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84. The “dominant lethal” test involves the treatment
of a male adult animal with a chemical before
mating; the pregnant female is later examined for
fetal death and abnormalities. The dominant lethal
test therefore is a test of:
A.
Teratogenicity B. Mutagenicity
C. Carcinogenicity D. None of these
85. Pick out the appropriate alimentary route of
administration when passage of drugs through
liver is minimized:
A.
Oral B. Transdermal
C. Rectal D. Intraduodenal
86. Biotransformation:
A. Renders the drug more lipid soluble
B. Can be altered by drugs
C. Is necessary for all drugs for their elimination
D. Takes place only in the liver
87. Which one is an example of parenteral route?
A. Rectal B. Oral
C. Sublingual D. Inhalation
88. Alcohol absorption is fast from intestine due to:
A. Its lipid solubility and non-electrolyte nature
B. Its lipid solubility and highly ionized nature
C. Its absorption by active transport method
D. None of the above
89. Phenylephrine causes:
A. Constriction of vessels in the nasal mucosa
B. Increased gastric secretion and motility
C. Miosis
D. All of the above
90. Choose one correct statement about characteristics
of a particular route of drug administration:
A.
Intravenous route of drug administration
provides a rapid response
B. Intramuscular route of drug administration
requires a sterile method
C. Inhalation route of drug administration
provides slow access to the general blood
circulation
D. Subcutaneous route of drug administration may
cause local irritation reaction
91. Which of the following is a type II (unpredictable)
adverse drug reaction?
A.
Side effect B. Toxic effect
C. Idiosyncrasy D. Physical dependence
92. Why some drugs show complicated penetration
through brain–blood barrier?
A.
Due to high lipid solubility
B. Due to meningitis diseases
C. Due to absence of pores in the brain capillary
endothelium
D. All of the above
93. Receptors perform the following function:
A. Ligand recognition
B. Signal transduction
C. Disposal of agonists and antagonists
D. Both A and B
94. The volume of distribution (Vd) can be related to:
A.
Daily dose of an administrated drug
B. An administrated dose to a body weight
C. An uncharged drug reaching in blood circulation
D. The amount of a drug in the body to the
concentration of a drug in plasma
95. A receptor which itself has enzymatic property is:
A. Insulin receptor B. Progesterone receptor
C. Thyroxine receptor D. Glucagon receptor
96. The movement of drug substance from a region of
high concentration to a region of low concentration
is known as:
A.
Active transport B. Bioavailability
C. Simple diffusion D. Pinocytosis
97. Drug metabolism can be enhanced by the
following factors, except:
A.
Smoking
B. Acute alcohol ingestion
C. Exposure to insecticides
D. Consumption of charcoal boiled meat
98. Half-life (t½) is the time needed to:
A. Change the amount (50%) of a drug substance
in plasma during elimination
B. Metabolize a 75% of an introduced drug into
the active metabolite
C. Attach 50% of drug to plasma proteins
D. All of the above
99. The most important factor governing absorption
of a drug from intact skin is:
A.
Molecular weight of the drug
B. Site of application
C. Lipid solubility of the drug
D. Nature of the base used in the formulation
100. Biotransformation of the drugs is to render them:
A. Less ionized
B. More pharmacologically active
C. More lipid soluble
D. Less lipid soluble
101. Hippocrates is known as
A. Father of Medicine
B. Father of Pharmacognosy
C. Father of Polypharmacy
D. Father of Experimental Medicine
102. The types of antagonism are:
A. Summarized B. Potentiated
C. Additive D. Competitive
103. Metabolism phase 1 is:
A. The process of acetylation and methylation
B. The process of transformation of substances by
various reaction like oxidation, reduction or
hydrolysis
C. Glucuronide formation
D. Attachment to plasma proteins
Section 1 Pharmacology
9
104. Intramuscular route:
A. provides faster absorption as compared to oral
route
B. Can be used to inject mild irritant type substance
C. In case of child is made into the gluteus
maximus muscle
D. Can be used to inject a volume of 25 ml
105. A process is called _________ in which a weak acid
becomes less water-soluble and more lipid-soluble
at low pH.
