Chapter 4 | Introduction to Clinical Pharmacology Flashcards
Anatomy
The study of the basic structures of the body
Physiology
The study of how those body structures function
Clinical pharmacology
The study of the effects and movement of drugs in the human body
More than 3 billion prescriptions are dispensed each year in the U.S.
True
About one half of all Americans take 1 prescription drug regularly and one out of six persons takes at least 3 prescription drugs
True
The Babylonians recorded the earliest surviving prescriptions on clay tablets in 3000 b.c.; Chinese recorded the Pen Tsao (Great Herbal), a 40 volume compendium of plant remedies dating to 2700 b.c.; the Egyptians followed in 1500 b.c. by archiving their remedies on a document known as the Eber’s Papyrus
True
The first recorded reference to the word pharmacology was found in a text entitled “Pharmacology sen Manudictio and Material Medicum” by Samuel Dale, in 1693; before this date, the study of herbal remedies was called “Materia Medica”
True
Friedrich Serturner
first isolated morphine from opium in 1805
Pharmacology as a distinct discipline was officially recognized when the first department of pharmacology was established in Estonia in 1847
True
John Jacob Abel
the father of American pharmacology, founded the first pharmacology department in the US at the University of Michigan in 1890
Pharmacodynamics
The study of the biochemical and physiological effects of drugs and their mechanisms of action. Drug dynamics described their therapeutic effects of drugs, their side effects, their sites of actions.
A drug’s effects on the body may be influenced by many factors, such as:
a person’s age and genetic makeup and disorders the person has other than the one being treated
Pharmacokinetics
Pharmacokinetics: Study of how a drug is processed by the body, with emphasis on the time required for absorption, duration of action, distribution, and method of excretion, i.e. the study of how the body affects drugs.
Drug distribution and elimination
Drug delivery systems, route of administration, modes of excretion.
Every drug has at least three names
-chemical name
-generic (nonproprietary or official) name
-trade (proprietary or brand) name
Chemical name
describes the atomic or molecular structure of the drug.
Generic name
usually have the same ending
Trade name
is chosen by the pharmaceutical company that manufactures or distributes the drug
Drugs are classified by:
therapeutic group; by what disorder or symptom they are used to treat.
(drugs to treat high blood pressure are called antihypertensives; drugs used to treat nausea are called antiemetic drugs (emesis is the technical term for vomiting)
Primary role of a pharma sale rep is to educate and detail physicians so that prescribed medications are delivered in a safe manner and their responsibilities include knowledge and understanding of the following:
- Why your drug should be ordered
- Name (generic and trade) and drug classification
- Intended or proposed use of your drugs
- Effects on the body of your pharmacology product
- Contraindications
- Special considerations (how age, weight, body fat distribution, and individual pathophysiological state affect pharmacotherapeutic response
- Potential side effects
- Why the medication has been prescribed for a particular patient
How the medication is to be administered, including dosage ranges
Anaphylaxis
a severe type of allergic reaction that involves the massive, systemic release of histamine and other chemical mediators of inflammation that can lead to life threatening shock
Allergic and anaphylactic reactions are particularly serious side effects that must be carefully monitored and prevented.
True
Pharmacokinetic and pharmacodynamic concerns including:
adverse drug reactions, contraindications, drug-food interactions, and drug-drug interaction issues
A drug is any substance that produces a physical or psychological change in the body. This definition includes products that are considered medicines (aspirin/antibiotics), products contained in foods (caffeine), and products delivered through other means (nicotine/fluoride)
True
Under the FFDCA (Federal Food, Drug and Cosmetic Act), a drug is defined as any substance “intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease” or a substance other than food “intended to affect the structure or function of the body.”
True
Therapeutics is the branch of medicine concerned with the prevention of disease and treatment of suffering.
True
Pharmacotherapy or pharmacotherapeutics is:
the application of drugs for the purpose of disease prevention and the treatment of suffering.
Substances applied for therapeutic purposes fall into one of the following categories:
-Drugs or medications
-Biologics
-Complementary and alternative medicine therapies
Drugs or medications
A drug is a chemical agent capable of producing biologic responses within the body; desirable (therapeutic) or undesirable (adverse). After a drug is administered, it is called a medication.
Biologics
Agents naturally produced in animal cells, by microorganisms, or by the body itself (hormones, monoclonal antibodies, natural blood products and components, interferons, and vaccines)
Complementary and alternative medicine (CAM) therapies:
These involve natural plant extracts, herbs, vitamins, minerals, dietary supplements; herbal and alternative therapies.
