PHARMACOLOGY

Generika VS Botika

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A Creative Learning Module

By

Jessica A. Sabas, RN MAN

Professor

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Table of Contents
Foundation of Pharmacology
Definitions
Drug Names
Sources of Drug Standard
Sources of Drug Information
Drug legislation
Basic Pharmacology
Overview
This module will explain the administration of medication with concern for safety and precision
and attention to important physiological factors. However, as the practice of nurses continues to evolve in
this new decade, the demands are expanding beyond the preparation and administration of drugs to
include an increased understanding of drug action at the physiologic level.
In todays practice setting, the nurse must understand the disease process, along with the
assessment needed to establish a solid database from which to analyze and develop nursing diagnosis
relevant to individual care needs. The nurse also must plan and implement patient care in a manner that
involves the patient as an active participants in decisions affecting each individual’s care needs. Therefore
a primary concern throughout is the integration of patient teaching of pharmacology so the patient can
choose an optimal level of health to attain and be provided with the information needed to maximize the
potential of reaching the therapeutic goal. The nurse must provide patient education and verify the degree
of mastery attained to ensure that the individual has the ability to provide safe self-care and monitoring of
the prescribed regimen, including the pharmacologic aspects of care.
Further, by educating the patient regarding the desired therapeutic response of the drug therapy
and explaining the need to contact the physician when this response is not occurring, it allows the patient
to achieve some degree of control over the treatment of the disease process for which the drugs are
prescribed. Meanwhile, as the nurse examines the drug monographs, it becomes apparent what side
effects to drug therapy are to be anticipated. By giving the patient concrete suggestions to alleviate the
bothersome side effects, the possibility of strict adherence to the prescribed regimen is enhanced.
Information on adverse drug effects needs to be taught to the patient in a manner that does not unduly
upset the patient but emphasizes the need for prompt reporting of the adverse effects to the physician
should they occur so the needed modification in the regimen can be made.

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Basic Pharmacology

LEARNING OBJECTIVES

At the end of the module, the students will be able to:

 State the origin and definition of pharmacology

 Explain the meaning of therapeutic methods
 Describe the process used to name the drug
 Differentiate among the chemical, generic, official and brand names of the
medicine
 List legislative acts controlling drug use and abuse
 Differentiate among Schedule I,II,III,IV, and V medications and describe nursing
responsibilities associated with the administration of each types
Basic Pharmacology

Now as you go along, you will understand drugs and how drugs affect the
body system. This module will introduce you to the different drug name and
classifications.
Pharmacology
From Greek word pharmakon means drugs and logos as science. Deals with
the study of drugs and their actions on living organism.
Drugs are chemical substances that have an effect on living organism
Therapeutic drugs, often called medicines, are those drugs used in the prevention or
treatment of diseases. Up until a few decades ago, dried plants were the greatest
source of medicines; thus the word drug was applied to them.
Drugs may be classified according to the body system they affect, for
example, drugs affecting the central nervous system, drugs affecting the
cardiovascular system, or drugs affecting the gastrointestinal system. Drugs may be
classified by their therapeutic use or clinical indications, for example, antacids,
antibiotics, antihypertensives, diuretics or laxatives. Drugs may be classified using the
physiologic or chemical action, for example, anticholinergies, beta- adrenergic
blockers, calcium channel blockers, and cholinergics.
Drugs may be further classified as prescription or non-prescription, also
known as over-the-counter (OTC) drugs. Prescription drugs require an order by a
health professional licensed to describe such as a physician or dentist. Non-
prescription, or OTC, drugs are sold without a prescription in a pharmacy or the drug
section of department or grocery stores. Illegal Drugs, sometimes referred to as
recreational drugs, are drugs or chemical substances used for nontherapeutic purposes.
These substances are obtained illegally or have not received approval for use by the
FDA.

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Basic Pharmacology
DRUG NAMES

Chemical name is the most meaningful to the chemist. By means of the chemical
name, the chemist understands exactly the chemical constitution of the drug and the
exact placing of its atoms, or molecular groupings.

