4. DRUGSDRUGS
- are chemical substances that have an
effect on living organisms
THERAPEUTIC DRUGSTHERAPEUTIC DRUGS
- often called MEDICINE, drugs used in
the prevention or treatment of diseases
5. DRUG USES
• SYMPTOMATIC TREATMENT –
Drugs are used to relieve symptoms
• PREVENTIVE DRUGS- helps the
body avoid disease
• DIAGNOSTIC DRUGS – help the
physician determine whether a
disease is present
6. DRUG USES
• CURATIVE DRUGS – eliminate the
disease
• HEALTH MAINTENANCE DRUGS –
help keep the body functioning
normally
• CONTRACEPTIVE DRUGS – prevent
pregnancy
23. PHARMACOKINETIC PHASE
The process of drug movement to
achieve drug action
FOUR BASIC PROCESSES:
Absorption, Distribution, Metabolism
and Elimination
24. PHARMACOKINETIC PHASE
Four Basic Processes:
1. ABSORPTION – movement of drug
particles from the GI tract to the body
fluids
- can be affected by route of
administration or an impairment in
circulation
28. Absorption
HEPATIC 1st
PASS EFFECT –
-some drugs may not go directly to the
systemic circulation after absorption from the
GI tract,
-it 1st passes to the liver via the portal vein;
-some of the drug may become inactive in
the liver thus reducing the amount of active
drug in the systemic circulation
Example: Warfarin (Coumadin)
29. Absorption
• BIOAVAILABILITY- subcategory of
absorption; describes the percentage of
the drug dose that reaches the systemic
circulation
- usually occurs after hepatic 1st
pass in
oral drugs; always less than 100% in PO
drugs and always 100% in IV drugs
- oral drugs with high hepatic 1st
pass
should have double the dose of IV drugs
30. PHARMACOKINETIC PHASE
Four Basic Processes:
2.Distribution – Process by which the
drug becomes available to body
fluids and body tissues
32. PHARMACOKINETIC PHASE
Four Basic Processes:
3. Metabolism – many drugs pass
initially through the liver prior to being
available to tissue.
33. Liver disease may or
action of a drug depending on the
metabolism of the body
Infants and elderly have liver
function
34. PHARMACOKINETIC PHASE
Four Basic Processes:
4. Excretion –
KIDNEYS: primary site of elimination
OTHER ROUTES: hepatic metabolism, bile,
feces, lungs, saliva, sweat and breast milk
35.
36. PHARMACODYNAMIC PHASE
The study of drug concentration and
its effects on the body (primary and
secondary physiologic effects)
• PRIMARY PHYSIOLOGIC
EFFECTS – desirable
• SECONDARY PHYSIOLOGIC
EFFECTS – may be desirable or
undesirable
40. DRUG TOXICITY IN PREGNANCY
AND LACTATION
Drugs taken by the mother can be
passed on transplacentally or via
breastmilk and adversely affect the
unborn or the neonate
49. PARTS OF NEURONS
DENDRITES – conduct impulses to the
cell body and are called AFFERENT (“to”
or “toward”) nerve fibers
AXON – projects and conducts impulses
away from the cell body
- It is called EFFERENT (“away from”)
nerve fiber
52. AUTONOMIC NERVOUS SYSTEM
DIVISIONS:
SYMPATHETIC NERVOUS SYSTEM
PARASYMPATHETIC NERVOUS SYSTEM
-generally function antagonistically
toward each other
- critical to the stability of our internal
environment (homeostasis)
53. SYMPATHETIC NERVOUS SYSTEM
- regulates the expenditure of energy
- Neurotransmitter are known as
CATECHOLAMINES – epinephrine,
norepinephrine, and dopamine
- controls “fight-or-flight responses”
55. PARASYMPATHETIC NERVOUS
SYSTEM
-Works to conserve body energy and
is partly responsible for slowing heart
rate, digesting food, and eliminating
body wastes
- “rest and digest”
-Neurotransmitter: ACETYLCHOLINE
57. CHOLINERGIC FIBERSCHOLINERGIC FIBERS – are
NERVE ENDINGS that liberate
ACETYLCHOLINE
ADRENERGIC FIBERSADRENERGIC FIBERS – are
NERVE ENDINGS that secrete
NOREPINEPHRINE
- They produce opposite responses
61. ANS + DRUG CLASSIFICATION
RULE # 1:
Drugs that mimic the effects of
norepinephrine are called
SYMPATHOMIMETIC drugs (adrenergic
drugs)
Drugs that mimic the effects of acetylcholine
are called PARASYMPATHOMIMETIC
drugs (cholinergic drugs)
62. ANS + DRUG CLASSIFICATION
RULE # 2:
Drugs that block the effects of each
system are called sympatholytics or
parasympatholytics respectively
63. ANS + DRUG CLASSIFICATION
RULE # 3:
adrenergic and cholinergic drugs have
opposite effects
64. ANS + DRUG CLASSIFICATION
RULE # 4:
a drug that mimics the SNS and a drug
that blocks the PNS can cause similar
responses in the same organ
EXAMPLE: Sympathomimetics and
parasympatholytics both increases
heart rate
66. ADRENERGIC AGENTS
(SYMPATHETIC NS)
A.K.A – adrenergics, adrenergic
agonists, sympathomimetics or
adrenomimetics (agonists – promotes;
mimetics – mimics)
- These agents act on one or more
adrenergic receptor sites located on
the cells of smooth muscles
67. ALPHA-ADRENERGIC RECEPTORS –
smooth muscles of the blood vessels
BETA 1 RECEPTORS –
cardiac muscles
1
BETA 2 RECEPTORS –
smooth muscles of the lungs,
uterus, (some in skeletal
muscles)
2
71. EFFECTS:
Stimulation of BETA 2
bronchodilation
Relaxation of the smooth muscles of
the lungs
2
Relaxation of the uterine smooth muscles –
decreased uterine contraction
83. ANTICHOLINERGICS DRUGS
•Drugs that inhibit the actions of
acetylcholine by occupying receptors.