Definition of the cell
The basic structural and functional units of the body and all living organisms
Parts of the cell
-cell membrane
-cell membrane receptors
-nucleus
-cytoplasm/protoplasm
-extracellular fluid
-tissues
-organs
-muscle tissues
-plasma
The Body’s Major Systems:
Cardiovascular
Respiratory
Gastrointestinal
Nervous
Musculoskeletal
Reproductive
Immune
Classes of Nutrients:
proteins
fats
carbohydrates
vitamins
minerals
Cell membrane
All cells are wrapped in semi-permeable membrane that protects them from outside elements and distinguishes them from their surroundings
The nucleus
The brain of the cell that regulates all activities
Muscle tissues:
Skeletal
Smooth
Cardiac
Plasma
the liquid portion of the blood that carries proteins and other substances
Proteins
made up of chains of amino acids
Fats
Stored in special body tissues as a great source of reserve energy
Carbohydrates
The body’s immediate source of energy. It is broken down into glucose and used for immediate metabolic reactions
Vitamins
Substances necessary for growth, development, and normal regulation of metabolic processes. Must be taken in from outside of the body
Minerals
Substances necessary for bodily processes such as the balance of body fluids, the formation and maintenance of bones and teeth, and the proper functioning of muscles.
The main minerals:
Calcium
Potassium
Iron
Sodium
Phosphorous
Iodine
Water
Not a nutrient, but necessary for all body functions (fluids, mostly water, make up at least 60% of the body’s weight)
Cardiovascular System
heart
blood vessels
blood
Respiratory System
nasal passages
trachea
diaphragm
lungs
Gastrointestinal System
mouth
esophagus
stomach
liver
pancreas
gallbladder
small & large intestines
Nervous System
central nervous system: brain/spinal cord
peripheral nervous system: electrical signals
Musculoskeletal System
muscles
bones
other minor systems
Reproductive System
penis
testes
seminal fluid
ovaries
oviducts
uterus
vagina
mammary glands
Immune System
lymph nodes
vessels
cells
Drugs that have a significant potential for abuse are placed into five categories called schedules:
Schedule I drugs have the highest potential for abuse; Schedule V drugs have the lowest potential for abuse.
A teratogen is a substance that has the potential to cause a defect in an unborn child during pregnancy.
Classification of teratogenic risk places drugs into categories A, B, C, D, and X. Category A is the safest group of drugs; Category X poses the most danger to the fetus.
Pharmacokinetics and Pharmacodynamics:
A drug’s formulation is designed to optimize the ability of the body to properly use and then rid itself of the drug.
Pharmacokinetics uses a process called ADME testing to assess the actions of the body on the drug; it measures the rate at which the body absorbs the drug, distributes it to the organs necessary to produce the desired effect, metabolizes it into waste material, and then excretes it from the body.
Therapeutic Window:
The dosage range of a drug that is safe and produces a beneficial result
Absorption
Distribution
Metabolism
Excretion
Drug design and development
-Selectivity: ability to target the intended site
-Affinity: remain attached to the site
-Potency: optimize its strength
-Efficacy: effectiveness
-Safety
What the body does to the drug
drug kinetics
What the drug does to the body
drug dynamics
The Rights of Drug Administration
- Right Patient
- Right Medication
- Right Dose
- Right Route of Administration
- Right Time of Delivery
Right to Refuse Medication
Right to Receive Drug Education
Right Preparation
Right Documentation
Drug Orders and Time Schedules
-STAT: statim; immediately (within 5 mins)
-ASAP: within 30 mins
-Preoperative Order: single order for a drug that is to be given once; PRN pro re nata
Orders not written as STAT/ASAP/NOW/PRN are routine orders within 2 hours
-Standing Order: written in advance of a situation that is to be carried out under specific circumstances.
Teratogen
A teratogen is a substance that has the potential to cause a defect in an unborn child during pregnancy. Classification of teratogenic risk places drugs into categories A, B, C, D, and X. Category A is the safest group of drugs; Category X poses the most danger to the fetus.
Dosages are labeled and dispensed according to:
their weight or volume
The three systems of measurements used in pharmacology:
metric, apothecary, and household.
The difference between the usual effective dose and the dose that induces severe or life threatening side effects
margin of safety
Drugs from laboratory to medicine cabinet
the whole process takes about 10 years
on average, 5 of 4,000 drugs studied in the lab are studied in people; only 1 of 5 drugs studied in people are approved
MAR
medication information system
Routes of Drug Administration: Inhalation
Drugs taken through the lungs by inhaling in aerosol form.
Injection Routes
Administration by injection (parenteral administration); a drug product can be prepared or manufactured in ways to prolong drug absorption from the injection site for hours, days, or longer; do not need to be administered as often as drug products with more rapid absorption
Intramuscular Injection
Drugs given by direct injection into muscle tissues such as the butt, upper arm, or thighs; longer needle because muscle lies below skin and fatty tissue.
Intrathecal Injection
Needle inserted between two vertebrae in the lower spine into the space around the spinal cord
Intravenous or IV
Drugs injected directly into the veins; infusion by gravity or infusion pump; the effect lasts for a shorter time.
Subcutaneous Injection
Needle inserted into fatty tissue just beneath the skin; injected then moves into small blood vessels (capillaries) and is carried away by the bloodstream or reaches the bloodstream through lymphatic vessels. Most protein drugs are used by this method because if taken orally they would be digested in digestive tract.
Oral Administration
Tablets, capsules, and liquids taken by mouth; most convenient and usually safest and least expensive.