A.
Distribution B. Permeation
C. Protonation D. Elimination
106. In case of liver disorders accompanied by a decline
in microsomal enzyme activity the duration of
action of some drugs is:
A.
Decreased
B. Enlarged
C. Remained unchanged
D. Changed insignificantly
107. Majority of drugs which are capable to cross
plasma membrane are:
A.
Weakly basic drugs
B. Weakly acidic drugs
C. Strong electrolytes
D. Nonpolar drugs
108. Two drugs binding to the same receptors is:
A. Chemical antagonism
B. Pharmacokinetic antagonism
C. Competitive antagonism
D. Non-competitive antagonism
109. Elimination is best described by:
A. Rate of renal tubular reabsorption
B. Clearance speed of some volume of blood from
substance
C. Time required to decrease the amount of drug
in plasma by one-half
D. Clearance of an organism from a xenobiotic
110. The duration of action of a drug is dependent of its:
A. Plasma and tissue binding
B. Metabolism
C. Tubular filtration and secretion
D. All of the above
111. Pharmacodynamics involves the study of
following, except:
A.
Therapeutic effects of drugs
B. Absorption and distribution of drugs
C. Mechanisms of drug action
D. Biological effects of drugs
112. Most drugs and metabolites are excreted by:
Section 1 Pharmacology
10
A. The kidneys
B. The bile
C. The lungs
D. Perspiration, saliva and tears
113. Once the drug enters the blood, which it
subsequently penetrates the tissues and other
body uids depends on:
A.
Capillary permeability
B. Extent of plasma protein and tissue binding
C. Transport mechanism
D. All of the above
114. Which one is the correct statement about most of
the drug receptors?
A.
They are small molecules having molecular
weight range between 100 and 1000
B. They are lipids in nature arranged in a bilayer
configuration
C. They are proteins in nature located on cell
membranes, cytosol or on nuclear membrane
D. DNA molecules
115. Drugs interact with their receptor sites by forming:
A. Ionic bonds
B. Hydrogen bonds
C. van der Waals bond
D. All of the above
116. If an agonist can produce submaximal effects and
has moderate efcacy it is called:
A.
Partial agonist B. Antagonist
C. Agonist-antagonist D. Full agonist
117. The substance binding to one receptor subtype
as an agonist and to another as an antagonist is
called:
A.
Competitive antagonist
B. Irreversible antagonist
C. Agonist-antagonist
D. Partial agonist
118. When therapeutic effects decline both below and
above a narrow range of doses, a drug is said to
exhibit:
A.
Ceiling effect
B. Desensitization
C. Therapeutic window phenomenon
D. Non-receptor-mediated action
119. Choose the substance which changes the activity
of an effectors element but does not belong to
second messengers:
A.
cAMP B. cGMP
C. G-protein D. Calcium ions
120. Characteristic unwanted reaction which is not
related to a dose or to a pharmacodynamic
property of a drug is called:
A.
Idiosyncrasy B. Hypersensitivity
C. Tolerance D. Teratogenic action
121. What term is used to describe a more gradual
decrease in responsiveness to a drug, taking days
or weeks to develop?
A.
Refractoriness B. Cumulative effect
C. Tolerance D. Tachyphylaxis
122. Tolerance and drug resistance can be a resultant
as a consequence of:
A.
Drug dependence
B. Increased metabolic degradation
C. Depressed renal drug excretion
D. Activation of a drug after hepatic first-pass
123. The route of drug administration that gives the
most rapid onset of the pharmacological effect is:
A.
Intramuscular injection
B. Intravenous injection
C. Intradermal injection
D. Peroral administration
124. What is the type of drug-to-drug interaction
which is connected with processes of absorption,
biotransformation, distribution and excretion?
A.
