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INTRODUCTION TO PHARMACOLOGY

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When the drug is administered into the body what happens with that drug? is studied under pharmacology. When the drug is administered, What the drug does to the body? (Pharmacodynamics) and What the body does to the drug? (Pharmacokinetics) is studied under Pharmacology.

Pharmacology is a branch of medical science where it deals with interactions of externally administered chemical molecules (Drugs) with living system.

It provides all the sense of knowledge about the drug, what is the effect of drug? as well as what our body does to the drug? It is both a basic and an applied science.

Thousands of years ago, many natural drugs were known. Many physicians were using the crude drugs, the therapeutic effect was seen but the mechanism of action (how the drugs work) was not known.

Now in recent times, many researches were conducted and also the drugs were studied thoroughly, they were classified, potency of drugs was studied, target of drugs along with its mechanism of action were studied.

This gave a broad spectrum to understand the concept of drugs. All this took place due to development of this field.

What you get below?

  1. Abbreviations
  2. Definitions
  3. Historical landmarks
  4. Nature and sources of drugs
  5. Essential drug concept
  6. Orphan drugs
  7. Prescription and non-prescription drugs
  8. Conclusion
  9. Frequently Asked Questions (FAQs)

Abbreviations used in Pharmacology

ADME: Absorption, Distribution, Metabolism, Excretion.
CDC: Centers for Disease Control and Prevention.
CDER: Center for Drug Evaluation and Research.
FDA: U.S. Food and Drug Administration.
HMG CoA: 3-hydroxy-3-methylglutaryl coenzyme A.
IND: Investigational New Drug.
LDL: low density lipoprotein.
NDA: New Drug Application.
NIH: National Institutes of Health.
NMEs: New Molecular Entities.
NMR: Nuclear magnetic resonance.
R&D: Research and development.

Definitions

Pharmacology:

Pharmacology is derived from two Greek words “Pharmacon” means drug and “logos” meansdiscourse in’. It deals with interactions of externally administered chemical molecules (Drugs) with living body.

Pharmacology provides all the advanced knowledge about drugs that gives safe, expected and also unexpected therapeutic effect in the living system.

This also deals as, What our body does once drug is administered ? And What the drug does to our body once it reaches internal environment of our body ?

Pharmacodynamics:

Pharmacodynamics is derived from two Greek words “Pharmacon” means ‘drug’ and dynamis means power. – ‘What the drug does to the body’. It includes physiological and biochemical effects of drugs and also their mechanism of action at every stage of living particles in body.

Pharmacokinetics:

Pharmacokinetics is derived from two Greek wordsPharmacon means drug andkinesismeansmovement. – ‘What the body does to the drug’. It includes movement of drug into the body and various it’s ADME i.e. Absorption, Distribution, Metabolism and Excretion.

Drugs:

Drug is derived from a French word “Drogue” means ‘a dry herb’ According to WHO (1996) “drug is any substance or product that is used or is intended to be used to modify or explore physiological systems or pathological states for the benefits of the recipient.”

Pharmacotherapeutics:

Pharmacotherapeutics is the use of pharmacological knowledge of drug and disease to prevent and also mitigate and cure the disease.

Clinical pharmacology:

Clinical pharmacology is the study of drug in human body. This includes Pharmacodynamic and pharmacokinetic study of drug in man and also their therapeutic and adverse effect related to physiology of body.

Pharmacy:

Pharmacy is the art and science of compounding and dispensing drugs or preparing suitable dosage forms for administering of drugs to man as well as animal.

Toxicology:

Toxicology is study of poisonous effect of drug and chemical with their identification, prevention, and also treatment of poisoning.

Historical landmarks

ContributorsContribution
Hippocrates (460 B.C -377 B.C)The Father of Medicine.
DhanvantariIndian medical practitioner and regarded as source of Ayurveda.
SusrutaAncient Hindu medical book author.
William Withering(1741- 1799)Discovered Digitalis.
Friedrich WohlerSynthesized Urea from inorganic substances.
Grieger and Hessie (1833)Discovered Atropine.
Vogt (1907)Discovered Histamine.
Abel (1919)Discovered Oxytocine.
A. Flemming (1928)Discovered Penicillins.
Waksman (1944)Discovered Streptomycin.

Nature and sources of drugs

SourceSpecific source/ DrugsNature
PlantsAtropa belladonna: Atropine
Foxglove: Digitalis
Anti-cholinergic

Cardiac glycoside
AnimalPork, Beef: Insulin
Horse: Tetanus antitoxin
Various animal: Heparin
Anti-diabetic

Anti-tetanus

Anti-coagulant
MicrobesPenicillium notatum: Penicillin

Actinomycetes: Strptomycin

E coli: L-asparaginase
Anti-biotic


Anti-biotic


Anti-cancer
MineralsGold

Magnesium sulphate

Aluminium hydroxide
Anti-arthritic

Purgative

Antacid
SyntheticAspirin


Cimetidine
Anti-inflammatory
Acid reducing agent

Essential Drug Concept

The WHO has defined Essential Medicines (Drugs) as “those that satisfy the priority healthcare needs of the population.”
Essential drugs are those which are first line treatment because they are in use as first choice of drug for the treatment.

