Dr. Syed Shariq NaeemMBBS, MD, DNB, DCRP

Assistant Professor

• Introduction: Drug, Nomenclature, Sources & Discovery• Routes of Drug administration and Dosage Forms• Pharmacokinetics

I. AbsorptionII. DistributionIII. MetabolismIV. Excretion

• PharmacodynamicsI. Mode of action of DrugsII. Drug Receptor Interaction

• Drug Safety and Adverse Drug Reaction• Factors modifying drug action• Miscellaneous Topics

At the end of the discussion you should be able to understand:

• What is a Drug?

• How drugs are named?

• Sources of Drugs?

• Where will you get information about different drugs?

• What are Essential Drug and Orphan Drug?

• How a new drug comes to the market?

• Common routes of Drug administration

Drug

Old Definition:• Drug is a chemical substance used for the

treatment, cure, prevention or diagnosis of adisease in human beings or animals.

New Definition:• Any substance or product that is used or intended

to be used to modify and explore physiologicalsystems or pathological states for the benefit ofthe recipient.

Sub- Branches of Pharmacology

Pharmacogenomics Pharmacoeconomics

Pharmacognosy

Pharmacoepidemiology Ecopharmacology

Drug

ParacelsusFather of Toxicology,

Swedish Physician (1493)

All things are poison and nothing is without poison; only the dose makes a

thing not a poison."

Sources of Drugs

A Short History of Medicine“I have a Earache”

➢ 2000 BC: Here eat this root.

➢ 1000 AD: Root is heathen. Say this prayer.

➢ 1850 AD: That Prayer is superstition. Here drink this potion.

➢ 1940 AD: That potion is snake oil. Take this pill

➢ 1985 AD: That pill is ineffective. Take this antibiotic.

➢ 2017 AD: That antibiotic is artificial. Here eat this root.

Types of Drug Names: 3

Drugs are classified and named into three types of names.

1. Chemical Name: ➢ Molecular/Scientific name

➢ Chemical or molecular structure of the drug.

➢ Problem: long and difficult to remember.

➢ Useful: To technically trained personnel who are involved in research.

Eg. 2-acetoxybenzoic acid is the chemical name of Asprin

2. Generic Name: ➢Non-proprietary or Approved name

➢Abbreviated and approved name of the drug.

➢Assigned by the producer in collaboration with the scientific nomenclature bodies like➢ WHO (International Non-proprietary Name- INN)

➢ USA’s (United States Adopted Names council- USAN).

➢Significance: Removes the confusion of giving several names to the same

– Eg. Acetylsalicylic Acid for Asprin

Generic Drugs

Advantages

• Low cost (some times very low cost)

• Same active compound as the branded drugs

Disadvantages• Some times the bioequivalent

drug isn't available in a generic version

• Bioequivalence range -80 percent below or 125 percent above the original drug’s range of bodily absorption. Therefore, even different generic forms of the same drug can vary greatly. This fluctuation can have a significant impact on the efficacy of a drug.

• Since generics vary so greatly, unknown or unlisted side effects could occur.

3. Trade Name: ➢Proprietary or Trade name

➢Names given by the manufacturing and marketing company

➢They are copyrighted: Prevent any other person from using the name.

Branded Drugs

Advantages

• Extensive testing and regulation involved in the research and production

• Efficacy and side effect profile well defined

Disadvantages

• High cost

• Causes confusion, leading to prescription error or consumption error by patient.

Different Names of the Drugs

S.No Generic Name Trade Name Chemical Name

1 Paracetamol Calpol N-acetyl-p-aminophenol

2 Ibuprofen Brufen (RS)-2-(4-(2-methylpropyl)phenyl)propanoic acid

3 Diphenhydramine Benadryl 2-(Diphenylmethoxy)-N,N-dimethylethylamine

hydrochloride

4 Azithromycin Zithromax (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-13-[(2,6-

dideoxy-3-C-methyl-3-O-methyl-α-L-ribo-

hexopyranosyl)oxy]-2-ethyl-3,4,10-trihydroxy-

3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-trideoxy-

3-(dimethylamino)-β-D-xylo-hexopyranosyl]oxy]-1-

oxa-6-azacyclopentadecan-15-one

Brand NameGeneric Name

Sources of Drug Information

Drug Compendia:

• Compilation of information on drugs in the form of monographs.

• Two Types

Official Unofficial

CIMS,MIMS

Martindale

Drug Compendia

Pharmacopoeias Formularies

Pharmacopoeias

• Contains structure, physical & chemical properties etc.

• Useful to manufacturers and regulatory body, NOT to doctors

• Eg. Indian Pharmacopoeia (IP),

British (BP), USA (USP)

Brand NameGeneric Name

PharmacopoeiaIP, USP, BP

Formularies

• They contains list of indications,contraindications, precautions, adverseeffects, storage etc.

• Useful for doctors

• Eg. National Formulary of India (NFI),

British National Formulary (BNF)

• Dose

• Dosage Form

Routes of Drug Administration

Brand NameGeneric Name

PharmacopoeiaIP, USP, BP

Dose Dosage Form

Routes of Drug Administration

• Enteral route➢Oral➢Sublingual➢Rectal

• Parenteral route➢Injection

➢IV, IM, Intradermal, Subcutaneous➢Intraarticular, Intrathecal, Epidural, Intracardiac

➢Inhalational ➢Transdermal

• Topical route

Intravenous route

Intramuscular Route

Subcutaneous Route

Intradermal Route