INTRODUCTION TO

PHARMACOLOGY

Syed Yousaf Shah

Lecturer

Institute of Nursing

DUHS

 GRADE / GPA REQUIREMENT FOR EACH SEMESTER & GRADUATION

Assessment

Pattern (formative and summative) Criteria for formative assessment : Attendance class participation quizzes,

Assignment and presentation. Internal evaluation 30%

Criteria for Summative : Midterm 30% weightage (Conducted by

Examination Department) End of semester 40 % weightage Overall assessment 100 % weightage

TEACHING/LEARNINGSTRATEGIES

Lecture/tutorials/handouts, self-directed learning, drug cards and quiz.

PHARMACOLOGY-Is.# Topic Date1 Introduction to Pharmacology 9-11-13

2 Introduction to Pharmacology 16-11-13

3 Introduction to Pharmacology 23-11-13

4 Introduction to Pharmacology Quiz I (5%) 30-11-13

5 Drugs Used to Treat and Prevent Infections 7-12-13

6 Drugs Used to Treat and Prevent Infections Assignment I(5%) 14-12-13

7 Drugs Used to Treat and Prevent Infections 21-12-13

8 Drugs Affecting the Gastrointestinal System 28-12-13

9 Drugs Affecting the Gastrointestinal System 04-12-13

10 Midterm 30%11 Drugs Affecting Haematology System 12 Drugs Affecting Haematology System 13 Drugs Affecting Haematology System Quiz II (5%)14 Anti-neoplastic-Drugs 15 Anti-neoplastic-Drugs Assignment II (5%)16 Anti-neoplastic-Drugs 17 Presentation & submission (10%)18 Final Exam 40%

References:

1. Aucker, L. (2001). Pharmacology and the nursing process. (3rd ed.). London: Mosby.

2. Boyer, M. J. (2002). Math for nurses. (5th ed.). Philadelphia: Lippincott.

3. Bruegal, C. (2003). Staying a step ahead of migraines. Nursing 33, (11), pp.56-58.

4. Clayton, B. D. & Stock, Y. N. ((2001). Basic pharmacology for nurses. 12th ed London: Mosby.

5. Clayton, B. D. & Stock, Y. N. (2001). Drugs used to treat glaucoma and other eye disorders. In (12th ed.). Basic pharmacology for nurses. (pp. 430 - 468). London: Mosby.

6. Dosage calculations: Made incredibly easy (2001). (2nd ed). London: Saunders

LEARNING OBJECTIVES

Define drug and pharmacology Discuss the terminologies related to

pharmacology Discuss the history of pharmacology briefly Briefly discuss routes of administration. Identify the purposes of medication Identify the source of medication Discuss the classification of drugs Describe the three type of drug supply system. Discuss the drugs standards and legislation. Identify resource to collect and utilize drug

information.

PHARMACOLOGY

“A branch of medical sciences that study

drugs and their action on living

organisms”

DRUG

“Any substance that brings about a change in biologic

function through its chemical actions

DRUG

“chemical substance used in the treatment, cure,

prevention, or diagnosis of disease or used to

otherwise enhance physical or mental well-being."

HISTORY OF PHARMACOLOGY

Chinese medicine – oldest Sumerian tablet – ointment and medicines

containing potassium nitrate, asafoetida. Eberspapyrus more than 700

pharmacopeal documents including beer,turpentine,berries,poppy,lead,salt & crushed precious stones etc.(Egyptian remedies).

Hippocrates – Father of medicine. Aristotle – separated Superstition from fact Paracelsus – mercurials in syphilis Francois megendiea – concept of scientific

methods in drug study.

Ostwald schimiedorg , jacob abel – modern for experimental Pharmacology.

WHY DO NURSES STUDY PHARMACOLOGY??