Generic Name (Nonproprietary Names)

Before a drug becomes official, it is given a generic name or common name. A
generic name is simplier than the chemical name. It may be used in any country and
by any manufacturer. It is not capitalized. Students are strongly encouraged to learn
and refer to drugs by their generic name, because formularies are maintained by
generic name. When a therapeutically equivalent drug is available in a generic form, a
generic medicine is routinely substituted for the brand name medicine.
Generic names are provided by the United States Adopted Names (USAN) Council,
an organization sponsored by the U.S. Pharmacopeial Convention, the American
Medical Association, and the American Pharmaceutical Association.

Official name is the name under which the drug is listed by the U.S. Food
Administration (FDA). The FDA is empowered by federal law to name drugs for
human use in the United States.

Trade mark or brand name is followed by the symbol R. This indicates that the
name is registered and that its use is restricted to the owner of the drug, who is usually
the manufacturer of the product. Some drug companies place their official drugs on
the market under trade or proprietary names instead of official names. The trade
names are deliberately made easier to pronounce, spell, and remember. The first letter
of the trade name is capitalized.

Pharmacodynamics is the study of how drugs have effects on the body. The most
common mechanism is by the interaction of the drug with tissue receptors located
either in cell membranes or in the intracellular fluid. The extent of receptor activation,
and the subsequent biological response, is related to the concentration of the
activating drug (the 'agonist'). This relationship is described by the dose–response
curve, which plots the drug dose (or concentration) against its effect. This important
pharmacodynamics relationship can be influenced by patient factors (e.g. age, disease)
and by the presence of other drugs that compete for binding at the same receptor (e.g.
receptor 'antagonists'). Some drugs acting at the same receptor (or tissue) differ in the
magnitude of the biological responses that they can achieve (i.e. their 'efficacy') and
the amount of the drug required to achieve a response (i.e. their 'potency').

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Muscular System

Drug receptors can be classified on the basis of their selective response

to different drugs. Constant exposure of receptors or body systems to drugs
sometimes leads to a reduced response (i.e. 'desensitization') and not in terms of
their maximal response.)

Efficacy: the ability of a drug to produce a maximum response.

Differences in drug efficacy are evaluated by comparing differences in maximal
response at high drug. doses or concentrations. (Example: the drugs in Figure 4
vary only by their efficacy or maximal response, and have the same potency or
EC50 values.)

Pharmacokinetics can be simply described as the study of 'what the body does
to the drug' and includes:
• the rate and extent to which drugs are absorbed into the body and distributed
to the body tissues
• the rate and pathways by which drugs are eliminated from the body by
metabolism and excretion
• the relationship between time and plasma drug concentration.
Absorption is the process by which drug molecules gain access to the
bloodstream from the site of drug administration. The speed of this process (the
rate of drug absorption) and its completeness (the extent of drug absorption)
depend on the route of administration.
Routes of administration can be considered in two categories:
Enteral. Drugs given by mouth are normally swallowed before being absorbed
in the stomach or small bowel, after which they enter the portal venous system
and pass through the liver before gaining access to the systemic circulation.
Some drugs introduced into the alimentary tract are absorbed directly into the
systemic circulation without passing through the liver (e.g. via the buccal,
sublingual or rectal routes), thereby avoiding the potential hazards of gastric
acid, binding to food, and metabolism by gut wall or liver enzymes (first-pass
metabolism).
Parenteral. This includes any route that avoids absorption via the
gastrointestinal tract such as administration by injection, inhalation or by
application to the skin.

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Basic Pharmacology
Absorption after an oral dose is a lengthy process, during which drug
molecules may be damaged (e.g. denatured by gastric acid), sequestered (e.g.
bound to food preventing absorption) or modified by first-pass metabolism.
As a consequence of all these hazards, it is not surprising that absorption is
frequently incomplete following oral administration. The proportion of a dose
that reaches the systemic circulation unscathed is known as the bioavailability
of the drug.
Metabolism is the process by which drugs are chemically changed from a
lipid-soluble form suitable for absorption and distribution to a more water-
soluble form that is suitable for excretion. The process effectively eliminates
the parent drug.
Drug metabolism occurs in two phases:
Phase I – in which drug molecules are altered chemically (by oxidation,
reduction or hydrolysis) to make them suitable for Phase II reactions or for
excretion. Oxidation is much the commonest form of Phase 1 reaction and
involves chiefly members of the cytochrome P450 family of membrane-bound
enzymes in the smooth endoplasmic reticulum of the liver cells. Most products
of Phase 1 metabolism are pharmacologically inactive, although some retain
activity to a greater or lesser degree, while others have activity that the parent
drug did not possess.

