Upload
isaac-amankwaa
View
243
Download
1
Embed Size (px)
Citation preview
8/11/2019 Pharmacology lecture notes
1/162
Pharmacology and
Therapeutics
Lecturer:Isaac Amankwaa
8/11/2019 Pharmacology lecture notes
2/162
COURSE OBJECTIVES
By the end of the course the student will:
Discuss the various sources of drugs
Explain the principles of pharmacology: pharmacokinetics and
pharmacodynamics
Explain the indications, dosages, actions, side effects,
contraindications, drug interactions and nursing implications of
drugs on the various systems of the body
Identify the nursing responsibilities in administering the various
drugs
Apply current drug policies in the country.
8/11/2019 Pharmacology lecture notes
3/162
COURSE CONTENT
1. Sources of drugs
2. General drug metabolism
3. Analgesics4. Anaesthesics
5. Tranquilizers: major and minor
6. Antidepressants7. Anticholinergics
8/11/2019 Pharmacology lecture notes
4/162
Course content CTD
8. Drugs acting on the cardio-vascular system
9. Haematinics
10.Drugs acting on the respiratory system11.Drugs acting on the digestive system
12.Drugs acting on the urinary system
13.Drugs used in infections14.Miscellaneous drugs
8/11/2019 Pharmacology lecture notes
5/162
Course content CTD
Antimetabolites
Eye preparations
Ear preparations Drugs acting on the endocrine system
8/11/2019 Pharmacology lecture notes
6/162
TERMINOLOGIES
8/11/2019 Pharmacology lecture notes
7/162
Application of Pharm to Nursing
Class to be divided into 4 groups to discuss1. Role of the nurse in drug therapy
2. Drug administration practices students
observed (good & bad) during their lastclinical placement
3. Why you think nurses must learn pharm in
nursing.4. The nurse, pharmacist and doctor who plays a
central role in drug therapy and why?
8/11/2019 Pharmacology lecture notes
8/162
TERMINOLOGIES
8/11/2019 Pharmacology lecture notes
9/162
PHARMACOLOGY
The study of the interaction ofsubstances(drugs), other than foods, with
living systems
or
It is the study of effect of drugs on living
organisms.
8/11/2019 Pharmacology lecture notes
10/162
THERAPEUTICS
The use of drug to diagnose,
prevent or treat diseases or to
prevent pregnancy
8/11/2019 Pharmacology lecture notes
11/162
Clinical Pharmacology
The study of drugs in humans-
includes the study of drugs in
patients as well as healthyvolunteers
8/11/2019 Pharmacology lecture notes
12/162
A drug/Medication:
A chemical used in the diagnosis,
treatment, or prevention of disease.
They are used interchangeably.
8/11/2019 Pharmacology lecture notes
13/162
Sources of drugs
Two main sources:1. Natural
2. Synthetic
8/11/2019 Pharmacology lecture notes
14/162
8/11/2019 Pharmacology lecture notes
15/162
Synthetic Sources
Prepared by chemical reactions in thelaboratory.
Majority of drugs prepared by this
method.
One such area is Biotechnology:
manipulation of proteins to permit the large-
scale industrial production of complex
natural substances (e.g. hormones).
8/11/2019 Pharmacology lecture notes
16/162
Drug names
A drug may have about four names:.
1. Chemical name
2. Generic name (nonproprietary)
3. Official name
4. Trade name
8/11/2019 Pharmacology lecture notes
17/162
Types of drug names Examples
Chemical name N-Acetyl-para-aminophenol
Generic name acetaminophen
Trade names Paracetamol, Tylenol, EFPAC
8/11/2019 Pharmacology lecture notes
18/162
Which name to use? Generic or trade?
Disadvantages of using generic names
They are long and complicated
They are difficult to remember
Disadvantages of trade names:
unlimited trade names which create confusion.
Can result in double medication
8/11/2019 Pharmacology lecture notes
19/162
Controlled substances
Can cause physical or psychologicaldependence or both.
Its use is subject to considerablecontrol.
The nurse has both legal and ethical
responsibilities when administeringthese drugs.
8/11/2019 Pharmacology lecture notes
20/162
Nonprescription or Over-the-counter
drugs (OTCs)
These are drugs that can be purchased
without prescription.
Considered relatively safe for the layperson to
use when taken according to directions
provided by the manufacturer
8/11/2019 Pharmacology lecture notes
21/162
Medication orders
Patient medications must have an order from
the physician, nurse practitioner or medical
assistant.
