This presentation contains all answers of 2 mark in chapter 1 pharmacology- I 2nd year PharmD RGUHS question bank.

1. RGUHS SOLVED QUESTION BANK SERIES
PHARMACOLOGY-I
CHAPTER-1
GENERAL PHARMACOLOGY
2 MARKS

2. 1. Define Prodrug

3. ● The term ‘Prodrug’ was introduced in 1958 by Adrien
albert.
● It is a medication or compound that after administration
is metabolised (i.e. converted within body)
pharmacologically active drug.
● It is a drug which doesn’t produce any pharmacological
effect (not active) until it is chemically altered within
the body.

4. ● It is defined as a biologically inactive derivatives of a
parent drug molecule that usually requires a chemical or
enzymatic transformation within the body to release the
active drug & possess improved delivery properties over
the parent molecule.
Levodopa Dopamine (active form)
(Prodrug)
(Inactive forms)
decarboxylase

5. ● They are often designed to improve bioavailability when
a drug itself is partially absorbed from GIT.
● It may be used to improve how selectively the drug
interacts with cells or process that are not its involved
target.

6. 2. Define First pass effect

7. ● The first pass effect is also known as first pass
metabolism or presystemic metabolism.
● It is a phenomenon of a drug metabolism whereby the
concentration of a drug is greatly reduced before it
reaches the systemic circulation
● Orally administered drugs are absorbed from GI tract.
The blood from the GI tract then travels via the liver.

8. ● Many drugs that undergo liver metabolism will be
extensively metabolized during this passage from the GI
tract to the body.
● This effect of liver metabolism is called First pass effect.
● The drugs which experience significant first pass effect
are Propranolol, Lidocaine & Nitroglycerine.

9. 3. Define Therapeutic index

10. ● The therapeutic index of the drug is the ratio of the dose
that produce the toxicity to the dose that produce a
clinically desired or effective response in a population of
individuals.
TI =
● LD50- median lethal dose
● ED50- median effective dose
LD50
ED50

11. 4. Define Bioequivalence

12. ● It refers to two or more drugs forms of the same drug
reach the blood circulation at the same rate & same
relative extent, they are called bioequivalent
preparations of the generic drug.
● Eg: A receptor in the brain - the brand name & the
generic drug should deliver the same amount of active
ingredient to the target site.

13. ● If two formulations of a drug have some bioavailability,
they are bioequivalent.
● Comparison of bioavailability of different formulations of
the same drug is the study of bioequivalence.
● Often oral formulations containing the some amount of a
drug from different manufactures may result in different
plasma concentrations, or may differ in the rate of
absorption.

14. 5. Explain Child dose
calculation

15. ● Age: Dose calculation related to age.
i. Young’s formula
Child’s dose = x Adult dose
ii. Dilling formula
Child’s dose = x Adult dose
iii. Fried’s rule
Child’s dose = x Adult dose
Age(year)
Age(year)+12
Age(year)
20
Age(month)
150

16. ● Body Weight: Dose calculation related to body weight.
i. Clark’s formula
Child’s dose = x Adult dose
ii. Dilling formula
Child’s dose = x Adult dose [1kg= 2.2 lb]
● Surface area: Dose calculation reLated to SA
Child’s dose = x Adult dose
Body weight(lb)
150
Body weight(kg)
70
Child’s body S.A
Average adult’s
body S.A

17. 6. Define cross tolerance
with example

18. ● It is defined as a specific type of drug tolerance that is
formed via continued use of another drug with similar
effects.
● It is phenomenon in which repeated use of a drug in a
given category confers tolerance not only to that drug
but also to other drugs in the same structure.
● Eg: Barbiturates ⇔ Benzodiazepines

19. ● It happens often between two drugs with similar
functions or effect.
● Eg: i. Acting on same cell receptors or affecting the
transmission of certain neurotransmitters.
● ii. Alcoholism often develop a higher tolerance for anti-
anxiety medication such as xanax & valium than non-
alcoholism.

