introduced with a trochar and cannula
o Provides sustained release of the drug over weeks and months. Eg
DOCA, testosterone
• Sialistic (non biodegradable) and biodegradable implants:
o Crystalline drug is packed in tubes made of suitable materials and
implanted under the skin .
o Slow and uniform release of drug and maintained constant plasma
level.
o Eg: Norplant is the commonest agent which is used
subcutaneously as a temporary contraceptives.

33. Dermojet

34. c. Intramuscular injection
• The drug is injected onto the skeletal muscle eg: deltoid,
triceps, gluteal maximus, rectus femoris etc
• The rate of absorption is reasonably uniform and more rapidly
than S.C route because of rich blood supply in the muscles.
• A vol. of administered drug is more than 3ml, it is better to
give in two separate injections
• 22 guage needle is used.
Advantages:
 Soluble substances, mild irritants, suspension and colloids can
be injected by this route.
 Absorption is faster than subcutaneous route
 Less painful than SC route.
 Depot preparation can be used.

35. • Disadvantages :
 local pain
Local abscess formation at the site of injection
Injury to blood vessels, and nerve
Note:
Intramuscular in gluteal and deltoid should not be
given to the children until they start walking.
For these, vastus lateralis muscles is used for I.M
injection.
Gluteal muscles and deltoid are thin and are not
developed in this age group infants & children.

36. D. Intravenous route:
• Injected directly into vein producing rapid action, and desired
blood concentration can be obtained with a well defined
dose.
• A drug given intravenously may be injected:
 as bolus
 Infused slowly
 Given slowly over 5-10 minutes
Advantages
 100% bioavailability
 Can be given an irritant drugs
 Effects are obtained immediately
 Response is accurately measurable
 Titration of dose is possible.

37. Disadvantages
• Infection: systemic as well as local like thrombophlebitis
• High risk of toxicity
• No depot preparation for this route.
• More technical and costly
• Inconvenient to patient
• Difficult to self mediation.
E. Intra-arterial route:
 Drug is injected directly into artery which produces a
sudden high concentration in arterial blood stream
 Hence, may be harmful locally or damaging to tissues
supplied by the artery .
 It has only diagnostic role.

38. F. Intrathecal route:
 Drug administration into subarachnoid space.
 Spinal anaesthetic agents are given in this
route.
 It is more technical and used only in central
hospital.
G. Intra-articular route:
Drugs administration into the joint cavity
directly for local condition steroids are given
into the joint cavity for inflammatory joint
condition

39. H. Intra- medullary route:
Introduction of drug into bonemarrow.
I. Intra peritoneal route:
Introduction of the therapeutic agent into a
peritoneal cavity.

41. Thank you