Medication orders are written in the form of
PRECRIPTION
8/11/2019 Pharmacology lecture notes
22/162
Types of Medication orders
1. A standing order: carried out as specified until it iscancelled by another order. E.g. Caps amoxicillin 500mgtds for 7 days
2. As needed (p.r.n.) order3. Single order
Directive is carried out only once at the timespecified by the physician.eg atropine given to
preoperative patients4. Stat order
Also a single order
Carried out at once
8/11/2019 Pharmacology lecture notes
23/162
Science
of Pharma-cology
Pharmacognosy
Pharmacokinetics
Pharmacodynamics
PharmacotherapeuticsToxicology
8/11/2019 Pharmacology lecture notes
24/162
EFFECTS OF DRUGS
Drugs are given for two effects:
Local effects
Systemic effect
Both can further be grouped into
desirable and
Undesirable effects
8/11/2019 Pharmacology lecture notes
25/162
PRINCIPLES OF PHARMACOLOGY
Chapter Two
25
8/11/2019 Pharmacology lecture notes
26/162
1. Pharmacokinetics
2. Pharmacodynamics
8/11/2019 Pharmacology lecture notes
27/162
Pharmacokinetics
Processes that affect a drug from the time it
enters the body until it leaves the body
It answers the question: how does the body
handles medications.
8/11/2019 Pharmacology lecture notes
28/162
Components of PK.
Absorption (A)
Distribution (D)
Metabolism (M)
Excretion (E)
ADME
8/11/2019 Pharmacology lecture notes
29/162
Absorption
Passage of medication from administrative site till its
entry into the systemic circulation.
Determines how soon a drug becomes available to
exert its action
8/11/2019 Pharmacology lecture notes
30/162
Factors that influence absorption
1. Route of administration: IM, Oral, IV
2. Drug form e.g. tablet coating, liquid form,
3. Surface area
4. Blood flow
5. Lipid solubility
8/11/2019 Pharmacology lecture notes
31/162
Absorption of oral drugs
The amount of drug reaching the systemic
circulation is considerably less than the
amount absorbed due to the extraction and
metabolism of the drug by a process called
first pass effect.
8/11/2019 Pharmacology lecture notes
32/162
32
Some of the drug is inactivated and not all will
be available for use at its intended site of
action.
Drugs are therefore formulated to account for
this difference in availability to the tissues.
This is why different forms of drugs are not
equal
Bi il bili
8/11/2019 Pharmacology lecture notes
33/162
Bioavailability
The portion of a dose that reaches
the systemic circulation and is
available to act on body cells.
8/11/2019 Pharmacology lecture notes
34/162
34
IV drugs- 100% bioavailability
Absorption is rapid and 100% bioavailable.
Avoids problems with stomach acid andintestinal absorption issues.
IM drugs
Not as rapid as IV.
Better absorption if there is a good bloodsupply.
Oral drugs
8/11/2019 Pharmacology lecture notes
35/162
Routes that avoid 1stpass effect
Sublingual and Bucal routes
Absorbed into the highly vascularized tissue under
the tongue or between the cheek and the gum-
the oral mucosa
Bypass the liver
Rapidly absorbed.
35
8/11/2019 Pharmacology lecture notes
36/162
Distribution
After a drug is absorbed, the transportation of
that drug from the bloodstream to the body
tissues and intended site of action is called
distribution.
8/11/2019 Pharmacology lecture notes
37/162
Factors Affecting Distribution
Blood supply to site of action: drug is distributed inthis order:
a. Extensive blood supply: heart liver, kidney
b. Areas of slower distribution: skin, fat
c. Bones and brain
Protein binding
Degree of first pass effect.
8/11/2019 Pharmacology lecture notes
38/162
Metabolism
Series of chemical reactions that inactivates a
drug by converting it into watersoluble
compound so that it can be excreted by the
body.
8/11/2019 Pharmacology lecture notes
39/162
39
It takes place mainly in the liver and produces:
1. An inactive metabolite
2. A more soluble compound
3. A more potent metabolite e.g. prodrugs.
Levodopa is a prodrug of dopamine
hydrochloride
8/11/2019 Pharmacology lecture notes
40/162
Other organs or body tissues responsible for metabolism
Liver (mainly)
Skeletal muscle
Kidneys
Lungs
Plasma
Intestinal mucosa
40
8/11/2019 Pharmacology lecture notes
41/162
Factors that decrease (delay) metabolism
Cardiovascular dysfunction
Renal insufficiency
Starvation
Obstructive jaundice
Erythromycin or ketoconazole drug therapy
41
8/11/2019 Pharmacology lecture notes
42/162
Excretion
Removal of drugs from the body.
Drugs and their metabolites can exit the body
in urine, bile, sweat, saliva, breast milk, and
expired air.
