1 intro pharmaco drugs pdf

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GTB 214/3 Basic Pharmacology

Dr. Wan Ezumi Mohd Fuad


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Drugs / Medicines


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What is Pharmacology ?


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Pharmacology is a basic preclinical medicalsubject related to drugs/medicines.

Pharmacology


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Pharmacology

Pharmacology is a branch of medical science.

Pharmakon - Greek word means drug

Logos - Greek word means knowledge

So, Pharmacology is knowledge about drugs.

It is the study of how drugs modify biochemical,physiological and psychological processes in healthand disease.


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Pharmacology deals with the interactions

between drug & living body.

It is both a basic and clinically appliedscience.

Pharmacology


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As a basic science, it deals with

the fate & actions of drugs at various levels(molecular, cellular, organ & whole-body)

drawing of knowledge, concepts, & techniquesderived from biochemistry, physiology, biophysics,& other divisions of biological science.

Pharmacology


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As an applied science it deals

Specifically with drug-human body interaction

The use of drugs in the treatment of disease

Pharmacology


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Pharmacology includes:

Sources of the drugsProperties

Preparations

Dispensing

Administration of drugs in the body

Drug-body interaction

Effects & Mechanisms of action of drugs.

Pharmacology


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Divisions of Pharmacology


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Pharmacoepidemiology:

deals with

use of drugs

safety of drugs

Study of the utilization and effects of drugs in largenumber of people/patients.


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Pharmacosurveillance:

deals with

drug monitoring

safety of drugs

Branch of pharmacology which deals with the practice ofmonitoring a pharmaceutical drug or device after it hasbeen released on the market.


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Pharmacy:

deals with

manufacturing preparation of dosage form

dispensing of drugs.


Science of preparing and dispensing medicines.


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Therapeutics:

deals with

Use of drugs in living body for therapeutic purpose.

Therapeutics is the extension of the knowledgegained from pharmacology to the rational use of

drugs in the treatment of disease.



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Posology:

deals with

Dosage

Therapeutic effect

Study of the amount of drug that is required to producetherapeutic effects.


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Clinical Pharmacology:

deals with

Scientific study of drugs in human body.

Research & Clinical Trails

New drug development---phases



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Medical Pharmacology

deals with

Study of drug in human body



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Headache?.try one paracetamol!!


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And..get some relaxation!!


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Drug

Definition of drug according to WHO:

Any substance or product that is used orintended to be used to modify or explore

physiological systems or pathological

states for t he benefit of the recipient


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Drug

What is a drug?

A chemical substance

Given to human bodyFor the benefit of the recipient (patient)

What benefits?

Cure of a disease

Prevention of a disease

Suppression of a disease

Diagnosis of a disease


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Drugs are used for :

A) Cure of a diseaseAntibiotic cures bacterial infection

Paracetamol cures pain & fever

B) Suppression of disease

Insulin suppresses DM

Drug


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Drug

C) Prevention of a disease

Vaccines prevent diseases

Polio vaccine for preventing Poliomyelitis

D) Diagnosis of disease

Barium meal X-ray for diagnosis of peptic ulcer


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Drug and medicine

Drug

A drug is a single chemical substance that

forms the active ingredient of a medicine

Medicine

A mixture of substances used in restoring orpreserving health

A medicine contains the active ingredient plusexcipients


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Drug and medicine

Excipients:

As most drug are presented in small

quantities, sometimes less than a milligram,other materials must be added to make themeasy to administer.

Excipients are pharmacologically inactivesubstances which are mixed with the activeingredient (drug).


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Drug and medicine

Why excipients are used?

To make a stable, acceptable & convenient form

To make helpful to administer to patient

Example of Excipients:

Binders

Lubricants

Disintegrating agents

Flavoring agents

Coloring agents etc.


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Therefore,

Medicine = Drug (active ingredient) + Excipients

In pharmacology generally both terms (drug or

medicine) are used for the same purpose

Drug and medicine


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Criteria of Drug

A) Chemical nature

Drugs are generally weakly acidic or weaklybasic substance

Why not strongly acidic or basic?

Dissociates easily Highly corrosive, may cause injury


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Criteria of Drug

B) Size

Generally low molecular weight (100-1000 Da)

Some are of high MWinsulin 6000 Dalton

C) Shape

Usually complimentary to the shape of the receptorso that can easily bind.


