for nursing students

1. Pharmacology
Unit IV
Classification of Drugs
According to Action

2. Unit outcome
By the end of this unit students should
be able to explain the action of drug
by it’s classification

3. Content of the unit
1.Analgesics
2. Antipyretics
3. Antiseptics and disinfectants
4. Antibiotics
5. Anthelmentics
6. Antihistamins
7. Anti convulsives

4. Content of the unit
10 . Emetics
11. Antiemetics
12. Expectorants
13. Hypnotics
14. Myotics
15. Sedatives
16. Transquillisers

5. Introduction
• A chemical substance that
produces a biological effect when
administered to a living organism is
known as a drug in pharmacology.

6. Introduction cont...
• When these drugs are taken in the
prescribed manner to cure, prevent
or diagnose a disease, it is known as
medicine.

7. Introduction cont…..
• Based on the effects of drugs, they
are classified into four different
classes based on pharmacological
effect, drug action, chemical
structure, and molecular targets

8. Classification of Drugs
Drugs can be classified mainly based
on the following criteria:
• Pharmacological Effect
• Chemical Structure
• Molecular Targets
• Drug Action

9. Based on Pharmacological Effect
• Based on the action of drugs on our
body, they are classified based on
their therapeutic actions.
• Such as antacids reduce acidity in the
stomach, analgesics are pain killers,
antiseptics kill microorganisms, etc.

10. Based on Chemical Structure
• Based on the common chemical
structures, drugs are classified into
various classes.
• As chemical structures, functional
groups, etc., are responsible for
their chemical properties

11. Based on Chemical Structure cont...
• Mostly, drugs having similar chemical
structures show similar effects on
the body.
• For example, sulphonamide drugs,
barbiturates, etc.

12. Based on Molecular Targets
• Some drugs target protein,
carbohydrates, etc.
• Generally, drugs that have similar
structures target similar molecules in
our body and produce responses
accordingly

13. Based on Drug Action
• Drugs are also classified based on
their action on molecular targets
and effects on our body.
For example, histamines are
responsible for causing
inflammation in the body, and we
take anti-histamines to block their
actions.

15. 1. Analgesics
• The word analgesic derives from
Greek
an (without ) + Algos (pain)
• Drugs that selectively inhibit the
perception (sensation) of pain.

16. 1. Analgesics cont...
• Relives pain selectively without
blocking conduction of nerve
impulses, altering sensory
perception or affecting
consciousness.

17. Classification of analgesics
Analgesic are divided into two main
groups
1. Opioid analgesics
2. Non opioid analgesics

18. Opioid analgesics
• The opioid analgesics act on the brain
and can induce sleep.
• Opioids are once called narcotic drugs
• The opioid analgesics can be used for
either short-term or long-term relief of
severe pain
• There are three types

19. 1. Natural opium alkaloids
Ex:
• Morphine
• Codeine Methadone
• Hydromorphone

20. 2. Semi-synthetic opiates
• Diacetylmorphine
• Oxymorphone
• Pholcodeine

21. 3. Synthetic opioids
Ex:
• Pethidine
• Methadone
• Dextropropoxyphene

22. Non opioid analgesics
• NSAIDS (non-steroidal anti-
inflammatory drugs) / non narcotics
• Non opioid analgesics which alleviate
pain by reducing local inflammatory
responses.

23. Non opioid analgesics cont…
• The anti-inflammatory activity of
NSAIDs is based on the inhibition of
the cyclo-oxygenase (COX) enzyme,
resulting in prostaglandin synthesis
inhibition

24. Non opioid analgesics cont…
• In contrast, the anti- inflammatory
compounds are used for short-term
pain relief and for modest pain,
such as that of headache, muscle
strain, bruising, or arthritis.

25. Non opioid analgesics cont…....
Ex:
• Ibuprofen
• Diclofenac Sodium
• Indomethazine

27. 2. Antipyretic
• Antipyretic drugs are the drugs that
apparently resets the set point or
thermostats and also increase heat
loss through peripheral vasodilation by
inhibiting synthesis of prostaglandins.
• They reduce body temperature in
fever but do not cause hypothermia in
normothermic individuals.

28. Antipyretic cont.....
• They do not influence body
temperature when it is elevated by
factors such as exercise, or rise in
ambient temperature.
EX:-Paracetamol (acetaminophen)
Aspirin-prevents the T°-rising effects of
interleukin-1 by preventing the
increase in brain pyrogenic.