The most important organ for drug excretion
is the kidney.
8/11/2019 Pharmacology lecture notes
43/162
Drug excretion
Some drugs are excreted unchanged
Patients who may require dosage
reduction: Patients with kidney disease
Children
older adults
43
8/11/2019 Pharmacology lecture notes
44/162
Half-life of a drug
Time required for the serum
concentration of a drug to decrease by
50% or half of its original concentration.
44
8/11/2019 Pharmacology lecture notes
45/162
Half-life of a drug
Knowledge about drug half-life help in
determining dosing interval
45
8/11/2019 Pharmacology lecture notes
46/162
Pharmacodynamics
Study of what drugs do to the body and how
they do it.
46
8/11/2019 Pharmacology lecture notes
47/162
Drug actions
Drugs usually work in one of four ways:
1. To increase cellular activities.
2. To replace missing chemical3. To slow cellular activities
4. To interfere with the functioning of
foreign cells.
47
8/11/2019 Pharmacology lecture notes
48/162
Receptor theory of drug action
A drug will not act unless it is bound
Most drugs cause their effects by interacting
with specific drug receptors
What are receptors
Structures on a cell
Have chemical structure that matches the shape
and charge of the drug.
Like the relationship btnx a key and lock
48
8/11/2019 Pharmacology lecture notes
49/162
8/11/2019 Pharmacology lecture notes
50/162
Types of drug-receptor interactions
1. Agonist drug
Able to interact and activate receptors
Have two properties
Affinity: ability of a drug to bind to a receptor
Efficacy: tendency of a drug to activate a
receptor once it is bound
50
A t i t d
8/11/2019 Pharmacology lecture notes
51/162
Antagonist drug
Able to interact with receptor but do not change
the receptor
Properties
Have affinity
Have no efficacy
51
8/11/2019 Pharmacology lecture notes
52/162
Types of antagonist drugs
Competitive antagonist
Compete with the agonist drug for the same
receptor site.
Prevents the agonist from binding and therefore
prevents the agonist from causing effect
Effect of competitive antagonist can be overcome
by giving greater dose of the agonist
52
8/11/2019 Pharmacology lecture notes
53/162
Types of antagonist drugs
Non-competitive antagonist
Permanently occupy or change the receptor so
that the agonist cant interact with it.
The effect of non-competitive antagonist cannot
be overcome by increasing the dose of the
agonist.
53
8/11/2019 Pharmacology lecture notes
54/162
The Dose-response relationship
The bigger the dose of a given drug, the
greater the effect
Dose response relationship is dependent on
A. Affinity
B. Efficacy
C. Potency
54
8/11/2019 Pharmacology lecture notes
55/162
Efficacy
The maximum effect produced by a drug.
E.g. if 1 gm of drug A and B are administered to
reduce patients pain and drug A does it at 80%
and drug B does it at 50%, then drug A is said to
be more efficacious than drug B.
8/11/2019 Pharmacology lecture notes
56/162
Potency
Amount of drug that is given to elicit an effect.
A potent drug produces its effect at low doses.
E.g. if 10 mg of drug A is administered and the
effect is 60% and 20mg of drug B produces
same 60% effect, then drug A is said to bemore potent than B.
8/11/2019 Pharmacology lecture notes
57/162
Pain
Definition
Pain is an unpleasant sensory or emotionalexperience related to actual or potential tissue
damage Stimulus for pain
Chemical
Mechanical electrical
thermal
57
Classification of Pain
8/11/2019 Pharmacology lecture notes
58/162
Classification of Pain
Based on duration
Acute pain: a sharp, intense pain of rapid onset
occurring over a short period.
Chronic pain: persistent or intermittent usuallydefined as lasting at least 6 months.
Base on location
Somatic pain: pain arising from body walls Visceral pain:pain arising from organs in the
abdominal and thoracic cavities
58
8/11/2019 Pharmacology lecture notes
59/162
Classification of pain
Referred pain:pain that occurs at the site distant
from the source of the disease or injury, usually of
visceral source.
Phantom limb pain:pain associated with a
missing limb
Emotional or psychogenic pain
59
8/11/2019 Pharmacology lecture notes
60/162
Pathophysiology of pain
1.Transduction
2.Transmission
3.Modulation
4.Perception
8/11/2019 Pharmacology lecture notes
61/162
Transduction
Nociceptorsdetect pain stimuli;
convert them into electrical
impulse .
Histamine, bradykinin,
acetylcholine & serotonin
increase the transmission of
pain. Prostaglandins: increase the
sensitivity of pain receptors.