Phase II – in which molecules of Phase I metabolite (or in some cases,

unchanged drug) combine with an endogenous substrate to form an inactive
conjugate that is much more water-soluble than the Phase I metabolite. Phase
II reactions include synthesis of glucuronide or sulphate products, acetylation
or methylation, and conjugation with glutathione.
The rate of drug metabolism varies widely between individuals, influenced by
genetic and environmental factors. This is the major reason for inter-
individual differences in the plasma concentration of some drugs after a
standard dose, which leads to wide variation in drug response.
Excretion is the process by which drugs and their metabolites are removed
from the body. They may leave in excreted fluids (chiefly urine and bile),
solids (faeces) or gases (expired air).

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Basic Pharmacology
Excretion is the process by which drugs and their metabolites are removed
from the body. They may leave in excreted fluids (chiefly urine and bile),
solids (faeces) or gases (expired air).
Urinary excretion is the usual route of elimination for low-molecular-weight
drugs that are not metabolised and are sufficiently water-soluble to avoid
reabsorption from the renal tubule. Small water-soluble metabolites that enter
the bloodstream after metabolism in the liver or other organs are also excreted
via this route. Drugs bound to plasma proteins are not filtered by the
glomeruli, but small molecules that are free are filtered and enter the tubules,
where they may be reabsorbed if they are still lipid-soluble, but not if they are
water-soluble.
Faecal excretion is the preferred route of elimination for larger molecular-
weight drugs, including those that are conjugated with glucuronide in the
liver, and any drugs that are not absorbed. Molecules of drug or metabolite
that enter the bile after liver metabolism are carried into the intestinal lumen,
pass down the gut and are eliminated in the faeces. If they are still sufficiently
lipid-soluble, some molecules of unchanged drug or metabolite may be
reabsorbed and re-enter the portal vein. This recycling between the liver, bile,
gut and portal vein is known as the entero-hepatic circulation.
The term distribution refers to the ways in which drugs are transported by the
circulating body fluids to the sites of action (receptors), metabolism and
excretion. Drug distribution is both transport throughout the entire body by the
blood and lymphatic systems and transport from the circulating fluids into and
out of the fluids that bathe the receptor sites. Organs having the most
extensive blood supplies, such as the heart, liver, kidneys and brain, receive
the distributing drug most rapidly. Areas with less extensive blood supplies,
such as the muscle, skin, and fat, receive the drug more slowly.
Half-life
Elimination of drugs occurs by metabolism and excretion. A measure of the
time required for elimination is the half life. The half-life is defined as the
amount of time required for 50% of the drug to be eliminated from the body.
For example, if a patient was given 100 mg of drug that had a half-life of 12
hours, the following would be observed.

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Basic Pharmacology
Time (hrs) Half-life Drug remain in the
body
0 - 100mg 100%
12 1 50mg 50%
24 2 25mg 25%
36 3 12.5mg 12.5%
48 4 6.25mg 6.25%
60 5 3.12mg 3.12%
Note that as each 12 hour period half life passes, the amount remaining is 50%
of what was there 12 hrs earlier. After six half-lives, more than 98% of the
drug is eliminated from the body.
Drug Action
No drug has a single action. When a drug enters a patient a reabsorbed and
distributed, desirable action (expected response) usually occurs. All drugs
however has the potential to affect more than one body system
simultaneously, producing response known as side effects or adverse effects.
When adverse effects are severe, the reaction is known as toxicity. Most of
these side effects are predictable and patients shoukd be monitored so that
dosages can be adjusted to allow the maximum therapeutic benefits with a
minimum side effects.
Two other types of drug action are much more unpredictable. These are
idiosyncratic reactions and allergic reactions.
Idiosyncratic reactions occurs when something unsual or abnormal happens
when a drug is administered . The patient usually shows an overresponse to
the action of the drug. This type of reaction is usually due to a patient’s
inability to metabolize a drug because of a genetic deficiency of certain
enzymes. Fortunately this type of reaction is fairly rare.
Allergic reaction also known as hypersensitivity reaction occurs in about 6-
10% of patients taking medications.This occurs in patients who have
previously been exposed to a drug and have developed antibodies to it from
their immune system
Carcinogenicity is the ability of the drug to induce living cells to mutate and
become cancerous. Many drugs have this potential, so all drugs are tested in
animals species before human investigation to help eliminate this potential. A
drug that induces birth defects is known as teratogens.