30. 3.Antiseptics and Disinfectants
• Antiseptics agent that cause
destruction or inhibition of growth of
microorganism on living surfaces
• Disinfectants agent that cause
destruction or inhibition of growth of
microorganism on non living surfaces
• Spores are not destroyed

31. Actions of Agents
• Cell wall protein is destroyed
• Cell membrane permeability
increases and vital contents leak out
• Metabolism is disrupted
• Cell components become oxidized

32. Classification
1. Phenol derivatives: Phenol, Cresol,
Hexylresorcinol, Chloroxylenol,
Hexachlorophene.
2.Oxidizing agents: Potassiu
permangnate, Hydrogen peroxide,
Benzoyl peroxide.
3.Halogens: Iodine, Iodophores,
Chlorine, Chlorophores

33. Classification cont....
• 4.Biguanide: Chlorhexidine.
• 5.Quaternary ammonium (Cationic):
Cetrimide, Benzalkonium
chloride,Dequalinium chloride.
• 6. Soaps
• 7.Alcohols: Ethanol, Isopropanol.
• 8.Aldehydes: Formaldehyde,
Glutaraldehyde

34. Classification cont......
.
9.Acids: Boric acid, Acetic acid.
10.Metallic salts: Merbromin, Silver
nitrate, Silver sulfadiazine, Mild silver
protein, Zinc sulfate, Calamine, Zinc
oxide.
11.Dyes: Gentian violet, Acriflavine,
Proflavine.
12.Furan derivative: Nitrofurazone.

36. 4. Antibiotics
• Chemical substances that destroy or stop
the growth of microorganisms
• Produced by a microorganism/ semi-
synthetic/ synthetic
• Used in internal or external infection

37. Ideal characteristics of antibiotics
1. Kill or inhibit the growth of pathogens.
2. Cause no damage to the host.
3.Cause no allergic reaction in the host.
4.Stable to store in solid or liquid form.
5.Stay in target tissues for a long time to be
effective.
6.Kill the pathogen before they become resistant
to it.

38. 4. Antibiotics cont....
Antibiotics may be classified according
to their mode of action
1. Inhibition of bacterial cell wall
synthesis
Ex: Penicillin, Cephalosporin

39. 4. Antibiotics cont....
2. Inhibition of protein synthesis
ex: Tetracyclin, Chloramphenicol
3. Inhibition of bacterial cell membrane
function
ex: Nystatin, Amphotericin B
4. Inhibition of nucleic acid metabolism
ex: Actinomycin

40. Another classification of Antibiotics
• Penicillins –Penicillin,, Ampicillin,
Cloxacillin, Amoxicillin.
• Cephalosporins -Cephalexin
• Macrolides -Erythromycin
,Clarithromycin , Azithromycin
• Fluoroquinolones - Ciprofolxacin ,
Levofloxacin, Ofloxacin
• Aminoglycosides-Gentamicin, Amikacin

42. 5. Anthelmintics
• These drugs kill or expel the
helminthes in the GI tract
Ex: Mebendazole
Albendazole
DiEhyl Carbamazine Citrate(DEC)

44. 6. Anesthetics
• Medicines that cause loss of sensation
by reversible CNS depression
Two types
1. General Anesthetics
2. Local Anesthetics

46. 1. General Anesthetics
• Administered by inhalation by gases,
volatile liquids, intravenous route , they
bring about loss of sensation and
consciousness
• EX: Gases- Nitrous oxide, Cyclopropane
• Liquids- Ether, Halothane
• IV- Thiopentone Sodium
• Ketamine

47. 2. Local Anaesthetics

48. • Administered by local infiltration or by
spinal route, which cause loss of
sensation and pain in selected areas
• Here the patient does not become
unconsciousness
Ex: Procaine
Lidocane

49. 2. Local Anaesthetics
• Local anaesthetics are drugs which upon
topical application or local injection
cause reversible loss of sensory
perception, especially of pain, in
restricted area of body
• When it is used on specific nerve
pathway , effect such as analgesia and
paralysis can be achieved

50. Uses of local anaesthetics
1. Surface anaesthesia
2. Infiltration Anaesthesia
3. Nerve Blocks
4. Intravenous Regional Block (Bier’s
Block)
5. Spinal Anaesthesia
6. Epidural Anaesthesia

51. Ex: . Lidocane/Lignocaine,
Bupivacaine

52. • Topical anaesthetic to the skin in the
form of spray, gel, solution

54. 7. Antihistamines
• Compete with histamine in the body
and that are used for treating allergic
reactions
• Ex: Loratadine
Chlorpheniramine
Fexopenadiene
Cetrizine
Promethazine

56. 8. Anticonvulsants (Antiepileptics)
• Anticonvulsants, sometimes also called
antiepileptics, belong to a diverse group
of pharmaceuticals used in prevention of
the occurrence of epileptic seizures.
• The goal of an anticonvulsant is to
suppress the rapid and excessive firing of
neurons that start a seizure.