A.K.A. cholinergic/muscarinic
antagonists, anti-spasmodics.
84. Effects of anti-cholinergics
• CVS - inc. HR w/ large doses; dec.
HR in small doses
• GI - relaxes smooth m. tone of
GIT, dec. GI motility &
peristalsis, dec. GI secretions
• GU - relaxes the bladder, & inc.
consriction of internal
sphincter. Urinary retention
results
85. • Ocular - dilates pupils (mydriasis) &
paralyses of ciliary
muscle (cyclopegia) dec. in
accomodation
• Bronchial - dilates the bronchi & dec.
bronchial secretions
• CNS - dec. tremors & rigidity of
muscles. Drowsiness,
disorientation & hallucination
in large doses
Effects of anti-cholinergics
86. Anticholinergic drugs
• Atropine (prototype)
• Scopolamine
• Both drugs act on the muscarinic
receptor but have little effect on the
nicotinic receptors.
87. Uses of atropine
• Preoperative medication to decrease
salivary secretions
• Antispasmodic drug to treat peptic
ulcers
• Increases HR when bradycardia is
present
• Antidote for muscarinic agent
poisoning such as bethanechol
89. RENIN AND SODIUM
RETENTION
- Cells in the kidneys respond to low
blood pressure by releasing an enzyme
called RENIN
RENIN – an enzyme from the kidneys
that activates angiotensin
90. Through a complex series of events,
RENIN causes the kidneys to reabsorb
sodium
Sodium reabsorption, in turn, is always
accompanied by water retention, which
helps to restore blood volume and
blood pressure
91. ANGIOTENSIN AND BLOOD
VESSEL CONSTRICTION
- Renin also activates the blood protein
angiotensinogen to angiotensin
ANGIOTENSIN is a powerful
VASOCONSTRICTOR: it narrows the
diameters of blood vessels, thereby
raising the blood pressure
97. ANGIOTENSIN II RECEPTOR
BLOCKERS (ARBS)
“SARTAN”
ACTION: Blocks the binding of
angiotensin II to the AT 1 receptor
Losartan (Cozaar)
Telmisartan (Micardis)
101. DRUGS administered
by the peripheral route
must be
followed by at least a
20 ml flush of 0.9%
saline and if possible
elevation of the
extremity.
102. TRACHEAL ADMINISTRATION OF
DRUGS
2–3 times the dosage of the drug can be
given via the ET tube, diluted to a volume
of 10–20 ml
- this technique
requires the presence
of an endotracheal or
tracheostomy tube
103. Drugs that can be administered via
TRACHEA:
Adrenaline/Epinephrine
Vasopressin
Atropine
Lignocaine (Lidocaine)
Naloxone
104. Drugs that cannot be administered via
TRACHEA:
Calcium Salts
Sodium Bicarbonate
Amniodarone
107. ATROPINE
blocks the action of acetylcholine at
muscarinic receptors in the parasympathetic
nervous system (PNS). sympathetic nervous
system (SNS)
Parasympathetic stimulation via the vagus
nerve slows the heart. Blocking this in the
sinoatrial (SA) node increases automaticity
and therefore heart rate
108. AMIODARONE
is a complex drug, acting in many ways.
It works by increasing the duration of the
action potential, though it also has
antisympathetic and calcium channel-blocking
properties
109. LIGNOCAINE/LIDOCAINE
is indicated for refractory VF/VT when
the first three defibrillator shocks have
failed to produce are turn of spontaneous
circulation and when amiodarone is
unavailable
It acts by suppressing the excitability of
ventricular cells
110. CHILDREN - SAFETY
OBSERVE, REPORT, TEACH
ABOUT UNDESIRABLE EFFECTS
MEDICATIONS – NO OVER THE
COUNTER WITHOUT CONSULTATION
PREGNANCY/LACTATING ARE
OUT WITH MEDICATIONS
LIVER MUST BE INTACT