20. 7. Define iontophoresis and
its uses

21. ● The term Iontophoresis simply defined as ion transfer.
● It is a painless of delivery, sterile, non-invasive technique
of delivering medication via the skin by using a gentle
electric current.
● It is a medical device which uses mild electrical current
to deliver the medication across the biological
membrane.

22. ● It is the process of transdermal drug delivery by use of
voltage gradient on the skin.
● Uses:
i. Treatment of hyperhidrosis
ii. Delivery of local anesthetics, steroids, etc
iii. Delivery of metallic & non- metallic ions

23. 8. What are the different
source of drugs?

24. ● Drug are obtained from different sources namely
i. Plants (alkaloids, glycosides, oil)
ii. Animals
iii. Microbes
iv. Minerals
v. Synthetical chemistry
vi. Biotechnology

25. ● Plants:
Many plants contain biologically active substance &
are the source of drugs
Eg: Morphine, Nicotine, Digitoxin
● Animals source:
Compounds consists of heterocyclic non- sugar
moiety.
Eg: Digoxin, Gentamicin

26. ● Microbes:
Most antibiotics obtained from fungi, bacteria &
actinomycetes.
Eg: penicillin
● Minerals:
Few minerals are used as medicine substances
Eg: iron salts, calcium salts, lithium carbonates,
iodine.

27. ● Synthetic chemistry:
Here drugs are synthetically & purity, uniformity of
the products can be expected.
Eg: thiazides, benzimidazoles
● Biotechnology:
Several drugs like peptides and proteins are now
produced by recombinant DNA technology
Eg: Human growth hormone , human insulin.

28. 9. Define Drug dependence
& Drug abuse

29. ● Drug dependence:
It is a state of a psychic & a permanent physiological
change causing an individual to persistently crave the
consumption of particular substance to avoid
discomfort of its absence.
It is also known as drug addiction.
Drug producing dependence are opioids, barbiturates,
& other depressants including alcohol & benzodiazepines.

30. ● Drug dependence:
These drugs influence the behaviour & mood or often
misused to obtain pleasurable effects.
Dependence could be “ psychological” or “physical”
dependence.
Psychological dependence - compulsive drug seeking
behaviour to obtain its pleasurable effects.
Eg: cigarette smoking.

31. ● Drug dependence:
Physical dependence- present when withdrawal of the
drug produces adverse symptoms causes “withdrawal
syndrome”.
Eg: alcohol, opioids, barbiturates.
Mild degree of physical dependence is seen in people
who drink too much of coffee.

32. ● Drug abuse:
It is a self administration of a drug for non-medical
reason in quantities & frequencies which may impair
an individual's ability to function effectively & may
result in social, physical or emotional harm.

33. ● Drug abuse:
It is a self administration of a drug for non-medical
reason in quantities & frequencies which may impair
an individual's ability to function effectively & may
result in social, physical or emotional harm.

34. 10. Explain Tachyphylaxis

35. ● Tachy- rapid
phylaxis- protection
● It is refers to the rapid development tolerance when
doses of a drug repeated in quick succession result in
marking reduction in response.
● This usually seen with indirectly acting drugs such as
ephedrine tyramine, nicotine.

36. ● These drugs act by releasing catecholamines in the body,
synthesis of which is unable to match the rate of release
or stores get depleted.
● Mechanisms of tolerance-
1. Pharmacokinetics/ drug disposition tolerance
2. pharmacodynamics/ cellular tolerance

37. 11. What are Adverse drug
reactions? Give Example.