Pharmacodynamic interaction
B. Physical and chemical interaction
C. Pharmaceutical interaction
D. Pharmacokinetic interaction
125. The removal of oxygen or an alteration in a drug
which leads to a decrease in the proportion of
oxygen in the drug compound is known as:
A.
Oxidation B. Reduction
C. Hydrolysis D. All the above
126. The absorption time of a drug can be reduced by:
A. Making a more soluble salt — for oral
B. By using hyaluronidase — for injection
C. By using vasoconstrictor substances
D. By giving combination of drugs
127. Denition for a therapeutic dose is:
A. The amount of a substance to produce the
minimal biological effect
B. The amount of a substance to produce side
effects for an organism
C. The amount of a substance to produce the
required effect in most patients
D. All of the above
128. If two drugs with the same effect, taken together,
produce an effect that is equal in magnitude to the
sum of the effects of the drugs given individually,
it is called:
A.
Antagonism
B. Potentiation
C. Additive effect
D. None of these
129. Choose the best suitable statement regarding
clinical trials of a new drug:
A.
Phase I involves the study of a small number
of normal volunteers by highly trained clinical
pharmacologists
B. Phase II involves the use of the new drug in
many patients (100–5000) who have the disease
to be treated
C. Phase III involves the determination of the
drug’s therapeutic index by the cautious
induction of toxicity
D. Chemical antagonist
130. Parenteral administration:
A. Cannot be used with unconsciousness of
patients
B. Generally, results in a less accurate dosage than
oral administration
C. Usually produces a more rapid response than
oral administration
D. Is too slow for emergency
ANSWER KEY
1. C 2. A 3. B 4. D 5. C 6. D 7. A 8. B 9. B 10. A 11. A 12. C 13. C 14. B
15. A 16. C 17. D 18. A 19. B 20. B 21. B 22. B 23. C 24. A 25. C 26. C 27. A 28. C
29. A 30. A 31. A 32. B 33. D 34. C 35. A 36. D 37. B 38. D 39. C 40. B 41. C 42. A
43. C 44. B 45. B 46. B 47. C 48. C 49. A 50. B 51. D 52. D 53. A 54. B 55. C 56. C
57. A 58. B 59. D 60. C 61. C 62. B 63. A 64. C 65. C 66. A 67. C 68. C 69. D 70. D
71. C 72. B 73. B 74. D 75. D 76. A 77. D 78. B 79. B 80. A 81. C 82. D 83. D 84. B
85. C 86. B 87. D 88. A 89. A 90. C 91. C 92. C 93. D 94. D 95. A 96. C 97. B 98. A
99. C 100. D 101. A 102. D 103. B 104. B 105. C 106. B 107. A 108. C 109. D 110. D 111. B 112. A
113. D 114. C 115. D 116. A 117. C 118. C 119. C 120. B 121. C 122. B 123. B 124. D 125. B 126. A
127. C 128. C 129. A 130. C
Section 1 Pharmacology
11
2. Pharmacology of Peripheral Nervous System
Our body function is regulated and integrated by the two
systems: (1) The endocrine and (2) the nervous system.
The endocrine system sends signals to target tissues by
varying the levels of blood-borne hormones.
The nervous system, more than 10 million neurons
communicate with other through chemical mediators
between the adjacent neurons and also exert their effects
on peripheral structures by release of neurotransmitters.
The pharmacology of nervous system can be discussed
as follows:
NEURO AND PSYCHOPHARMACOLOGY DIFFERENCES
i. Neuropharmacology (the peripheral autonomic
nervous system)
z
It deals with drugs that produce their primary
therapeutic effects by mimicking or affecting the
response of the autonomic nervous system are called
autonomic drugs.
ii. Psychopharmacology (the CNS)
z
It deals with those drugs that affect the central
nervous system (CNS) act by altering some step in
the neurotransmission process.
z
“Drugs affecting the CNS” may act presynaptically
by influencing the production, storage, release and
termination of action of neurotransmitters (NTs).