57. 8. Anticonvulsants (Antiepileptics)
• Anticonvulsant drug decreases the
frequency and/or severity of seizures
in people with epilepsy.
• Ex: Phenobarbital
• Phenytoin
• Valparoate

58. Purgatives / Laxatives

59. 9. Purgatives / Laxatives
• The drug that use to empty the
bowels
• They reduce the viscosity of
content of large bowel
• These drugs facilitate smooth
bowel elimination in those having
defecation problems such as
Constipation/haemorrhoids/Anal
surgery/ Anal fissure

60. 9. Purgatives / Laxatives
1. Bulk Purgatives : Increase volume
of non-absorbable solid residue -ex: Fibergel
2. Osmotic Purgatives : Increase water
content in large intestine.- ex: Lactulose
3. Stimulant Purgatives : Increase
motility and secretion. -ex: Bisacodyl
4. Fecal softeners (lubricants) : Alter
the consistency of feces easier to pass.
ex:Docusate sodium

62. 10. Diuretics
• Diminishing sodium reabsorption at
different sites in the nephron, there
by increasing urinary sodium and
water losses
• The drugs that promotes diuresis
(increased production of urine)

63. Uses
-Hypertension
- Congestive heart failure
- Treatment of oedema
- Renal failure

64. Site of drugs action
• Proximal Convoluted Tubule (PCT)-
Carbonic Anhydrase Inhibitors
ex: Acetazolamide
• Loop of Henle (LH )- Loop diuretics
ex:
• Furosemide
• Bumetanide
• Torsemide

65. Site of drugs action cont...
• Distal convoluted tubule (DC T)-
Thiazide
ex: Hydrochlorthiazide
• Collecting Duct (CD)- Potassium sparing
diuretics
ex: Spironolactone
• All parts of the nephron-Osmotic
diuretics
Ex: Manitol

66. 11. Emetics

67. 11. Emetics
• Emetics are the drugs that induce
vomiting by irritating the stomach and
stimulating the vomiting center in the
brain
• Uses – Accidental overdose of drugs
EX. Lpecac syrup
Apomorphine

69. 12. Antiemetics
• Act on the brain by preventing
stimulation of the vomiting center
Ex:
• Domperidone
• Metoclopramide
• Ondansetron
• Prochlorperazine
• Promethazine

70. 13. Expectorants
• These are the preparations which
decrease the viscosity of mucus and
increase the secretions of respiratory
fluids by direct action on the bronchial
tissues

71. 12. Expectorants cont...
Uses : To treat common colds and
coughs, bronchitis, and all those
situations where there is formation of
tenacious respiratory difficulty
• Eg. Dextromethorphan
• Peritone expectorants

72. 13. Hypnotics

73. 13. Hypnotics
• Hypnotic drug: Chemical substance used
to reduce tension and anxiety and induce
sleep.
• Most such drugs exert a quieting or
calming effect
• Has the potential to produce dependence
Ex. Benzodiazepine
Paraldehyde

74. 14. Myotics

75. 14. Myotics
• Has direct muscarinic action
• Parasympathomimetic(Cholinergic
stimulating)
• These drugs help to decrease
intraocular pressure and increases the
outflow of aqueous humor resulting
constriction of the pupil
Eg. Carbachol
Pilocarpine
Eserine

76. 15. Sedatives
• Sedatives act by increasing the activity of
the brain chemical gamma aminobutyric
acid (GABA)
• This can slow down brain activity in general
• This inhibition of brain activity cause a
person become more relaxed, drowsy and
calm
• Ex: Eszopiclone
• Zolpidem

77. 16.Tranquillisers
• A tranquilizer is a drug that acts on the
central nervous system and is used to
calm, decrease anxiety, or help a person
to sleep.
• These drugs have a calming effect and
eliminate both the physical and
psychological effects of anxiety or fear.
Ex. Chlordiazepoxide
Diazepam

78. N . B : Refer fundamentals of nursing
Unit XIX
Administration of medication to cover
prescriptions, abbreviations, terms
and symbols used in prescription

79. ..
Nurses’ Responsibilities in
Drug Storage

80. Drugs Storage
• Chemical deterioration is hastened by
heat, moisture and in few cases by light
• Sterile substances must be protected
from bacterial contamination
• Therefore storage of drugs is a major
responsibility of a nurse
• When storing drugs the nurse has to
consider following

81. Drugs Storage cont....
• Storage areas should be kept in
clean, cool and dry
• Medicines should bear accurate
labels at all times
• A locked cupboard is necessary
storing medicines.