38. ● Adverse drug reaction is defined as any change which is
suspected to be due to a drug occurs normally in doses
used, required treatment or decrease in dose or
indicates the caution in the future use of the same drug.
● It is divided into 2 type
- Predictable reactions
- Unpredictable reactions

39. ● Eg:
Anticoagulant- Bleeding
Paracetamol- hepatotoxicity
Beta blockers- bradycardia

40. 12. Define Apparent volume
of distribution

41. ● Apparent volume of distribution is defined as the total
amount of drug in the body.
● Presuming that the body behaves as a single
homogenous compartment with volume
V (or) aVd =
Total amount of drug in the body
Conc. of the drug in plasma

42. 13. Define Additive effects
with examples

43. ● Additive effect is defined as combined effects of drugs which
are given simultaneously is equal to the sum of magnitude of
effect produced by individual drugs.
● The effect of the two drugs is in the same direction & simply
adds up:
Effect of the drugs A + B = Effect of drug A+ Effect of drug B
● The combination is better tolerated than higher dose of one
component.

44. ● Examples:
Aspirin + paracetamol as analgesic/ antipyretic.
Glibenclamide + metformin as hypoglycemic.
Ephedrine + theophylline as bronchodilator.

45. 14. Define synergistic
effects with examples

46. ● An interaction between two or more drugs that causes the total
effect of the drugs to be greater than the sum of the individual
effect of each drugs.
● Example: The potency of Aspirin and caffeine increases when
combined providing greater pain relief than when taken alone.

47. 15. Enlist Cholinergic
receptors

48. This question belongs to the
second chapter.
So it will be included in the next
chapter.

49. 16. Define Dose response
relationship

50. ● When a drug is administered systemically, the dose response
relationship has 2 components,
1) Dose plasma concentration relationship
2) Plasma concentration-response relationship.
● The former is Determined by pharmacokinetics consideration &
ordinary description of dose response relationship refer to the
latter which can be more easily in vitro.

51. 17. Merits & Demerits of
Intrathecal route of
administration

52. Merits:
● It allows drug administration to CSF by the blood brain barrier.
● It can decreased side effect because directly administered into
the CSF.
● It can be reversible if intervention is not beneficial.
● It has high potency than oral medication.

53. Demerits:
● It can cause drug induced aseptic or chemical meningitis due
to direct imitation of the meninges of the drugs.
● Constant maintenance is required.
● It can cause the development of intrathecal granuloma.

54. 18. Define Competitive
antagonism with example

55. ● In competitive antagonism, antagonist binds with the same
receptors as agonist.
● If the log dose response curve with agonist is obtained in the
presence of antagonist, it will be found that antagonist has no
effects on its own & there is parallel rightward shifts in the
dose response curve of agonist with no change in shape, slope
for maximum response.
● Example: Acetylcholine ( as agonist)
Atropine ( as antagonist)

56. 19. Define non-Competitive
antagonism with example

57. ● The antagonist is chemically unrelated to the agonist
bind to a different allosteric site altering the receptors
in such a way that it is unable to transduce the response.
● This is also known as allosteric antagonism
● Increasing concentration of the antagonist progressively
flatten the agonist.

58. 20. Define Placebo

59. ● This is an inert substance which is given in the grab of
medicine.
● It works by psychodynamic than pharmacodynamic
means & often produces response equivalent to the
active drug.
● Placebo are used in two situations:
1. As an control device in clinical trials of drugs.
2. To treat patients who doesn’t require active drug.

60. 21. Merits & Demerits of
nasal route of
administration

61. Merits:
● GIT is absent, hepatic first pass metabolism is absent, rapid
drug absorption & quick onset of action can be achieved.
● Bioavailability of larger drug molecules can be improved by
absorption inchanced, hence high bioavailability is there
● Drugs that are orally not absorbed can be delivered to the
systemic circulation by nasal drug delivery.
● It has reduced or almost no side effects.

62. Demerits:
● Nasal drug administration is linked to very small volumes &
thus only applicable to potent drugs which high water
solubility.
● Disease condition in nose may result in impaired absorption.

63. 21. Merits & Demerits of
sublingual route of
administration

64. Merits:
● Absorption is relatively rapid action can be produce in minutes
● The liver is bypassed & drug with high first pass metabolism
can be absorbed directly into systemic circulation.
● Action can be terminated by spitting out the tablet.
● Self administration is possible.

65. Demerits:
● Drug with bad taste can’t be given.
● Irritant & lipid insoluble drug can’t be taken via this route.