“ To safely administer medications and to monitor patients who receive these

medications”

GENERAL CLASSIFICATION OF DRUG

Prescription Drugs Official Drugs OTC Drugs Controlled Drugs High Alert Medications

Therapeutic Classification

Analgesics Anxiolytics Anesthetics Anti- Asthmatics Antiinfectives Antibacterials Antivirals Antifungal AntiTuberculer Drug

Antimalarials Antacids Antiacne Antihypertensives Antianginal Antiarrythmics Antiinflammatory Hypolipidemics Antiepileptics Antiemetics Antidiarrheal Antihistamines

RELATED DEFINITION

Receptor “A specific protein in either the plasma membrane or interior of a target cell with which a chemical messenger/drug combines”

Mechanism of Action “The ways by which drugs can produce therapeutic effects”

Dose “The amount of a drug to be administered at one time”

Indications “The reasons for administering amedication or performing a treatment”

Contra-indications “Factor that prevents the use of a

medication or treatment (e.g., Allergies)”

Pharmacology, Definitions

Effects (therapeutic effect) “The desired results of

administration of a medication” Side Effects (adverse

effects)“Effects that are harmful and undesired, and that occur in addition to the desired therapeutic effects”

Duration“The time a drug concentration is sufficient to elicit a therapeutic response”

Onset“The time it takes for the drug to elicit a therapeutic response”

FIVE R’s

DRUG SOURCES

1.Plant Sources: Examples include digoxin from digitalis and

morphine from opium.2.Animal Sources: Glandular products from

animals are used, such as insulin and thyroid.3.From micro-organisms (fungi, bacteria)

Penicillin was discovered by Alexander Fleming in 1928 as a product of penicillium notatum (a mold growing in his lab)

Mineral Sources: from minerals, for example, lithium carbonate (an antipsychotic), MgSO4 (a laxative)

Synthetic Sources:Examples include sulfonamides, and aspirin.

Recombinant proteins: such as interferons, antibodies

SOURCES OF DRUG INFORMATION

Text books Materia medica Pharmacopea Formulary Journals Pharmacists

Drug Nomenclature

the chemical name 2-methyl-5-nitroimidazole-l-ethanol is metronidazole. The word methylnitro is condensed to metro and ni-dazole is due to its imidazole ring

Chemical name - represents the exact description of the drug’s chemical composition

Generic name (non-proprietary)

- simpler than the chemical name and - derived from the chemical name itself - easier to remember

Brand or trade name (proprietary) is developed by the company requesting approval for the drug and identifies it as the exclusive property of that company. Flagyl® is the trade name for metronidazole. Metoclon® is the trade name for Metoclopramide. Amoxil® is the trade name for amoxycillin. Panadol® is the trade name for Acetaminophene.

Pregnancy Categories

Category A-studies in pregnant women failed to show risk to the fetus

Category B- animal studies have failed to show a risk to the fetus but there are no adequate studies in women

Category C-animal studies have shown an adverse effect on the fetus, no adequate human studies, benefits may outweigh risks

Pregnancy Categories

Category D-positive evidence of human fetal risk.

Category X-animal or human studies have shown fetal abnormalities or toxicity

DRUG BODY INTERACTION

PHARMACOKINETICS

What the Body Does with the DRUG

PHARMACODYNAMICS

What the Drug Does to the Body

LOCK AND KEY MODEL

hormones or neurotransmitters (the"key") affect target cells by binding to specific receptors (the "lock”), which are often located in the cell membrane

"unlocks" the cell's response. Effect of hormone

AGONIST

“A chemical messenger that binds to a receptor and triggers the cell’s response

often refers to a drug that mimics a normal messenger’s action”.

PILOCARPINE - muscarinic receptor agonist,

bind to and activate muscarinic receptors

Drug Receptor Interactions

Agonist Receptor

Agonist-Receptor

Interaction

Lock and key mechanism

ANTAGONIST

“A molecule that competes for a receptor with a chemical messenger normally present in the

body. The antagonist binds to the receptor but does not trigger the cell’s response”

Atropine - muscarinic receptor antagonist , can bind to muscarinic receptors but it does not trigger the cell’s response.

Antagonist Receptor

Antagonist-Receptor

ComplexDENIED!

CompetitiveInhibition

Drug Receptor Interactions

Definition

“A path by which a

drug, fluid, poison, or other substance is

brought into contact with the body.”

Routes & Targetso Drug delivery intended to

local effect.• Eye, ear, nose

o Drug delivery intended to systemic effect• Circulatory system

Routes of Administration

o2 classes of routes of administration.

1)Enteral2)Parenteral

Factors Deciding Choice of Routeo Type of desired effect, systemic or local.

o Physiochemical properties, solid or insoluble.

o Rapidity of effect.o Dosage form available.o Patient’s age.o Patient’s condition.