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Basic Pharmacology
Variable Factors Influencing Drug Action
Many times, patients state, “That drug really knocked me out!” or “That drug
didn’t touch the pain!” The effects of drugs are unexpectedly potent in some
patients, whereas other patients show little response to the same dose. In
addition, some patients react differently to the same dose of a drug
administered at different times.
Age
Infants and the very elderly tend to be the most sensitive to the response of
drugs. There are important differences in the absorption, distribution,
metabolism, and excretion of drugs in premature neonates, full-term newborns,
and older children. The aging process brings about changes in body
composition and organ function that can affect elderly patient’s response to
drug therapy.
Body Weight
Considerably overweight patients usually require an increase in dosage to
attain the same therapeutic response. Conversely, patients who are underweight
(compared with the general composition) tend to require lower doses for the
same therapeutic response. Most pediatric doses are calculated by milligrams
of drug per kilogram of body weight to adjust for growth rate .
Metabolic Rate
Patients with a higher metabolic rate tend to metabolize drugs more rapidly,
thus requiring either larger does or more frequent administration. The converse
is true for those with lower metabolism of some drugs, thus requiring higher
doses to be administered more often for a therapeutic effect.
Illness
Pathologic condition may alter the rate of absorption, distribution, and
excretion. For example, patients in shock have reduced peripheral vascular
circulation and will absorb IM- or SC- injected drugs slowly; patients who are
vomiting may not be able to retain a medication in the stomach long enough for
dissolution and absorption; patients with diseases such as nephrotic syndrome
or malnutrition may have reduced amounts of serum proteins in the blood
necessary for adequate distribution of drugs; patients with kidney failure must
have significant reduction in the dosages of those medications that are excreted
by the kidneys.

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Basic Pharmacology
Psychological Aspects
Attitudes and expectations play a major role in a patient’s response to therapy
and the willingness to take the medication as prescribed. Patients with diseases that
have relatively rapid consequences if therapy is ignored, such as insulin-dependent
diabetes, usually have a good rate of compliance. Patients with “silent” illness, such
as hypertension, tend to be much less compliant with the treatment regimen.
Another psychologic consideration is the “placebo effect,” A placebo is a drug
dosage form such as tablet or capsule that has no active pharmacologic activity
because the dosage form has no active ingredients.
Tolerance
Tolerance occurs when a person begins to require higher doses to produce the
same effects that lower doses once provided. An example is the person who is
addicted to heroin. After few weeks of use, larger doses are required to provide the
same “high”. Tolerance can be caused by psychologic dependence, or the body may
metabolize a particular drug more rapidly than before, causing the effects of the drug
to diminish more rapidly.
Dependence
Drug dependence, also known as addiction or habituation, occurs when a
person is unable to control the ingestion of drugs. The dependence may be physical,
in which the person develops withdrawal symptoms if the drug is withdrawn for a
certain period; or psychologic, in which the patient is emotionally attached to the
drug.
Cumulative Effect
A drug may accumulate in the body if the next doses are administered before
previously administered doses have been metabolized or excreted. Excessive drug
accumulation may result in drug toxicity.