All these NTs combine with their receptors and
regulates the physiological functions, but any form of
deficiency or excess can cause many diseases mentioned
in Table 2.2.
Synapse and Ganglia
Synapse is the junctional region between two neurons
where one neuron relays the impulse to other so that the
impulse is transmitted.
Ganglion: It is the site where the axons of the
preganglionic fibers make synapse with the neurons of
the postganglionic fibers.
Cholinergic and adrenergic fibers
Cholinergic fibers are those which release acetylcholine
on stimulation.
They are:
z
All preganglionic fiber (both sympathetic and
parasympathetic)
z
Postganglionic parasympathetic fiber
Table 2.1: Difference between CNS and ANS
Parameters Differences
Circuitry CNS is much more complex than that of the autonomic nervous system
Synapses The number of synapses in the CNS is greater
inhibitory neurons Powerful networks of inhibitory neurons that are constantly active in modulating the rate of
neuronal transmission is prominently found in the CNS
Number of communicating
neurotransmitters
The CNS communicates through the use of more than 10 (and perhaps as many as fty)
different neurotransmitters
The autonomic nervous system uses only two primary neurotransmitters, e.g. acetylcholine
and noradrenaline
Table 2.2: Deciency and excess of NT and its associated disease
NTs Disease
Overactivity of DA in the mesolimbic Schizophrenia
Either cholinergic overactivity or dopaminergic deciency Parkinsonism
Deciency of serotonin and/or noradrenaline Depression
NMDA-mediated overactivity or GABA underactivity Epilepsy
Signicant loss of cholinergic neurons in the temporal lobe Alzheimer’s disease
Table 2.3: Differences between sympathetic and parasympathetic system
Particulars Sympathetic system Parasympathetic system
Purpose Tackling stress and emergency Assimilation of food and conservation of energy
Origin Thoracolumbar Craniosacral
Distribution T
Related transmitter NA (major), Ach (minor) ACh
Section 1 Pharmacology
Stablility of transmitter NA stable, diffuses at wider action ACh rapidly destroyed locally by cholinesterase
12
1–L3
III, IV, IX, X (S2–S4)
Fig. 2.1: Structural layout of nervous system
Postganglionic sympathetic fibers supplying sweat gland
and piloerector muscle
z
Nerve supplying to adrenal medulla
z
Skeletal neuromuscular junction
z
Some CNS neurons.
Adrenergic fibers are those which release noradrenaline
on stimulation. They are
All postganglionic sympathetic fibers accept those
supplying to sweat glands.
Sympathetic and parasympathetic target cells
Sympathetic system
z
Vascular smooth muscles
z
Visceral smooth muscles
z
Cardiac muscles (both atria and ventricles)
z
Dilator pupillae of the eye.
Parasympathetic system
Exocrine gland
Smooth muscles of viscera
Atrial muscles (not ventricular)
Constrictor pupillae of the eye.
Neurotransmission
Neurotransmission in cholinergic neurons involves six
steps.
The first four—synthesis, storage, release and binding of
the acetylcholine—to a receptor, are followed by the fifth
step, in the last step the recycling of choline occurs. In
this step, neurotransmetters get degraded in the synaptic
gap (space found between the ending of neurons and
adjacent receptors found on nerves or an effector organ)
Adrenergic transmission
Adrenergic neurons closely resemble to cholinergic
neurons, except that norepinephrine is the
neurotransmitter instead of acetylcholine.
Neurotransmission takes place at neurons bead-like
enlargements called varicosities.
The process involves five steps: The synthesis, storage,
release and receptor binding of the norepinephrine,
followed by the neurotransmitter from the synaptic
gap.
Adrenergic receptors
In the ANS, adrenergic neurons release NA which binds
with adrenergic receptors and propagate the nerve
impulses.
The two main types of adrenergic receptors are
a-receptors and β-receptors. These receptors further
sub-classified as
a1 and β1 mostly produce excitation, and a2 and 2 mostly
a— a1, a2 and β1, β2, β3.
produce inhibition.
