Introduction to pharmacology

Question 1

Define pharmacology?

Answer 1

Pharma: means drug or poison
Logy: Is the study
Pharmacology is the study of actions of drug on living organisms including chemical and physical properties, biochemical and physiological effects, mechanism of actions, therapeutic uses and adverse effects, of the drugs.

Question 2

What are drugs?

Answer 2

Drugs are derived from the french word Drouge (dry herbs)
Drugs are chemicals that effects the processes of living organisms

Question 3

What are the sources of drugs?

Answer 3

There are two sources of drugs.
1. Natural Sources
2. Synthetic

Question 4

What are natural source drugs?

Answer 4

1. Plants: morphine, atropine, digoxin, quinine
2. Animals: Insulin, heparin, antitoxic sera
3. Minerals: MGSO4, gold, iron, sulphur
4. Microorganisms: Cephalosporins, tetracycline, penicillin
5. Humans: Immunoglobulins, growth hormone

Question 5

Synthetic source of drugs

Answer 5

Obtained from cell culture, recombinant DNA technology
Eg: Quinolones, Omeprazole, sulfonamide

Question 6

Nomenclature of the drugs

Answer 6

1. The chemical name: it is the technical description of the actual molecule and also referred as IUPAC id
2. The generic name or the non property name: Official medical name accepted by the competent scientific body
3. The brand name: The name assigned by the manufacture and the name in which the product is marketed

Question 7

What is pharmacokinetics?

Answer 7

It means what body does to the drug or the quantitative study of drug movement in, through and out of the body by following processes: Absorption, distribution, metabolism and excretion also bioavailability.

Question 8

Wat is absorption

Answer 8

It is the movement of drug from the site of administration to the circulation (speed of drug action = rate of absorption)

Question 9

What determines absorption?

Answer 9

1. Aqueous solubility
   rate of dissolution governs rate of absorption except in drugs given through IV
2. Concentration
   Passive transport depends on concentration. Drugs given in concentrated solution absorbs faster than the drugs given in dilute solution
3. Area of absorbing surface
   Larger the surface area, faster the absorption
4. Vascularity of absorbing surface.
   Increased blood flow hastens the absorption
5. Route of administration
   Fastest (Liquid, elixirs, syrup) Slowest (Enteric coated tablets)

Question 10

Bioavailability

Answer 10

Refers to the rate and extent of abasorption of administered drug from ints dosage form determined by circulation time curve in the blood and excretion in urine
It is also the measure of fraction of administered dose of drug that reaches the systemic circulation in unchanged form

Question 11

What is distribution

Answer 11

When the drug reaches the pblood system, it gets distributed to the other tissues.
Concentration gradient being from plasma to tissue.

Question 12

What is the extent of distribution determined by

Answer 12

Lipid solubility
Ionization of physiological pH
Extent of binding of plasma and tissue proteins
Differences in regional blood flow
Body mass ratio and disease conditions

Question 13

What is metabolism

Answer 13

Metabolism is also known as biotransformation and it means chemical alterations of drug in the body
An essential pharmacokinetic process is that it needs to make lipid soluble and non polar compounds into water soluble and polar compounds so they are excreted by various process from the body

Question 14

What is the primary and other side of metabolism?

Answer 14

Primary side of metabolism is LIVER and others are plasma, kidney, intestine and lungs

Question 15

What does metabolism lead to?

Answer 15

1. Inactivation
2. Active metabolite from active drug
3. Activation from an inactive drug

Question 16

First Pass Metabolism

Answer 16

Phenomenon of drug metabolism at a specific location in the body which leads to the reduction in the concentration of the active drug before it reaches the site of action

Question 17

What is excretion?

Answer 17

Excretion means removal of medication from the body

Question 18

what is t1/2 life

Answer 18

time taken for the plasma concentration of the drug to reduce to half of it’s value

Question 19

significance of t1/2 life

Answer 19

1. Duration of action of drug
2. Frequency of administration
3. Time needed for action - steady state concentration
4. To calculate loading and maintenance doses

Question 20

What is biological half life

Answer 20

It is the time required for total amount of drug in the body to be reduced to half.

Question 21

What is drug dose

Answer 21

it is an appropriate amount of drug needed to produce a certain degree of response in a patient

Question 21

Factors determining dosage

Answer 21

1. Age
2. Sex
3. Body weight and surface area
4. Specific disease conditions
5. Half life
6. Tolerance

Question 22

What is pharmacodynamics?

Answer 22

What drug does to the body.
IT includes the physiological and biochemical effects of drugs and their mechanism of action

Question 23

what are the principles of drug actions or pharmacodynamics

Answer 23

1. Irritation
2. Depression
3. Stimulation
4. Cytotoxic action
5. Replacement

Question 24

What are the mechanisms of drug action

Answer 24

Physical action - Absorptive property of charcoal
chemical action - chelating, acidifying, alkalinizing
through enzymes - enzymes are important target of drug action through either inhibition or stimulation
Through receptors - drugs chemically bind to specific site receptor sites

Question 25

What are agonist, antagonist and partial agonist

Answer 25

Agonist - Drug fits at receptor site well
Antagonist - Chemically block another chemical from getting to a receptor
Partial agonist - Attach to the receptor but only provide small effect

Question 26

What are the basic drug action

Answer 26

Desired action - expected response of the medication
Side effects - Known and frequently experienced or expected reactions to the drug
Adverse effect - Unexpected, unpredictable reactions that are not related to usual effect of normal dose of the drug

Question 27

What is adverse drug reactions or ADR?

Answer 27

Are any reactions that is unexpected, undesirable and occurs doses normally used and are not preventable

Question 28

Roles of nurses in ADR