Pharmacology lecture notes

8/11/2019 Pharmacology lecture notes

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Pharmacology and

Therapeutics

Lecturer:Isaac Amankwaa


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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.


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COURSE CONTENT

1. Sources of drugs

2. General drug metabolism

3. Analgesics4. Anaesthesics

5. Tranquilizers: major and minor

6. Antidepressants7. Anticholinergics


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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


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Course content CTD

Antimetabolites

Eye preparations

Ear preparations Drugs acting on the endocrine system


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TERMINOLOGIES


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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?


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TERMINOLOGIES


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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.


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THERAPEUTICS

The use of drug to diagnose,

prevent or treat diseases or to

prevent pregnancy


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Clinical Pharmacology

The study of drugs in humans-

includes the study of drugs in

patients as well as healthyvolunteers


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A drug/Medication:

A chemical used in the diagnosis,

treatment, or prevention of disease.

They are used interchangeably.


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Sources of drugs

Two main sources:1. Natural

2. Synthetic


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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).


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Drug names

A drug may have about four names:.

1. Chemical name

2. Generic name (nonproprietary)

3. Official name

4. Trade name


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Types of drug names Examples

Chemical name N-Acetyl-para-aminophenol

Generic name acetaminophen

Trade names Paracetamol, Tylenol, EFPAC


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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


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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.


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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


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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


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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


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Science

of Pharma-cology

Pharmacognosy

Pharmacokinetics

Pharmacodynamics

PharmacotherapeuticsToxicology


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EFFECTS OF DRUGS

Drugs are given for two effects:

Local effects

Systemic effect

Both can further be grouped into

desirable and

Undesirable effects


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PRINCIPLES OF PHARMACOLOGY

Chapter Two

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1. Pharmacokinetics

2. Pharmacodynamics


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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.


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Components of PK.

Absorption (A)

Distribution (D)

Metabolism (M)

Excretion (E)

ADME


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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


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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


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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.


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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


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Bioavailability

The portion of a dose that reaches

the systemic circulation and is

available to act on body cells.


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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


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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.

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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.


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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.


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Metabolism

Series of chemical reactions that inactivates a

drug by converting it into watersoluble

compound so that it can be excreted by the

body.


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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


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Other organs or body tissues responsible for metabolism

Liver (mainly)

Skeletal muscle

Kidneys

Lungs

Plasma

Intestinal mucosa

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Factors that decrease (delay) metabolism

Cardiovascular dysfunction

Renal insufficiency

Starvation

Obstructive jaundice

Erythromycin or ketoconazole drug therapy

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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.


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Drug excretion

Some drugs are excreted unchanged

Patients who may require dosage

reduction: Patients with kidney disease

Children

older adults

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Half-life of a drug

Time required for the serum

concentration of a drug to decrease by

50% or half of its original concentration.

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Half-life of a drug

Knowledge about drug half-life help in

determining dosing interval

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Pharmacodynamics

Study of what drugs do to the body and how

they do it.

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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.

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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

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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

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A t i t d


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Antagonist drug

Able to interact with receptor but do not change

the receptor

Properties

Have affinity

Have no efficacy

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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

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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.

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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

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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.


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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.


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Pain

Definition

Pain is an unpleasant sensory or emotionalexperience related to actual or potential tissue

damage Stimulus for pain

Chemical

Mechanical electrical

thermal

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Classification of Pain


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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

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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

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Pathophysiology of pain

1.Transduction

2.Transmission

3.Modulation

4.Perception


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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.

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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


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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


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Perception

Final stop

Occurs in the brain

It is also conscious subjective and emotional.


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Analgesics

Drugs that relieve or reduce pain

without producing

unconsciousness.

2 types

Non-narcotic/NSAIDs

Narcotic analgesics

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Non-narcotic analgesics

AKA Cyclooxygenase inhibitors

Group of drugs that relieve pain, fever, and/or

inflammation

E.g. include:

Salicylates

NSAIDs

Acetaminophen

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Classification of non-narcotic


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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


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Mechanism of action

Inactivates cyclooxygenases (enzyme required

for prostaglandin formation)

Two forms of cyclooxygenases

COX-1

COX-2

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Cox-1

Present in all tissues/cells

Functions:

blood clotting

protect stomach lining,

Decrease gastric secretion,

increase mucus secretion.

Inhibition: adverse effects of NSAIDs

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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

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Non-steroidal anti-inflammatory

drugs (NSAIDs)


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Introduction

A non-narcotic analgesic

So named because they dont belong to the

steroids group

Yet have anti-inflammatory & analgesic

properties

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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.


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Examples of NSAIDs

Salicylates

Ibuprofen

Naproxen

Diclofenac sodium

Indometacin

Celecoxib perixicam


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Salicylates

Pharmacologic Effects

1. Analgesic

2. Antipyretic

3. Anti-inflammatory

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f


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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


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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


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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.

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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


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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


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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


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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


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Contraindication

1. Hemophilia

2. Children under 12 years

3. GIT ulceration

4. aspirin intolerance

5. breastfeeding

Ad ff t


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Adverse effects GIT disturbances

Salicylate toxicity produces a condition calledsalicylism. The symptoms include:

Dizziness

Tinnitus

Impaired hearing

Nausea

Vomiting Mental confusion.

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t i di ti


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contraindication

Heamophillics

Chdn under 12 yrs

GIT ulceration

Breastfeeding

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Ib f


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Ibuprofen

Generic Name: ibuprofen

Trade/brand name: ????