Cholinergic receptors
In ANS, cholinergic neurons release ACh a
neurotransmitter. All sympathetic and parasympathetic
neurons are cholinergic and also all parasympathetic
postganglionic neurons are cholinergic.
Nicotinic receptors are preset on the dendrites or the cell
bodies of postganglionic neurons of both sympathetic
and parasympathetic neurons.
Muscarinic receptors are present on the all visceral
organs. The muscarine obtained from mushroom, mimics
the action of ACh on these receptors.
There are two types of cholinergic receptors: Muscarinic
and nicotinic.
Nicotinic receptors
The nicotine is never observed into normal (nonsmoker)
person still the receptors known as nicotinic, this is
because this type of receptors are known as nicotinic,
because these types of receptors stimulated by nicotine
Section 1 Pharmacology
13
Table 2.4: Adrenergic recetors and its location
Receptor Location
Adrenergic receptors
a1 Postjunctional on effector organs like radial and sphincter muscles of iris (eye), heart, some BV (blood vessels), bronchial
glands (lungs), liver, gut, skin, sex organs, etc.
a2 Prejunctional at the nerve ending. On the brain, pancreatic β cells, fat cells, gut muscles, veins, etc.
β1 Located at heart, salivary glands, juxtaglomerular apparatus of kidney and posterior pituitary.
β2 Lungs, BV, uterus, liver, eye, gut, urinary bladder, spleen, skeletal muscle, certain veins, etc.
β3 Brown adipose tissue, where there function is to generate the heat by thermogenesis.
which mimics the action of ACh but having more affinity
than ACh.
NM: They are present on the neuromuscular junction
mainly on the skeletal muscles. They cause depolarization
at the muscle end plate which leads to contraction of
muscle.
NN: These are present on autonomic ganglia, adrenal
medulla and CNS. At autonomic ganglia it causes
depolarization of postsynaptic neurons and propogate
impulses through it.
Muscarinic receptors
The substance known as muscarine from mushroom
(Amatina muscaria) is activating these type of receptors,
so named as muscarinic receptors. They are G-protein
coupled receptors (GPCRs). When ACh binds with them,
they activated by Gi, containing 7-helical segments of
amino acids where the amino end of chain is extracellular
and carboxyl end of chain is intracellular and inhibits action
of AC. By molecular cloning they are subdivided into M1,
M2, M3, M4, and M5.
M1: It is present on the autonomic ganglia, on the
gastric gland and at the certain parts of the brain like
hippocampus from limbic system and at the corpous
straitum. It has role in gastric secretion and histamine
release. It acts through Gq protein and activates
phospholipase C (PLc) which generate DAG and IP3 as
2 messenger. Sometimes they also activate PL-A2.
M2: They act through Gi protein which inhibits all the
functional activities. Located on the heart (SA node, AV
node, atria, ventricle), on the cholinergic nerve ending
and visceral smooth muscle. They inhibit AC resulting
in hyperpolarisation of the neurons and decrease activity
of SA node and conduction through AV node leads to
bradycardia.
M3: It is located on the visceral smooth muscle, iris,
ciliary muscle and exocrine glands. They are also GPCRs
acts by Gq protein. Their activity is dominated in smooth
muscle than M2.
M4: Not abundant in body. They transmit neurotransmitter
in certain areas of brain and acts through Gi protein.
M5: It acts by Gq protein. Derifinacin is selective
antagonist and related to dopamine release.
Neurotransmitters
Neurotransmitters are chemical substances which transmit
impulses from one neuron to another neuron or from
neuron to effector organ and this process is known as
neurotransmission.