It is also found out that only a handful of medicines out of thousand of drugs available can fulfill the majority health care needs of the people in any country and also this is a major concern in Pharmacology.

The drugs are selected keeping in the mind of public health relevance, safety, adverse effect, efficacy, and also its cost effectiveness.

These drugs are made available in all available stores as the first line treatment drugs and also in adequate amount.

The WHO has put forth some criteria to guide selection of essential medicines:


(a) Choice may influence by comparative pharmacokinetic properties and local facilities for manufacture and storage.

(b) Enough data on its efficiency and safety should be available from pre-clinical and also clinical studies.

(c) It should be available in the form in which quality, bioavailability, but stability on storage can be assured and should be main concern.

(d) Essential medicines should be selected in a continuous Manner.

(d) Most essential drugs/ medicines should be single compounds that is single chemical moiety.

(e) Choice should be dependent upon pattern of prevalent diseases and also availability of facilities and also trained physicians; but financial availability; genetic, geographical and environmental factors also should be taken care of.

(f) When choice should be made between two similar drugs, drugs should be chosen on the basis of their relative efficacy, safety, quality, price and availability. Cost-benefit ratio should be a major consideration as well.

(g) Eventually, it has been emphasized to select essential medicines based on rationally developed treatment guidelines.

WHO and India’s List of Essential Drugs:-

WHO has brought out its first Model List of Essential Drugs in 1977 that could be used with certain modification according to local need. This has been revised from time to time and the current is the 21th list (2019) which has 460 medicines.
India produced its National Essential Drugs List (NEDL) or National Essential Medicines List (NEML) in 1996, and has revised it in 2011, and meanwhile in 2015 with the title “National List of Essential Medicines”(NLEM). The latest list includes 376 medicines, of which 20 are FDCs (fixed dose drug combinations). Medicines in NLEM are listed as Primary (P), Secondary (S) and Tertiary (T) as a result of their level of healthcare.

Orphan drugs

These are drugs or biological products for diagnosis, treatment moreover prevention of a rare disease or diseased condition or a more common disease for which no reasonable expectation that the cost of developing and marketing it will be recovered from the sales of that drug.
Some of the orphan drugs for example are:-
Azacitidine, Busulfan, Carboprost, Clofazimine, Colchicine, Calcitonin, Digoxin antibody, Protamine sulphate, Rifaximin, Sodium nitrate, Sodium thiosulphate, and also Fomivirsen.

Prescription and non-prescription drugs

Prescriptionised drugs are those drugs such as for buying them a patient needs prescription of a registered medical practitioner. These drugs can not be sold by a pharmacist directly to the patient without a prescription and also These drugs are referred as scheduled H under drugs and cosmetic rule.

Non-Prescriptionised drugs are those drugs such as which can be bought by any store without any prescription. These are also known as over-the-counter’ (OTC) drugs.

Conclusion

As we have learned above, In conclusion Pharmacology is everything related to drugs and its response towards our body and our body’s response towards the drugs that we have administered (Ingested).

Component of Drugs involve Powders (The drug is in a dry and finely pulverized state) further it forms Tablet (powder mixed with adjuvant and blending agent).

Types of tablet for example involve Chewable tablets, Dispersible tablets, Sublingual tablets, Enteric coated tablet, Sustained/Extended release tablets, Controlled release tablets.

     Many ways of medications for example involve Pills, Lotions, Lozenges, Injections, Gels, Pressurized metered dose inhalers, Capsules, Elixirs, Suspensions, Drops, Suppositories, Ointments, Pastes ,etc.

Frequently Asked Questions (FAQs)

1) Why is pharmacology important?

It is important because it give knowledge about the drugs to be given for particular disease. It provides knowledge about the mechanism of action of the drugs for instance how it works.

2) Who studies pharmacology?

Anybody who is in the field of health care system can study pharmacology. The professionals or students for instance of MBBS, Pharmacy, and BDS study this subject in their curriculum.

3) Is their scope in pharmacology?

There is great scope in pharmacology, after all it the subject in the field of medical sciences and medical science is one of the highest grossing field in job sector.

4) Which book is best for pharmacology studies?

According to me, Essentials of Medical Pharmacology by K.D.Tripathi is the best book. Apart from this book you can refer Lippincott illustrated reviews:pharmacology is also referred by many students.

5) What is chemotherapeutics?

Chemotherapeutics is the treatment of malignant or systemic disease treated with specific drugs which have no or minimal effect on other cell except the infected cell.

6) Where can pharmacology graduate work?

Pharmacology is a subject in most of the health care studies. Along with it, it’s a specialization in MBBS and Pharmacy in masters.

7) Which university offer pharmacology subject?

Every medical college, every pharmacy colleges offer pharmacology subject.

8) Pharmacology or pharmacy?

Pharmacology is a subject in Pharmacy course, so I choose Pharmacy.

9) Pharmacy or Pharmaceutical science?

I choose Pharmacy because it a professional course.

10) Pharmacy or B.sc chemistry?

I choose B pharmacy, that is I have told you all B pharmacy is a professional degree course, here you get more knowledge and learn to apply the theory.

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