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Basic Pharmacology
Drug Legislation
Drug legislation protects the consumer and patient. The need for such protection is
great because manufacturers and advertising agents may make unfounded claims
about the benefits of their products.
Federal Food, Drug, and Cosmetic Act, June 25, 1938 (Amended 1952, 1962)
The Federal Food, Dug, and Cosmetic Act of 1938 authorizes the FDA of the
Department of Health and Human Services to determine the safety of drugs before
marketing and to assure that certain labeling specifications and standards in
advertising are met in the marketing of products. Manufacturers are required to
submit new drug applications to the FDA for review of safety studies before product
can be released for sale.
The Durham-Humphrey Amendment in 1952 tightened control by restricting the
refilling of prescriptions. The Kefauver-Harris Drug Amendment in 1962 was
brought about by the thalidomide tragedy. Thalidomide was an incompletely tested
drug approved for use as a sedative-hypnotic during pregnancy. Infants exposed to
thalidomide were born with serious birth defects. This amendment provides greater
control and surveillance of the distribution and clinical testing of investigational
drugs and requires that a product be proven both safe and effective before release for
sale.
Controlled Substances Act, 1970
The comprehensive Drug Abuse Prevention and Control Act was passed by
Congress in 1970. This statute, commonly referred to as the Controlled Substance
Act, repealed almost 50 other laws written since 1914 that related to the control of
drugs. The new composite law is designed to improve the administration and
regulation of manufacturing, distributing, and dispensing of drugs found necessary
to be controlled.
The Drug Enforcement Administration (DEA) was organized to enforce the
Controlled Substances Act, gather intelligence, and train and conduct research in the
area of dangerous drugs and drug abuse. The DEA is a bureau of the Department of
Justice. The director of the DEA reports to the Attorney General of the United
States.
The basic structure of the Controlled Substances Act consists of five classifications
or schedules of controlled substances. The degree of control, the conditions of record
keeping, the particular order forms required, and other regulations depend on these
classifications. The five schedules, their criteria, and the examples of drugs in each
schedule are listed below:

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Basic Pharmacology
Schedule I C Drugs
1. A high potential for abuse.
2. No currently accepted medical use in the United States.
3. A lack of accepted safety for use under medical supervision.
Schedule II C Drugs
1. A high potential for abuse.
2. A currently accepted medical use in the United States.
3. An abuse potential that may lead to severe psychologic or physical dependence.
Schedule III C Drugs
1. A high potential for abuse, but less so than drugs in schedules I and II
2. A currently accepted medical use in the United States
3. An abuse potential that may lead to moderate or low physical dependence or high
psychologic dependence.
Schedule IV C Drugs
1. A low potential for abuse, compared with those in schedule III
2. A currently accepted medical use in the United States.
3. An abuse potential that may lead to limited physical or psychologic dependence,
compared with drugs in schedule III
Schedule V C Drugs
1. A low potential for abuse, compared with those in schedule IV
2. A currently accepted medical use in the United States.
3. An abuse potential of limited physical or psychologic dependence liability,
compared with drugs in schedule IV. Because abuse potential is low, a prescription
may not be required.
The U.S. Attorney General, after public hearings, has authority to reschedule a drug,
bring an unscheduled drug under control, or remove controls on scheduled drugs.
Every manufacturer, physician, dentist, pharmacy, and hospital that manufacturers,
prescribes, or dispense any of the drugs listed in the five schedules must register
biannually with the DEA.