61
8/11/2019 Pharmacology lecture notes
62/162
Transmission
Movement of pain stimulus from site of injury
to the spinal cord.
This signal travels along:
1. A-delta fibers:
smaller, myelinated & transmit pain signals rapidly
produces the first fast or acute pain
2. Type C fibres
are larger, unmyelinated
transmit the second pain that is normally dull, aching
and burning in quality.
The pain also last longer
8/11/2019 Pharmacology lecture notes
63/162
Modulation
In the spinal cord, the signal
Produce a reflex
gets sent the CNS to be
perceived.
Endogenous opioids (endorphins
and encephalin) modulate intensity
of the signal sent up to the brain.
Perception
8/11/2019 Pharmacology lecture notes
64/162
Perception
Final stop
Occurs in the brain
It is also conscious subjective and emotional.
8/11/2019 Pharmacology lecture notes
65/162
8/11/2019 Pharmacology lecture notes
66/162
Analgesics
Drugs that relieve or reduce pain
without producing
unconsciousness.
2 types
Non-narcotic/NSAIDs
Narcotic analgesics
66
8/11/2019 Pharmacology lecture notes
67/162
8/11/2019 Pharmacology lecture notes
68/162
Non-narcotic analgesics
AKA Cyclooxygenase inhibitors
Group of drugs that relieve pain, fever, and/or
inflammation
E.g. include:
Salicylates
NSAIDs
Acetaminophen
68
Classification of non-narcotic
8/11/2019 Pharmacology lecture notes
69/162
Classification of non-narcotic
analgesics
1. Nonsteroidal anti-inflammatory drugs
Have anti-inflammatory properties
E.g. aspirin, ibuprofen, naproxen, diclofenac
2. Acetaminophen
Reduce pain and fever but cant suppress
inflammation
E.g. Tylenol or paracetamol
8/11/2019 Pharmacology lecture notes
70/162
Mechanism of action
Inactivates cyclooxygenases (enzyme required
for prostaglandin formation)
Two forms of cyclooxygenases
COX-1
COX-2
70
8/11/2019 Pharmacology lecture notes
71/162
Cox-1
Present in all tissues/cells
Functions:
blood clotting
protect stomach lining,
Decrease gastric secretion,
increase mucus secretion.
Inhibition: adverse effects of NSAIDs
71
8/11/2019 Pharmacology lecture notes
72/162
Cox-2
Active at sites of trauma, or injury and is
associated with pain and other signs of
inflammation.
Inhibition of COX-2 results in therapeutic
effects
72
8/11/2019 Pharmacology lecture notes
73/162
Non-steroidal anti-inflammatory
drugs (NSAIDs)
8/11/2019 Pharmacology lecture notes
74/162
Introduction
A non-narcotic analgesic
So named because they dont belong to the
steroids group
Yet have anti-inflammatory & analgesic
properties
74
8/11/2019 Pharmacology lecture notes
75/162
Classification of NSAIDs
First-generation NSAIDs
Inhibit COX-1 and COX-2
E.g. aspirin, ibuprofen and naproxen.
Second Generation NSAIDs:
Inhibit COX-2 only.
Inhibit pain and inflammation with minimal risk
of serious side effects. E.g. celecoxib.
8/11/2019 Pharmacology lecture notes
76/162
Examples of NSAIDs
Salicylates
Ibuprofen
Naproxen
Diclofenac sodium
Indometacin
Celecoxib perixicam
8/11/2019 Pharmacology lecture notes
77/162
Salicylates
Pharmacologic Effects
1. Analgesic
2. Antipyretic
3. Anti-inflammatory
77
f
8/11/2019 Pharmacology lecture notes
78/162
Types of Salicylates
Aspirin (acetylsalicylic acid)
Magnesium salicylate
Sodium salicylate
All have similar in pharmacologic activity ( aspirin
has greater anti- inflammatory effect
Aspirin (acetylsalicylic acid): a
8/11/2019 Pharmacology lecture notes
79/162
Aspirin (acetylsalicylic acid): a
prototype
Generic name:aspirin
Trade names:Ecotrin,
Classification:Antipyretic, Analgesic (non-
opioid), anti-inflammatory, anitrheumatic,
antiplatelet, salicylate and NSAID
h i i
8/11/2019 Pharmacology lecture notes
80/162
Therapeutic actions
1. Suppression of inflammation:rheumatoid arthritis and
osteoarthritis.
2. Analgesia:mild to moderate pain e.g. headache &
dysmenorrhea
3. Reduction of fever: Inhibits pyrogen-induced synthesis
of prostaglandins.
h i i
8/11/2019 Pharmacology lecture notes
81/162
Therapeutic actions
4. Dysmenorrhea:Inhibits prostaglandin
synthesis in the uterine smooth muscles.