Classification: NSAID, Analgesic (non-opioid),

priopionic acid derivative

Dosage


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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


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Side effects Dyspepsia

vomiting,

abdominal pains,

heartburns,

nausea,

Diarrhoea Severe GI bleeding and Unceration

C t i di ti


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Contraindications

1. Peptic Ulcer disease

2. Hypersensitivity

3. Neonates with congenital heart disease

4. Active bleeding

Acetaminophen


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Acetaminophen

Generic name acetaminophen

Trade/Brand name Paracetamol, Tylenol,

Panadol

Mechanism of action


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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


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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


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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


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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.


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Opioids (Narcotic) Analgesics


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Opioids (Narcotic) Analgesics

Two classes:

Narcotic analgesics obtained from raw opium

Synthetic narcotic analgesics

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Narcotic Analgesics


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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.

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General properties of narcotic analgesics


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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


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(Opiates & Opioids)

Strong opioid

Morphine sulfate

Pethidine Hydrocloride (meperidine)

Fentanyl

butorphanol,

Levophanol

Mild opioid

Tramadol HCL

Codeine phosphate101

Prototype: Morphine sulfate


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Prototype: Morphine sulfate

Generic name

Morphine sulfate

Trade name:

???

Classification:

Opioid agonist analgesic

Dosage and route


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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


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Effects of morphine


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analgesia,

sedation,

euphoria,

respiratory depression, cough suppression and

suppression of bowel motility.

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Indication


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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.

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Contraindication


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Hypersensitivity

Addiction

Hemorrhage

Bronchial asthma

Increased intracranial pressure

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Adverse Effects


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Read from hand out

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DRUGS USED IN THE PERIOPERATIVE

PERIOD

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Introduction


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Introduction

These drugs are CNS depressants.

Classified into:

General anesthetic agents,

Narcotic analgesics

Sedative-Hypnotics.

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Preoperative agents: Sedative-hypnotics


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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.

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Sedative-hypnoticsare grouped as:

barbiturates

benzodiazepines

Barbiturates


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Barbiturates

They are powerful CNS

depressants

Rarely used because of:

side effects

risk of psychological

and physical

dependence.

Mechanism of action


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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.


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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


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PRINCIPLES OF DRUG

DMINISTR TION

OVERVIEW


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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


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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


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The five rights

The right medication to the

Right patient in the

Right dosage through the

Right route at the

Right time

LEGAL RESPONSIBILTIES


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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.



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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;


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p ;

there is none that is not apoison. The right dosedifferentiates a poison froma remedy.

Paracelsus, 1493-1541

Ideal Drug


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g

Effectiveness

Safety

Selectivity

Reversible

Predictability

Ease of administration

Freedom from drug interactions

Ideal Drug


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g

Low cost

Chemical Stability

Possession of a simple generic name


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PHARMACOKINETICS


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Therapeutic Objective


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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


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y g p

Administrationdosage and route

Pharmacokinetics

Pharmacodynamics

Individual variation

Nursing Responsibilities


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g p

Last line of defense against errors!!!!!!!!!

Patient education

Utilize the nursing process

Drug Legislation


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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


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g p

Preclinical testingprior to testing on humans

Clinical testing

Inormal volunteersexcept maybe patients

who have disease

II and IIIpatients

IVreleased for general use


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Be neither the first to adopt the new nor thelast to abandon the old!

Drug Names


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Chemical Generic Name

Trade Name

OTC drugs

Pharmacokinetics


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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


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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


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Blood flow to tissues Exiting the vascular system once it has been

deliveredpass through pores in capillary

wall

Protein - binding


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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


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LIVER Enzymatic alteration of drug structure

Consequences of metabolism


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Accelerated renal excretionkidney cannotexcrete highly lipid soluble

Drug inactivation

Increased therapeutic action

Activation of prodrugs

Increased or decreased toxicity

Considerations in Metabolism


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Age Induction of drug metabolizing enzymes

First-pass effectNitroglycerin

Nutritional status

Competition between drugs

Excretion


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KIDNEY Glomerular filtrationblood to tubular urine

Tubular reabsorption

Active tubular secretionpumps for organic

acids and organic basesto urine

Monitoring drug levels


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Plasma drug levels

Therapeutic range

Drug Half-life


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Time requires for the amount of drug in thebody to decrease by 50%

Will determine dosing requirements

Goal - plateau

Dosing


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Loading doseswhen plateau must beachieved quickly

Routine smaller dosesmaintenance doses


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Peak and trough levels


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Maximal efficacylargest effect a drug canproduce

Potencyone that produces its effects at

lower dosages

Receptors


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Drugs bind to receptors to produce effects

Reversible


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All that drugs can do is mimic the physiologicalactivity of the bodys own molecules

Block the physiological activity of the bodys

own molecules

Agonists


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Mimic the bodys own regulatory molecules

Antagonists


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Drugs that block the actions of endogenousregulators

Partial agonists


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Mimic the actions but with reduced intensity

Drug Interactions


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Can have varying effects

Direct chemical or physicalIV preparation

DrugFood Interactions


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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


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Side effect Toxicity

Allergic reaction

Idiosyncratic effect

Iatrogenic disease

Physical dependence

Carcinogenic effect


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Teratogenic effectinduce birth defect

Ways to minimize

Variation in drug responses


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Age Body composition

Gender

Pathophysiology

Tolerance Placebo effect

Genetics

Variability in absorptionbioavailabilityoral

ability to reach circulation Compliance


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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


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What is an idiosyncratic response? A. a toxic reaction

B. an allergic reaction

C. a reaction peculiar to the patient

D. an anaphylactic reaction


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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


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