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Drug sources

Natural Semisynthetic Synthetic

Sources of Drug


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Sources of Drug

Natural source

Plant

Animal

Mineral


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i) Plant source

Main source of drug from ancient time.

Alkaloids & Glycosides

Alkaloids:

Contains Nitrogen

Nitrogenous substances from plant source

Example:

Morphine from Opium seeds (Papaver somniferum)

Atropine from leaves of Atropa belladonna

Sources of Drug (Natural)


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Papaver somniferum


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Glycosides:

Does not contain nitrogen

non-nitrogenous substance from plant source Contains glucose

Example: Digitalis from Foxglove (Digitalis purpurea)



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Foxglove plant (Digitalis purpurea)


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ii) Animal source

Source from living animals

Example:Insulin from Pork (Porcine insulin), insulin fromCattle (Bovine insulin)

Penicillin from the fungus Penicillium notatum

iii) Mineral source

Iron, zinc etc.



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Penicillium notatum


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Sources of Drug (Semi synthetic /synthetic)

Semi synthetic drugs

Obtained by chemical modification of the purecompounds of natural sources

Example:

Heroin from Morphine

Penicillin V from Benzyl Penicillin

Synthetic drugs

New molecules synthesized in the laboratory

Example: Barbiturate, Sulfonamides etc.


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Name of the drugs

A drug is known by many names.

A) Chemical name

very difficult to remembere.g. N-(4-hydroxyphenyl)ethanamide

B) Generic nameOfficial name, common name

rINN (Recommended International Non-Proprietary name)

Same throughout the world


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Name of the drugs

C) Brand name

Proprietary nameTrade name

Different by different pharmaceutical companies


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Name of the drugsExample of names of a drug :

Chemical name: N-(4-hydroxyphenyl)ethanamide

Generic name: Paracetamol / Acetaminophen(USAN).

Brand name: Panadol, Uphamol, Milidon.


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Name of the drugs

Example of names of a drug :

Chemical name: 2-acetoxybenzoic acid

Generic name: Aspirin

Brand name: Disprin, Empirin etc.


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Advantages of using Generic name:

Easier to remember

Same throughout the world

Less chance of confusionEasily understood by all health professionals

Name of the drugs


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Types of Drugs

Normally drugs act in the body by binding withsome specific substance in the body.

These specific substances are known as receptors.

Drugs binding with receptors form a drug-receptor

complex After that a response is produced


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Types of DrugsDrug + Receptor {DR} complex

affinity

efficacy

Response


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Types of DrugsAffinity

The tenacity of a drug to bind with receptor

Efficacy The capacity of a drug to produce a response after

binding with receptor

** All drugs are not same in respect to their affinityand efficacy


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Types of DrugsAgonists:

The drugs which can bind with receptor and also

able to produce response after binding

They have both affinity & efficacy

Affinity + & Efficacy + = response


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Types of Drugs

Antagonists:

These are the drugs which can bind with

receptor but not able to produce response

They also inhibit the effect of agonists byoccupying the receptors

They have affinity but no efficacy

Affinity + & Efficacy - = no direct response

However indirectly causes response


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Types of DrugsPartial Agonists/Antagonists:

They bind with receptor and initially produce smallresponse like agonists but ultimately act asAntagonists.

Affinity +, Efficacy +/-


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Types of DrugsExamples

Morphine is an agonist drug

It binds with opioid receptorIt also produces response (analgesia)

Naloxone is an antagonist,

It binds with opioid receptor

Does not produce response (analgesia)

Prevents the effect of Morphine


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Types of Drugs

Examples

Nalorphine is a partial agonist

It initially acts like MorphineIt binds with opioid receptor and producesanalgesia (agonistic effect)

BUT

Ultimately acts as Naloxone

It blocks the opioid receptor and prevents the

action of morphine (antagonistic effect)

K


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Key terms

Therapeutic effect: Desired drug effect to alleviatesome condition or symptom ofdisease.

Side effects: Drug effect other than therapeuticeffect that is usually undesirable butnot harmful.

Adverse effects: Undesirable & potentially harmful drug

effect.Toxic effects: undesirable drug effect that implies

drug poisoning, can be harmful and lifethreatening.


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Best of luck!!!!!!

merci

1 intro pharmaco drugs pdf

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