5. Suppression of platelet aggregation
Synthesis of thromboxane A2 (TXA2) in the
platelet promotes aggregation.
Aspirin causes an irreversible inhibition of COX-1,
the enzyme that makes TXA2.
D
8/11/2019 Pharmacology lecture notes
82/162
Dosages
Aches and pains; fever: 325-650mg q 4 hrs.
Acute rheumatic fever: 5-6gm/day/ divided doses
Rheumatoid arthritis: 3.6-5.4mg /day/divided doses
Acute MI: 160mg once a day
Ischemic stroke/TIAs 50-325mg once a day
Routes: Oral and Rectal
Ad ff
8/11/2019 Pharmacology lecture notes
83/162
Adverse effects
GIT disturbances: e.g. dyspepsia andvomiting.
Bleeding: due to inhibition of platelet
aggregation. Renal impairment: inhibits synthesis of
prostaglandins that cause vasodilation. Theresultant vasoconstriction decreases renal
blood flow to the kidneys
Allergy:
Ad ff
8/11/2019 Pharmacology lecture notes
84/162
Adverse effects
Salicylism
A syndrome: occurs when aspirin levels climb just
slightly above therapeutic levels.The symptoms
include:Dizziness& Tinnitus Reyes syndrome (rare but serious)
Characterized by encephalopathy and fatty liver
degeneration. Observed in children with influenza or chickenpox
& taking aspirin.
C t i di ti
8/11/2019 Pharmacology lecture notes
85/162
Contraindication
1. Hemophilia
2. Children under 12 years
3. GIT ulceration
4. aspirin intolerance
5. breastfeeding
Ad ff t
8/11/2019 Pharmacology lecture notes
86/162
Adverse effects GIT disturbances
Salicylate toxicity produces a condition calledsalicylism. The symptoms include:
Dizziness
Tinnitus
Impaired hearing
Nausea
Vomiting Mental confusion.
86
t i di ti
8/11/2019 Pharmacology lecture notes
87/162
contraindication
Heamophillics
Chdn under 12 yrs
GIT ulceration
Breastfeeding
87
Ib f
8/11/2019 Pharmacology lecture notes
88/162
Ibuprofen
Generic Name: ibuprofen
Trade/brand name: ????
Classification: NSAID, Analgesic (non-opioid),
priopionic acid derivative
Dosage
8/11/2019 Pharmacology lecture notes
89/162
Therapeutic action
Exhibits anti-inflammatory, analgesic and
antipyretic properties
Has both central and peripheral effects
Indications
Relief S/S of rheumatoid arthritis
Relief of mild to moderate pain Fever reduction
Sid ff t
8/11/2019 Pharmacology lecture notes
90/162
Side effects Dyspepsia
vomiting,
abdominal pains,
heartburns,
nausea,
Diarrhoea Severe GI bleeding and Unceration
C t i di ti
8/11/2019 Pharmacology lecture notes
91/162
Contraindications
1. Peptic Ulcer disease
2. Hypersensitivity
3. Neonates with congenital heart disease
4. Active bleeding
Acetaminophen
8/11/2019 Pharmacology lecture notes
92/162
Acetaminophen
Generic name acetaminophen
Trade/Brand name Paracetamol, Tylenol,
Panadol
Mechanism of action
8/11/2019 Pharmacology lecture notes
93/162
Mechanism of action
Inhibition of prostaglandins by Paracetamol
occurs ONLY IN THE CNS.
Has no effect on prostaglandin synthesis in the
peripheral sites.
This may explain the absence of anti-inflammatory effects and gastric ulceration.
Indications
8/11/2019 Pharmacology lecture notes
94/162
Indications
Relief of pain and fever
It is preferred to NSAIDs for use in children
suspected of having chicken pox and influenza
Good replacement for patients with aspirin
toxicity
8/11/2019 Pharmacology lecture notes
95/162
Dosages:
Adult and children over 12 yrs325mg to 650mg q 4 to 6 hrs.
Pediatric patients
0-3 months 62.5mg 4-11 months 125mg
12-23 months 187.5mg
2-3 years 250mg
4-5yrs 375mg
6-7 yrs 500mg
Metabolism of acetaminophen
8/11/2019 Pharmacology lecture notes
96/162
Acetaminophen can be metabolized in two ways;1. Major pathway:
Acetaminophen undergoes conjugation with glucuronic acid to form nontoxic metabolites.
At therapeutic doses, practically the entire drug is converted to nontoxic compounds via themajor pathway.