82. Arrangement of drugs on shelves
• Need adequate shelving for
appropriate storage of the different
categories of drugs
• Shelves should be made of steel or
treated wood.
• Drugs are arranged in alphabetical
order of generic names.

83. Arrangement of drugs on shelves
• Each dosage form of drug is arranged in
separate and distinct areas.
• Sufficient empty space should demarcate
one drug or dosage form from another.

85. Arrangement of drugs on shelves cont...
• Most recently received drugs are
placed behind old stock on the shelf
except where new drugs have
shorter expiration dates.
• Keep the environment clean.
• Always put lids properly on tins
always and at the close of the day.

86. Arrangement of drugs on shelves cont...
• Put drugs in a dry place protected
from light and heat.
• Store liquids on a pallet on the floor
or on the lowest shelf.
• The store must be cleaned daily and
mopped at least once a week.

87. Drug Storage cont.....
• Narcotics and legally restricted
medicines must be kept in a special
locked cupboard
• Key of the cupboard should be with
ward sister / in-charge nurse
• Store the medicines according to
their appropriate temperature

89. Drug Storage cont.....
• Insulin, serum, vaccines and certain
antibiotics should be kept in
refrigerator
• Remove vials from refrigerator before
injection and let it stand for 5- 10
minutes at room temperature.
• Do not heat vials

90. Drug Storage cont.....
• Food should not be stored in the
medicine refrigerator
• Handling of the container should not
spoil the label as original label is
important
• Amber coloured bottles are used to
protect medicines from light

91. Nurses’ responsibilities in drugs
ordering and accounting

92. Ordering and Accounting Drugs
• Sister in charge / in charge nurse
/senior nurse who is delegated for
responsibility regarding drugs ,
orders the drugs to the unit and
accounting them
• Order the drugs according to the
necessity of the patient and unit

93. Ordering and Accounting Drugs cont...
• Should not order the drugs
unnecessarily
• Maintain drugs books separately and
clearly
–Countable drugs book (Tablets/Injections)
–Weekly drugs book (Non- countables)
–Lotion book
–Local purchase drug book
–Dangerous drug book ect..

94. Ordering and Accounting Drugs cont...
• All drugs books need to get register
number from chief pharmacist after
recommended by hospital director or
incharge medical officer
• Every page must be numbered
• Need to maintain content page
• Ex:
• Need separate pages for every drug
Drug Name Page Number
Pethidine 50 mg 25-30

95. Ordering and Accounting Drugs cont...
• Drugs books need to be balanced
daily.
• Time is decided according to ward’s
convenient
• Always ward’s drug balance and
book balance must be equal

96. Drugs ordering
• Before get down new stock needs to
be balanced previous stock
• Then order the drugs according to
need
• According to hospital policy there are
separated dates for get down drugs
from the dispensary

97. Ex: Monday- Lotion
Tuesday- Accountable drugs
Wednesday- Noncountable/weekly
drugs

98. • Some drugs to be got down through local
purchase
Task:
1. Find out what are the local purchase
drugs in your ward
2. Write the steps of local purchasing a
drug
3. Search how often local purchase drugs
to be ordered

99. • Some drugs to be got down for patient’s
BHT
• Such as.....................................
• In here, drug is requested from IDD by
Medical officer in patient’s BHT
• Nursing officer is ordering it in the
relevant drug book
• Then both BHT and relevant drug book to
be sent to the IDD,

100. Ordering and Accounting Drugs cont...
• Maintain separate cleaned and labeled
containers with lids and basket to bring
drugs fro the dispensary
• After drugs received, Receiving nursing
officer must check for correct drug,
amount, expiry date and defaults such
as damages, discolorations

101. Ordering and Accounting Drugs cont...
• If any problem contact with indoor
dispensary
• Receiving nursing officer should
mention amount of drug received
and put signature, designation and
date in the relevant drug book

102. Ordering and Accounting Drugs cont...
• Keep the records regarding out of
stock (OS) & inform other nursing
staff and medical staff
• Ordered drugs which couldn’t use to
the patient return them immediately
to the dispensary