Table 2.5: Difference between a- and β-receptors
Receptors Rank order of potency of
Antagonist Effectors pathway Autoreceptor activity
agonist
a-receptor Ad a1 + a2
a1 + a2
NA
a1-Prazosin
a1-Yohimbine
IP
/DAG/cAMP Dominant
3
ISO-no a action
β-receptor Ad β
+ β2, weak β3 activity NA
1
β1+ β2 but no β2 activity
ISO-β1 + β
2
Table 2.6: Difference between β1- and β
β1-Atenolol selective
β2-Butoxamine selective
Propranolol (nonselective)
-receptors
2
cAMP Ca
2+
Receptors Location Selective agonist Selective antagonist Potency of NA as
agonist
β
–receptor Heart and kidney Dobutamine Atenolol Strong Moderate
1
β
–receptor Bronchial tree, blood
2
vessels, uterus, GI
Section 1 Pharmacology
14
and urinary tract
Terbutaline a1–methyl
propanolol
No action Present
Less
Potency of ISO as
agonist
Table 2.7: Difference between a1-and a
-receptors
2
Receptors Location Function Selective agonist Selective antagonist Effector pathway
a1-receptor Postjunctional /
effector organ
Smooth muscle
contraction
Phenylephrine Prazosin IP3/DAG
Gland secretion
Gut relaxation
a2-receptor Prejunctional or
nerve ending
Inhibition of
transmitter release
Clonidine Yohimbine CAMP
Vasoconstriction
Decreased central
sympathetic ow
Types
Table 2.8: Gross effects of ANS stimulation at organ level
Organ Sympathetic
stimulation
Parasympathetic
stimulation
1. Heart
• Rate
• Force
• Conduction velocity
• Cardiac output
2. Blood Vessels • Constriction of arterioles and veins rise in
• + ve chronotrophic effect
• + ve ionotrophic effect
• Increased
• Increased
• BP (
a1 + a2 activation)
• Dilation of arterioles and veins and then fall
• – chronotrophic effect
• – ve ionotrophic effect
• Decreased
• Decreased
• No effect on arterioles, except erectile tissue
• Vasodilatation and then erection
vasodilatation
in BP (β2 action)
3. Bronchial Tree
• Smooth muscles
• Glands
• Relaxation (bronchodilatation)
• ± or decreased or increased secretion
• Constriction
• Relaxation
• Increased secretion
4. Gi Tract
• General smooth muscle
• Sphincters
• Exocrine glands
• Relaxation
• Contraction
• Contraction
• Relaxation
• Increased secretion
5. Eye Pupillary dilatation Pupillary constriction
6. Kidney Increased renin production, decreased renal
±
vasoconstriction
7. Uterus Usually contraction in
Unpredictable
pregnancy and relaxation
in nonpregnant uterus
8. Urinary Bladder Sphincter contraction and detrusor relaxation Evacuation of bladder
9. Male Sex Organ Contraction of the vas and ejaculation Erection of penis
10. Liver Glycogenolysis ±
11. Skin
• Hair
• Sweat glands
• Piloerection
• Sweating
±
±Effect
Section 1 Pharmacology
15
Fig 2.2: Classication of cholinergics
Cholinergics are (cholinomimetic, parasympathomimetics)
drugs which produce actions similar to that of ACh, either
by directly interacting with cholinergic receptors or by
increasing availability of ACh at these sites.
Direct-acting Drugs: Acetylcholine
Direct-acting drugs. These are called ‘cholinergic
agonists’. They (direct-acting drugs) combine with AChR
(acetylcholine receptor) and act as agonists of AChR.
Indirect-acting drugs. These drugs inhibit the
cholinesterase enzyme and thus increases the stay of
ACh in the local region.
Reversible binding drugs. Cholinomimetic drugs bind
with enzyme cholinesterase by weak bonds (H-bond,
van der Waals bonds). The bond may be broken down.
Irreversible binding drugs. Cholinomimetic drugs bind
with enzyme cholinesterase by strong bonds (covalent
bond). The bonds may not be broken down.