Enteral Routes“Drug placed directly in the GI tract”o Most common, economical, and safest.

o Most unreliable and slow.• Sublingual • Buccal • Oral• Rectal

Oral Routeo p.o. or PO o Most conventionalo Economicalo safeo self administered o acceptable to patiento Patient’s Feasibilityo Painless

AdvantagesOvercome by antidotes or emesis

unconscious patients via NG tube (nasogastric)

Disadvantageso Stomach acid inactivation.o First Pass effecto Drug interactiono Food interactiono Absorption slow or irregularo Poorly or erratically absorbed drug

o Esophageal ulcerationo Unconsciouso Precision o Very high doseo Rapid administration

Factors affecting Drug Absorption Orally

o Form of drugo Foodo Digestive transito Drug interaction in digestive tract

Form of drugo Drops or Tablets not have same kinetics

o Sustained-release delays and extends its absorption.

Foodo When should a drug be taken: under

fasting conditions, before, during, after meals?

o consider Pharmacokinetic and Pharmacodynamic parameters.

o Bioavailability when taken during meals;o reduced: tetracyclines, isoniazid, penicillamine, captopril.

o unchanged or little modified: amoxicillin.o increased: propranolol

Food

An hypoglycemic drug before meals.

A gastric protectant taken apart from meals and in the evening at bedtime.

NSAIDs during meals

Digestive Transit

Drug Interactions in the Digestive Tract

o Metals i.e. Fe++, Al ++ form organometallic complexes with antibiotics.

o Activated charcoal

Sublingual / Buccal“held in the mouth or cheeks or under

the tongue.”o SLo SL - Rapid absorptiono Buccal – slower absorptiono Drug stabilityo Clinically useful drugs in sublingual :

• Nitroglycerine• Isosorbide dinitrate• GTN• Clonidine• Methyl testosterone

Sublingual Route Of Administration

BUCCAL DRUG ROUTE

Advantageso Avoid first-pass effecto Low incidence of infectionDisadvantages

inconvenient small doses unpleasant taste of some drugs Erratic absorption.

Rectal Routeo in recurrent vomiting or unconscious

o bypass livero Absorption incomplete, erratico glycerine, diclofenac o Enema & suppository

Advantageso Bypass liver 50%o For childreno In emesis

Disadvantageso Inconvenient & embarrassingo Rectal inflammation occurs

Parenteral Routeo For poorly absorbed drugso For unstable drugso Unconscious patientso Irreversible routeo Cause pain, fear, infection.o must be sterile and little irritant.

Parenteral Routeo Intravenouso Intramuscularo Intradermalo Subcutaneous

Intravenous Route “Placing a drug directly into the

blood stream”o IV o Precision of dose quickly.o Prompt effectso Absorption phase is bypassedo 100% bioavailabilityo precise, accurate and almost immediate

onset of action, o fairly pain free

Intravenous routeo well-controlled throughout the body.

o for irritating solutionso single dose or by continuous infusion.

Disadvantageso Greater risk of adverse effects a. high concentration attained rapidly b. Embolism

c. Hemolysiso Lack of sterilityo IV more difficult In obese person.o Oily solutions & insoluble substances

not suitableo Cant be withdrawn

Intramuscular Route“injection of liquid into the area of

greatest mass of a large muscle”

o more rapid absorption than SC o only 5 IM sites

a. deltoid b. vastus lateralis c. rectus femorisd. ventrogluteal e. dorsogluteal

Intramuscular Routeo IMo Aqueous Solution or specialized Depot

Preparationso contra-indicated anticoagulant therapy.o Rapid effect aqueous solutiono Slow, sustained effect depot preparationo Moderate volume, oily vehicles, irritant, o Absorption rate of blood flow to the

injection siteDisadvantageso Pain, Abscess

Subcutaneous Route

“injection into the fatty layer of tissue just below the dermis of the skin but above the

muscle layer” o SQ, SC, subQ, s.c.o Absorption slow, sustainedo Rapid effect aqueous solutiono For insoluble suspension & solid pellet implantationso Only nonirritant drugs. o over weeks or months,e.g Testosterone , Insulino adrenaline, heparin, vaccines inj. SC

Disadvantageso Not suitable for large volume

o Not for irritant drugso Pain, necrosis, tissue sloughing

Subcutaneous Route

Intradermal Route“Drug injects into layers of

skin”o Multiple puncture of epidermiso BCG, Small pox vaccinationo Testing drug sensitivity-

Penicillin's o Mantoux test for TB

Intrathecal Route

“A needle is inserted between two vertebrae in the lower spine and into the space around the spinal cord.”

o Local routeo Rapid effectso local & Spinal anesthesia o BBB & Blood CSF Barrier o Drug entry into CNS o Acute CNS infections & brain tumors

Disadvantageso infection at site.o Require skilled personel.