2. Minor pathway : Acetaminophen is oxidized by P450-containing enzyme into highly reactive and toxic
compound. Only a small fraction is converted into toxic metabolite via the minor pathway.
Under normal conditions, the toxic metabolite undergoes rapid conversion to a nontoxicform; glutathione is required for the conversion.
When an overdose of acetaminophen is taken, a larger than normal amount is processed viathe minor pathway; hence, a large quantity of toxic metabolite is produced.
As the liver attempts to detoxify the metabolite, glutathione is rapidly depleted, and furtherdetoxification stops. As a result, the toxic metabolite accumulates, causing damage to the
liver.
8/11/2019 Pharmacology lecture notes
97/162
Opioids (Narcotic) Analgesics
8/11/2019 Pharmacology lecture notes
98/162
Opioids (Narcotic) Analgesics
Two classes:
Narcotic analgesics obtained from raw opium
Synthetic narcotic analgesics
98
Narcotic Analgesics
8/11/2019 Pharmacology lecture notes
99/162
Narcotic Analgesics Terminologies
Opiates: compounds extracted from the opium
poppy flower
opioids: chemical compounds that are wholly
synthesized, but which resemble the opiates in
their actions e.g. meperidine
Other Examples: morphine and codeine.
99
General properties of narcotic analgesics
8/11/2019 Pharmacology lecture notes
100/162
General properties of narcotic analgesics
They have capacity to reduce pain and painperception
Able to alter ones reaction to the pain
They have sedative properties
They cause profound feeling well-being
(euphoria)
Addictive properties (physical and
psychological dependence)
Examples of Narcotic Analgesics
8/11/2019 Pharmacology lecture notes
101/162
(Opiates & Opioids)
Strong opioid
Morphine sulfate
Pethidine Hydrocloride (meperidine)
Fentanyl
butorphanol,
Levophanol
Mild opioid
Tramadol HCL
Codeine phosphate101
Prototype: Morphine sulfate
8/11/2019 Pharmacology lecture notes
102/162
Prototype: Morphine sulfate
Generic name
Morphine sulfate
Trade name:
???
Classification:
Opioid agonist analgesic
Dosage and route
8/11/2019 Pharmacology lecture notes
103/162
Dosage and route
Oral 15mg PO daily, as a single dose in the evening
IM or Subcutaneous
5-20mg/70kg as directed by physician
IV
2.5-15/70kg of body weight
8/11/2019 Pharmacology lecture notes
104/162
Effects of morphine
8/11/2019 Pharmacology lecture notes
105/162
analgesia,
sedation,
euphoria,
respiratory depression, cough suppression and
suppression of bowel motility.
105
Indication
8/11/2019 Pharmacology lecture notes
106/162
Severe acute pain or severe chronic pain.
Preoperative sedation and adjunct to anesthesia
control of pain associated with acute myocardial
infarction
Relieve of severe, persistent cough
Treatment of severe diarrhea and intestinal cramping.
106
Contraindication
8/11/2019 Pharmacology lecture notes
107/162
Hypersensitivity
Addiction
Hemorrhage
Bronchial asthma
Increased intracranial pressure
107
Adverse Effects
8/11/2019 Pharmacology lecture notes
108/162
Read from hand out
108
8/11/2019 Pharmacology lecture notes
109/162
DRUGS USED IN THE PERIOPERATIVE
PERIOD
109
Introduction
8/11/2019 Pharmacology lecture notes
110/162
Introduction
These drugs are CNS depressants.
Classified into:
General anesthetic agents,
Narcotic analgesics
Sedative-Hypnotics.
110
Preoperative agents: Sedative-hypnotics
8/11/2019 Pharmacology lecture notes
111/162
Preoperative agents: Sedative hypnotics
Definitions
Anxiolytics: drugs that prevent feeling of tension or fear.
Sedatives: provide a calming effect on patients
Hypnotics: induces sleep.
Sedative-hypnotic:Produces calming effect at lower doses
and induce sleep at higher doses.
111
8/11/2019 Pharmacology lecture notes
112/162
Sedative-hypnoticsare grouped as:
barbiturates
benzodiazepines
Barbiturates
8/11/2019 Pharmacology lecture notes
113/162
Barbiturates
They are powerful CNS
depressants
Rarely used because of:
side effects
risk of psychological
and physical
dependence.
Mechanism of action
8/11/2019 Pharmacology lecture notes
114/162
Act on the brainstem in the reticular activating
system (RAS) by:
inhibiting nerve cell function
reducing nerve impulse transmission to the
cerebral cortex.
Raising the seizure convulsive threshold.