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Basic Pharmacology
A physician’s prescription for substances named in this law must contain the
physician’s name, address, DEA registration number and signature, the patient’s
name and address, and the date of issue. The pharmacist cannot refill such
prescriptions without the approval of the physician. All controlled substances
for ward stock must be ordered on special hospital forms that are used to help
maintain inventory and dispersion control records of the scheduled drugs. When
a nurse administers a schedule II drug, under a physician’s order, the following
information must be entered on the controlled substances record: name of the
patient, date and time of administration, drug administered, and drug dosage and
time.
Possession of Controlled Substances
Federal and state laws make the possession of controlled substances a crime,
except in specifically exempted cases. The law makes no distribution between
professional and practical nurses in regard to possession of controlled drugs.
Nurse may give controlled substances only under the direction of a physician or
dentist who has been licensed to prescribe or dispense these agents. Nurses may
not have controlled substances in their possession unless they are giving them to
a patient under the doctor’s order, the nurse is a patient for whom a doctor has
prescribed scheduled drugs, or the nurse is the official custodian of a limited
supply of controlled substances on a ward or department of the hospital.
Controlled substances ordered but not used for patients must be returned to the
source from which they were obtained (doctor or pharmacy). Violations or
failure to comply with the Controlled Substances Act is punishable by fine,
imprisonment, or both.
Drug Legislation (Canada)
Food and Drugs Act 1927; the Food and Drug Regulations 1953 and 1954,
Revised 1979 and Periodic Amendments.
The Food and Drug Act and the Food and Drug Regulations empower the
Department of National Health and Welfare of Canada to protect the public
from foreseeable risks relating to the manufacture and sale of drugs. The
administration of this legislation is carried out by the Health Protection branch.
It provides for a review of the safety and efficacy of drugsbefore their clearance
of marketing in Canada either prescription or non-prescription products. Also
included in this legislation are requirements for good manufacturing practices,
adequate labeling and fair advertising. Drugs requiring a prescription, except for
narcotics, are listed on Schedule For Schedule G of the Food and Drug
Regulations.

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Muscular System
Requirements for the legitimate administration of drugs to patients by nurses are
generally similar in Canada and the United States. Individual hospital policy determines
specific record-keeping requirements based on federal and provincial laws. Violations
of these laws would be expected to result in fines or imprisonment in addition to the loss
of professional license.
Nonprescription Drugs
In Canada, the Health Protection Branch acknowledges two classes of nonprescription
drugs. A provision is made in Division 10 of the Food and Drug Regulations for
“proprietary medicines” that can be adequately labeled by manufacturers for direct use
by consumers. Laws in each of the 10 provinces determine the actual conditions of
distribution of nonprescription drugs. Proprietary medicines can generally be sold
through any retail outlet, whereas other nonprescription drugs in some provinces may be
sold only in pharmacies. In fact, a few provinces require the direct of a pharmacist in the
sale of certain nonprescription drugs. Most hospitals do not differentiate between
prescription and nonprescription drugs, requiring physician’s orders for both.
Effectiveness of Drug Legislation
The effectiveness of drug legislation depends on the internet and determination used to
enforce these laws, the appropriate by government of adequate funds for enforcement,
the vigor used by proper authorities in enforcement, the interest and cooperation of
professional people and the public, and the education of the public concerning the
dangers of unwise and indiscriminate use of drugs in general. Many organizations help
in this education, including the National Coordinating Council on Patient Information
and Education; the American Medical Association; the American Pharmaceutical
Association; the American Society of Health-System Pharmacists; and local, state, and
county health departments.

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 PRACTICE TEST
Answer the following by encircling the letter of the correct answer. Strictly no
erasure.

When two drugs with similar actions are taken for a double effect is called?
a. Synergistic effect
b. Antagonistic effect
c. Additive effect
d. Displacement

One drug interferes with the action of another is

a. Synergistic effect
b. Antagonistic effect
c. Additive effect
d. Displacement

The combined effect of two drugs is greater than the sum of the effect of each drug
given alone.
a. Synergistic effect
b. Antagonistic effect
c. Additive effect
d. Displacement

The second drug increases the activity of the first drug is

a. Synergistic effect
b. Antagonistic effect
c. Additive effect
d. Displacement

One drug inhibit the metabolism of excretion of a second drug, causing increased
activity of the second drug is
a. Synergistic effect
b. Interference
c. Incompatibility
d. Displacement

this cause deterioration when the two drugs are mixed in the same syringe or solution
a. Synergistic effect
b. Interference
c. Incompatibility
d. Displacement

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 PRACTICE TEST
Essay:
1. Differentiate idiosyncratic reaction to allergic reaction:
2. Explain the factors that cause variations in absorption, distribution, metabolism and
excretion of drugs.
3. What are the sources of patient information?

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REFERENCES

Clayton, B. Stock, Y. (2017). Basic Pharmacology for Nurses. Mosby London.

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