Other Routes

o Topicalo Transdermalo Inhalation

Topical Application.

o More conveniento Localized effect on skin lesionso Conjunctiva, nasopharynx, oropharynx, vagina,

urethra, urinary bladder, ear, nose, anal canal for local effects.

o Absorption rapid.

Topical

Disadvantage & Toxicity

o Local irritationo Timolol eye drops contraindicated bronchial asthma and COPD

Transdermal Route“Applied to the skin via physical delivery through a porous

membrane.”o More conveniento Sustained therapeutic blood levels via stratum corneumo Alcohol enhances penetration o Improved complianceo Patch delivers drug at constant rate o Single patch 7 dayso GTN, nictotine, fentanyl, hyoscine, clonidine

Disadvantages

o Local irritation & erythema

o expensive

Vaginal Route“Administered vaginally to women

as a solution, tablet, cream, gel, suppository, or ring. “

o Slow absorptiono Estrogen at menopauseo Prevent thinning of the vaginal wall.

Intranasal Route“Administration of drugs directly

into nose”o either local or systemic effecto nasal decongestants

o Desmopressino Cocaineo Peptide hormone for osteoporosis

Advantages 

o Fast effect o Prevent drug degradation.

Disadvantageso limited volume for administration.

o Drugs for continuous and frequent administration less suitable

o Nasal mucosa irritation.

Inhalation Route“Inhaling of a drug in gas or liquid form; drug is

absorbed through alveoli of the lungs” o Atomized into smaller particles.o Smaller droplets go deeper drug absorption. o for systemic effects

o medical gases and general anesthetics by inhalation.

o Oxygen, nitric oxide and nitrous oxide.

o for local treatmento bronchial indications o partial absorption and general effects.o Antibiotics, mucolytic, beta-adrenergic mimetic,

muscarinic receptor antagonists.

Disadvantageo Oral thrush

o Sore throat

American Drug Laws and Amendments

1938 Food, Drug and Cosmetic Act required proof of safety, authorized factory inspections, established penalties for fraudulent claims.

1952 Durham-Humphrey Amendment designated drugs that must be prescribed by a physician and dispensed by a pharmacist (e.g., controlled substances, etc.)

American Drug Laws cont.

1970 Comprehensive Drug Abuse Prevention and Control Act; Title II, Controlled Substances Act.

Categorized according to potential for abuse.

Regulated distribution of narcotics and other drugs of abuse

Categories of Controlled Substances

Schedule I—not approved for medical use and have high abuse potentials; LSD, heroin, peyote, ecstasy

Schedule II—used medically. High abuse potential (methadone, meperidine, cocaine)

Categories of Controlled Substances

Schedule III - less potential for abuse than I and II but may lead to psychological or physical dependence (Tylenol with codeine)

Schedule IV - some potential for abuse (Valium)

Schedule V - contain moderate amounts of controlled substances.

(atropine and diphenoxylate)

Drug administration cardinal rules Wash hands before giving meds Read MAR carefully. If ever in doubt,

check the original order Never give medications you are

uncertain of unless you have looked them up or have consulted with pharmacy

Drug Administration Cardinal Rules

Never give more than 3cc per IM injection Wear gloves with all injections For sub q injections, use 25G, 5/8” needles Do not give oral meds if patient is

vomiting, sedated, NPO or is unconscious Follow narcotic protocol for signing out of

narcotics

QUESTIONS???

Referenceso Text book of pharmacology for nurses – J.K Grover – Monica malik

o Lippincott illustrated review of Pharmacology

o Katzung. B. G. Basic and clinical Pharmacology

o J.D tripathy, Essential of Medical Pharmacology

o www.Google.com

THANK YOU