Anticholinesterase poisoning
They are easily available and extensively used as
insecticides; accidental as well as suicidal and homicidal
poisoning are common. Local muscarinic manifestations at
the site of exposure (skin, eye, GIT) occur immediately and
are followed by complex systemic effects due to muscarinic,
nicotinic and central actions. There are:
1. Irritation of eye
2. Lacrimation
3. Salivation
4. Sweating
5. Copious tracheobronchial secretion
6. Miosis
7. Blurring of vision
8. Breathlessness
9. Colic
10. Involuntary defecation and urination
11. Fall in BP
12. Tachycardia
13. Cardiac arrhythmias
Section 1 Pharmacology
14. Vascular collapse
15. Muscular fasciculations
16
16. Weakness
17. Respiratory paralysis
18. Excitement
19. Ataxia
20. Convulsions
21. Coma and death.
Anticholinergic drugs
Conventionally, anticholinergic drugs are those which
block actions of ACh on autonomic effectors and in the
CNS exerted through muscarinic receptors. Though
nicotinic antagonists also block certain actions of ACh,
they are generally referred to as ganglion blockers and
neuromuscular blockers.
Atropine, the prototype drug of this class, is highly
selective for muscarinic receptors. All anticholinergics are
competitive antagonists.
Drugs acting on peripheral nervous system:
These are divided into two parts:
1) Peripherally-acting.
2) Centrally-acting.
Peripherally-acting drugs:
1) Neuromuscular blocking agent or nondepolarizing
competitive blocker divided into three parts:
z
Long-acting—D-tubocurarine, pancoronium
z
Intermediate—Atracurium
z
Short-acting—Mivacurium
2) Directly-acting—Dantrolene sodium, quinine
A) Mechanism of action
Competitive blockers have affinity for nicotinic
cholinergic receptor at muscle and plate
It is a protein with 5 subunits (a, d, β, ¥, £) which are
arranged in rosette surrounding sodium.
The two alpha-receptors carry 2 acetylcholine binding
sites, they both are negatively charged groups which
combine with cationic head of acetylcholine—opening
of sodium channel.
Most of competitive
Blockers have sodium atom which provides the attraction
of same site.
Fig 2.3: Classication of anticholingeric drugs
Uses:
Short-term purpose
Adjacent to general anaesthesia
Convulsion and trauma and electroconvulsive therapy
Severe case of tetanus and stratus epilepticus
Small dose of D-tubocurarine produce weakness in
patient of myaesthenia gravis
B) Mechanism of action
It decreases depolarization-triggered release of calcium
from sarcoplasmic reticulum
Orally used—decrease spasticity in upper motor neurone
(UMN) disorder, hemiplegia, paraplegia, cerebral palsy.
Uses
It is the drug of choice for malignant hyperthermia.
Centrally-acting drugs:
Mephenesin
Chlorzoxanone
Diazepam
Beclofen
1) They decrease skeletal muscle tone by selective action
on cerebrospinal axis without altering consciousness
decrease muscle tone without voluntary power
2) They decrease spinal and supraspinal reflex involved
in regulation of muscle tone
3) They have some sedative properties.
4) No effect on neuromuscular transmission but
decrease rigidity—UPN spasticity and hyperflexia.
Uses
Spastic neurological disorder
Tetanus
Torticollis
Electroconvulsive therapy
Acute muscle spasm
Anxiety and tension
Lumbago
Back ache
Orthopaedic manipulation
Adrenergic system / Sympathomimetics
Consist of adrenalin, noradrenalin, phenylephrine,
salbutamol, tyramine, ephedrine and amphetamine.
Classification (mnemonic):
2
UP BANAV
C
Cardiac stimulant: Adrenaline, epinephrine
CNS stimulant: Amphetamine
Uterine relaxant: Isoxsufrine, Salbutamol, terbutaline
Pressure agent: Ephedrine, dopamine
Bronchodilators: Salbutamol, terbutaline
Anorectic: Fanfluramine, dexfenfluramine
Nasal decongestant: Oxymetazoline, xylometazoline
Vasodilators: Isoxsufrine
Side effects
Hyperglycaemia
Hypercalcemia
Section 1 Pharmacology
17
Hypokalaemia
Angina MI stroke.