8/11/2019 Pharmacology lecture notes
115/162
Drug
name
Dosage/Route Adverse effects
Pheno
barbita
l
(lumin
al)
Sedative: oral; 30-120mg /day
IV/IM; 100-200mg/day
Drowsiness, vitamin
deficiency (vit. D;
folate, or B12)
Pentob
arbital
Sedative: oral; 20-30mg bid or qid
Hypnotic: oral; 120-200mg;IM,
150-200mg
Respiratory
depression,
laryngospasm
8/11/2019 Pharmacology lecture notes
116/162
PRINCIPLES OF DRUG
DMINISTR TION
OVERVIEW
8/11/2019 Pharmacology lecture notes
117/162
OVERVIEW
Drugs given for therapeutic purposes arecalled medications.
Administering medications-an important
nursing responsibility The basic requirements for accurate drug
administration are often called the five
rights and the three checks
THE THREE CHECKS
8/11/2019 Pharmacology lecture notes
118/162
THE THREE CHECKS
The label on the medication container shouldbe checked three times during medicationpreparation.
The label should be read: when the nurse reach for the container
Immediately before pouring or opening themedication
When replacing the container to the drawer orshelf
The five rights
8/11/2019 Pharmacology lecture notes
119/162
The five rights
The right medication to the
Right patient in the
Right dosage through the
Right route at the
Right time
LEGAL RESPONSIBILTIES
8/11/2019 Pharmacology lecture notes
120/162
LEGAL RESPONSIBILTIES
Registered Nurses are legally empowered, togive medications ordered
When giving medications, the nurse is legally
responsible for safe and accurate administration. She may be held liable for not giving a drug or for
giving a wrong drug or a wrong dose.
she is expected to have sufficient drug knowledge
to recognize and question erroneous orders.
LEGAL RESPONSIBILTIES
8/11/2019 Pharmacology lecture notes
121/162
LEGAL RESPONSIBILTIES
The nurse also is legally responsible for actionsdelegated to people who are inadequately
prepared for or legally barred from
administering medications (such as nursingassistants).
nurses are expected to
monitor clients responses to drug therapy. to teach clients safe and effective self-
administration of drugs when indicated
All substances are poisons;
8/11/2019 Pharmacology lecture notes
122/162
p ;
there is none that is not apoison. The right dosedifferentiates a poison froma remedy.
Paracelsus, 1493-1541
Ideal Drug
8/11/2019 Pharmacology lecture notes
123/162
g
Effectiveness
Safety
Selectivity
Reversible
Predictability
Ease of administration
Freedom from drug interactions
Ideal Drug
8/11/2019 Pharmacology lecture notes
124/162
g
Low cost
Chemical Stability
Possession of a simple generic name
8/11/2019 Pharmacology lecture notes
125/162
8/11/2019 Pharmacology lecture notes
126/162
PHARMACOKINETICS
8/11/2019 Pharmacology lecture notes
127/162
Therapeutic Objective
8/11/2019 Pharmacology lecture notes
128/162
p j
Maximum benefit with minimum harm
The intensity of the response to a drug is
directly related to the concentration of the
drug at its site of action
Intensity of Drug responses
8/11/2019 Pharmacology lecture notes
129/162
y g p
Administrationdosage and route
Pharmacokinetics
Pharmacodynamics
Individual variation
Nursing Responsibilities
8/11/2019 Pharmacology lecture notes
130/162
g p
Last line of defense against errors!!!!!!!!!
Patient education
Utilize the nursing process
Drug Legislation
8/11/2019 Pharmacology lecture notes
131/162
g g
1906drugs should be free of adulterants
1938testing for toxicity
1962proof of effectiveness
1970Controlled Substance ActScheduled
drugs
1997Food and Drug Administration
Modernization Act
New Drug Development
8/11/2019 Pharmacology lecture notes
132/162
g p
Preclinical testingprior to testing on humans
Clinical testing
Inormal volunteersexcept maybe patients
who have disease
II and IIIpatients
IVreleased for general use
8/11/2019 Pharmacology lecture notes
133/162
Be neither the first to adopt the new nor thelast to abandon the old!
