Introduction to Pharmacology
Content
General Pharmacology
•
Introduction
to Pharmacology
•
Historical landmarks
•
Scope of pharmacology
•
Nature and source of drugs
Intended Learning Outcomes
At the
end of this lecture, student will be able to
• Describe
Pharmacology
• Explain
the sources of drugs
• Discuss
the scope of pharmacology
Pharmacology
• Science
that deal with the drugs
• Derived
from Greek words
• Pharmacon
– An active principle/ drug
• Logos
– Discourse/ Study
• India
& China – Oldest known Pharmacological writings
• Vedas
– Earliest Indian records
• Rig
Veda – 3000 B.C
• Charaka,
Sushrutha, Vagbhata – Described various medicinal plants
• Charaka
• 300
herbal drugs
• Classified
to 50 groups
• Original
Ayurvedic Materia medica – superseded by alchemical/ Chemical substances in
Christian era
• Chinese
Materia medica – Pan Tsao
• Contained
plant, metallic and few animal preparation
• Modern
Medicine
• Date
(450 B.C) from Hippocrates, a Greek physician
• Concept
– pathologic process, observation, analysis
• Deduction
by medicine
·
Western Medicine
• From
Egypt, Assyria and Babylonia
• Papyri
– First written account of medical experiences from Egypt (1900 B.C)
• Homeopathy (Similar suffering)
• Concept
introduced by Hanneman in 19th century
• Like
cures like & dilution potentiates the action of the drug
·
Allopathy
(other suffering)
• Popularised
by James Gregory (1753-1821)
• Differs
from Modern Scientific medicine
• Wrongly
applied
Drug
• Derived
from French word drogue – a dry herb
• Drug
is defined as any substance used for the purpose of diagnosis, prevention,
relief/ cure of a disease in man/ animals
• According
to WHO
A drug
is any substance / product that is used or intended to be used to modify/
explore physiological systems/ pathological state for the benefit of the
recipient
Allied
topics of Pharmacology
• Pharmacognosy
• Pharmacy
• Clinical
Pharmacy
• Pharmacokinetics
• Pharmacodynamics
• Pharmacotherapeutics
• Toxicology
• Chemotherapy
• Pharmacoepidemiology
• Pharmacoeconomics
• Pharmacovigilance
• Pharmacogenetics
• Pharmacogenomics
Pharmacopoeia
• Offical
code containing selected established list of drugs
• Descriptions,
sandards
• IP,
BP, USP, Ph. Eur.
Formulary
• Information
about available drugs
• Based
on original and reputed drug information sources
• WHO
Model Formulary: Help countries to develop national formulary
• The
British National Formulary: BMA & RPS
The Nature and Source of Drugs
• Mineral: Liquid paraffin, MgSo4, Mg
trisilicate, Kaolin
• Animal: insulin, thyroid extract,
heparin, Gn, sera
• Plant: Morphine, digoxin, quinine,
atropine, reserpine
• Microorganism: Penicillins
• Synthetic: Analgesic, hypnotic,
anticancer, antimicrobials
• Genetic engineering: Insulin, GH (rDNA)
• Hybridoma technique: Monoclonal Abs
Schedule
• Schedule I
– High
potential for abuse, research
– Cannot
be prescribed
– Research
– LSD,
Marijuana
• Schedule II
– High
potential for abuse (Physical and psychic dependence)
– No
telephonic prescriptions (not refillable)
– Morphine,
codeine
• Schedule III
– Accepted
medical use with restrictions
– Ketamine,
thiopental, nalorphine
• Schedule IV
– Low
abuse potential
– Long
acting barbiturates and benzodiazepines
• Schedule V
– Minimum
abuse
– Some
on prescription – Codeine
– Others
– OTC
Summary
• Pharmacology:
Science that deals with the drugs
• Concept
– pathologic process, observation, analysis
• Pharmacology is the branch of
biology concerned with the study of drug action, where a drug can be
broadly defined as any man-made, natural, or endogenous molecule which exerts a
biochemical or physiological effect on the cell, tissue, organ, or
organism