Pharmacological action (mnemonic):
3
Hariyada ka CM B
Heart rate increases
CNS (poor penetration in brain)
Metabolic—glycogenolysis so that hyperglycaemia
me GRE dega
resulted hypoglycaemia and increases free fatty acid.
Blood vessels—cause vasoconstriction, and vasodilation
Blood pressure increase
Bladder—decrease micturition
GIT—peristalsis decreases
Respiration—bronchodilation
Eye—mydriatic
Uses (Mnemonic):
2
UV me BAM
NIC
Nocturnal enuresis in children
Insulin hypoglycaemia
Cardiac uses—cardiac arrest which may be partial or
complete AV block
Central uses—obesity
Uterine relaxant
Vascular uses—control of local bleeding along with local
anaesthesia
Bronchial asthma
Allergic disorder—anaphylactic shock
Mydriatic
Antiadrenergic system: Also called sympatholytic
including alpha-blocker and beta-blocker adrenergic
system. These increase the activity of nervous system.
These are the drugs which antagonise the receptor action
of adrenaline and related drugs
They are competitive antagonist at alpha or beta or both
types of adrenergic receptors.
Alpha-blockers: These drugs inhibit adrenergic response
mediated through the alpha-adrenergic receptor without
affecting those mediated through a beta-blocker.
Classification:
1) Nonequilibrium type: Phenoxybenzamine
2) Equilibrium type: Competitive
A) a nonselective
B) a 1 selective
C) a 2 selective.
A. Nonselective—ergotamine, dihydroergotamine,
phentolamine.
Features:
z
Postural Hypotension
z
Empotence
Section 1 Pharmacology
z
Nasa-blockade
B. a 1 selective—prozosin, terazosin, doxazosin.
18
C. a 2 selective—yohimbine.
Pharmacological action
Decrease in blood pressure and tachycardia
Nasal stuffiness and meiosis
Intestinal motility increases
Hypotension—decrease in renal blood flow, decrease in
GFR membrane resorption of sodium ion water result
in water retention
Inhibit ejaculation.
Side effects
Postural hypotension
Nasal blockage
Loose motions
Fruit retentions
Inhibition of ejaculation.
Uses
1. Migraine: Severe headache with vomiting, sudden onset
of severe headache (pain in light and sound)
2. Secondary shock: Shock due to blood or fluid loss is
accompanied by reflex vasoconstriction
3. CHF—4D drugs are used.
z
Digoxin
z
Digitalis
z
Diuretic
z
Dilators
-Heart size increases due to lung conditions are called
cor pulmonale.
4. Benign hypertrophy due to lung condition of prostate
5. Peripheral vascular disease—used when vasoconstriction
is prominent.
6. Pheochromocytoma—it is a tumour of adrenal gland
due to excess catecholamine blood volume.
7. Hypertension phentolamine/phenoxybenzamine—
Useful in controlling blood pressure during clonidine
withdrawal and cheese reaction in patient on MAO
inhibitors.
Anticholinergic system or parasympathetic or antimuscarinic system
Drugs block muscarinic receptor.
Nicotinic antagonistics are referred as ganglionic
blockers or neuromuscular blocker.
Classification
1.
Natural alkaloid: Atropine, hyoscine (scopolamine)
2. Semi-synthetic: Homatropine, atropine, hyoscine, butyl
bromide, ipratropium bromide
3. Synthetic
z
Mydriatic: Tropicamide
z
Antisecretory: Antispasmodic—propantheline,
glycopyrralate, diclomine, pirenzepin
z
Antiparkinsonism: Benzhexol, biperidine, benztropin.
Action: Atropine
1) Central nervous system
Stimulant action but not appreciable at low dose of
restricted entry into the brain (hyoscine produce it at
low dose).
It stimulates vagal respiratory, vasomotor center.
Has antimotion sickness property, site of action not clear.
By blocking anticholinergic overactivity in basal ganglia.
It suppresses trimmer and rigidity in parkinsonism.