Drug Names
8/11/2019 Pharmacology lecture notes
134/162
Chemical Generic Name
Trade Name
OTC drugs
Pharmacokinetics
8/11/2019 Pharmacology lecture notes
135/162
Drug movement throughout the body
Absorptionmovement of drug from its site ofadministration into blood
Dissolvemust dissolve before being absorbed
Surface areathe larger the faster
Blood flowmost rapid where blood flow is high
Lipid solubility - the higher the faster
pH partitioning
Absorption - Routes
8/11/2019 Pharmacology lecture notes
136/162
IVno barriers to absorption Intramusculargood for poorly soluble drugs, time
released
Subcutaneousagain no significant barriers Oralmust pass through cells of epithelium, enteric
coating
Safer but highly variable absorptionenteric,
sustained-release, tablets
Distribution
8/11/2019 Pharmacology lecture notes
137/162
Blood flow to tissues Exiting the vascular system once it has been
deliveredpass through pores in capillary
wall
Protein - binding
8/11/2019 Pharmacology lecture notes
138/162
Drugs can bind with proteins Parts of drugs will be bound during any given
time period
Impedes drugs ability to reach sites of action,metabolism, or excretion
Metabolism
8/11/2019 Pharmacology lecture notes
139/162
LIVER Enzymatic alteration of drug structure
Consequences of metabolism
8/11/2019 Pharmacology lecture notes
140/162
Accelerated renal excretionkidney cannotexcrete highly lipid soluble
Drug inactivation
Increased therapeutic action
Activation of prodrugs
Increased or decreased toxicity
Considerations in Metabolism
8/11/2019 Pharmacology lecture notes
141/162
Age Induction of drug metabolizing enzymes
First-pass effectNitroglycerin
Nutritional status
Competition between drugs
Excretion
8/11/2019 Pharmacology lecture notes
142/162
KIDNEY Glomerular filtrationblood to tubular urine
Tubular reabsorption
Active tubular secretionpumps for organic
acids and organic basesto urine
Monitoring drug levels
8/11/2019 Pharmacology lecture notes
143/162
Plasma drug levels
Therapeutic range
Drug Half-life
8/11/2019 Pharmacology lecture notes
144/162
Time requires for the amount of drug in thebody to decrease by 50%
Will determine dosing requirements
Goal - plateau
Dosing
8/11/2019 Pharmacology lecture notes
145/162
Loading doseswhen plateau must beachieved quickly
Routine smaller dosesmaintenance doses
8/11/2019 Pharmacology lecture notes
146/162
Peak and trough levels
8/11/2019 Pharmacology lecture notes
147/162
Maximal efficacylargest effect a drug canproduce
Potencyone that produces its effects at
lower dosages
Receptors
8/11/2019 Pharmacology lecture notes
148/162
Drugs bind to receptors to produce effects
Reversible
8/11/2019 Pharmacology lecture notes
149/162
All that drugs can do is mimic the physiologicalactivity of the bodys own molecules
Block the physiological activity of the bodys
own molecules
Agonists
8/11/2019 Pharmacology lecture notes
150/162
Mimic the bodys own regulatory molecules
Antagonists
8/11/2019 Pharmacology lecture notes
151/162
Drugs that block the actions of endogenousregulators
Partial agonists
8/11/2019 Pharmacology lecture notes
152/162
Mimic the actions but with reduced intensity
Drug Interactions
8/11/2019 Pharmacology lecture notes
153/162
Can have varying effects
Direct chemical or physicalIV preparation
DrugFood Interactions
8/11/2019 Pharmacology lecture notes
154/162
Frequently decreased rate of absorption
Grapefruit juice can inhibit metabolism
with food with or shortly after meal
empty stomach one hour prior to meal or
two hours after
Adverse drug reactions
8/11/2019 Pharmacology lecture notes
155/162
Side effect Toxicity
Allergic reaction
Idiosyncratic effect
Iatrogenic disease
Physical dependence
Carcinogenic effect
8/11/2019 Pharmacology lecture notes
156/162
Teratogenic effectinduce birth defect
Ways to minimize
Variation in drug responses
8/11/2019 Pharmacology lecture notes
157/162
Age Body composition
Gender
Pathophysiology
Tolerance Placebo effect
Genetics
Variability in absorptionbioavailabilityoral
ability to reach circulation Compliance
8/11/2019 Pharmacology lecture notes
158/162
What does the term adverse reaction refer to?
A. A life-threatening response to a responseto a drug
B. A drug-induced allergy C. A harmful, undesirable response to a drug
D. An unpredictable response to a drug
8/11/2019 Pharmacology lecture notes
159/162
What is an idiosyncratic response? A. a toxic reaction
B. an allergic reaction
C. a reaction peculiar to the patient
D. an anaphylactic reaction
8/11/2019 Pharmacology lecture notes
160/162
Which statement accurately characterizes geriatricpatients compliance with prescribed drug regimens?
A. compliance decreases with age
B. compliance increases with age
C. compliance increases with multiple healthproblems
D. compliance decreases when more than threedrugs are prescribed
8/11/2019 Pharmacology lecture notes
161/162
8/11/2019 Pharmacology lecture notes
162/162