Rectal Route
Suppository; drugs mixed with waxy substance that dissolves or liquefies after inserted into rectum; prescribed for people who cannot take drug orally because they have nausea, cannot swallow, or have restrictions on eating
Vaginal Route
Solution, tablet, cream, gel, or suppository that slowly absorbs through vaginal wall.
Sublingual Route
Drugs taken under the tongue; absorbed directly and almost immediately into the blood stream through mucous membranes.
Ocular Route
Drugs taken to treat eye disorders
Nasal Route
Drug breathed in and absorbed through thin mucous membrane that lines the nasal passages; it must be transformed into tiny droplets in air (atomized)
Topical or Cutaneous
Drugs administered through the skin
Transdermal Route
Drugs taken through the skin into the systematic circulation; such as a patch; drug can be delivered slowly and continuously for many hours, days, or even longer. As a result, levels of the drug in the bloodstream can be kept relatively constant.
Examples: nitroglycerin for angina, scopolamine for motion sickness, nicotine for smoking cessation, clonidine for high blood pressure, fentanyl for pain relief.
Medication Errors
First Stage: involves prescribing or ordering medication
Second Stage: when medication is dispensed to patients
Third Stage: when medication is administered and monitored for side effects
*The most common error is dosage; errors also involve antibiotics and analgesics.
Drug Absorption
The movement of a drug into the bloodstream.
Drug absorption affects:
- Absorption affects bioavailability (how quickly and how much of a drug reaches its intended target site of action; or whereby the drug moves from the muscle, digestive tract, or other site of entry into the body toward the circulatory system)
Once absorbed, most drugs do not spread evenly through the body
True
Drug (active ingredient) and additives (inactive ingredient); i.e. tablets are a mixture of drugs, dilutents, stabilizers, disintegrants, and lubricants. The mixture is granulated and compressed into a tablet. The type and amount of additives and the degree of compression affect how quickly the tablet disintegrates and drug is absorbed.
True
Drug products are considered bioequivalent when…
they not only contain the same active ingredients, but also produce virtually the same blood levels over time.
Bioequivalence ensures therapeutic equivalence.
True
enteric
protective coatings for oral drugs that do not harm stomach lining and intended to dissolve in small intestine
Drug Distribution
The movement of a drug to and from the blood and various tissues of the body (fat, muscle, brain tissue). After the drug is absorbed into the bloodstream, it rapidly circulates through the body; the average circulation time of blood is only one minute
Drug Metabolism:
The chemical alteration of a drug by the body. The substances that result from metabolism (metabolites) may be inactive, or they may be similar to or different from the original drug in therapeutic activity or toxicity. Some drugs, called pro-drugs, are administered in an inactive form, which is metabolized into an active form; the resulting metabolites produce the desired therapeutic effects.
Most drugs pass through the liver; the group of P450 enzymes is the liver’s primary mechanism for chemically altering drugs.
Drug Elimination and Excretion:
The last stage of pharmocokinetics. The main route of drug excretion is via the kidneys.
Lungs
Breast Milk
Sweat, tears, urine, feces
Bile
Saliva
Exhaled Air
The kidneys’ ability to excrete drugs also depends on:
urine flow, blood flow through the kidneys, and the condition of the kidneys.
The kidney of an 85 year old person excretes drugs only about half as efficiently as that of a 35 year old person.
Many of the concepts applicable in the study of pharmacology apply equally to unforeseen or inadvertent reactions including adverse drug reactions, adverse effects, drug allergies, drug interactions, and idiosyncratic reactions.
True
Drug Forms
Formulations determine whether a drug acts locally or is absorbed into the systemic circulation. Drug dosage forms are classified according to their physical state (liquid or solid) and chemical composition.
Drug Forms
- Preparations for Oral Use
- Powders
- Pills
- Granules
- Tablets
- Capsules
- Sustained Release
- Enteric Coating
- Caplets
- Gel Caps
- Liquid Drugs
- Syrups
- Solutions
- Elixirs
- Fluid Extracts
- Mixtures and Suspensions
- Tinctures
- Spirits or Essences
- Magmas
- Troches or Lozenges
- Aerosols
- Injectable Drugs
- Topical Drugs
- Liniments
- Semisolid Drugs
- Gels or Jellies
- Emulsion
- Creams
- Lotion
- Ointments
- Plasters
- Transdermal Patches
- Gaseous Drugs (Inhalation Drugs)
- Ophthalmic Drugs
- Otic Drugs
- Nasal Drgus
- Vaginal Drugs
- Rectal Drugs
Dispensing Drugs
OTC over the counter and Rx prescription
Site Selectivity
How do drugs know where to exert their effects? The answer involves how they interact with cells or substances such as enzymes.
Cell Receptors
- A receptor is a molecule with a specific three dimensional structure to which only very specific substances can fit and attach…like a key fits its lock.
- Drugs that target receptors are classified as agonists or antagonists.
- Agonist drugs activate or stimulate their receptors, triggering a response that increases or decreases the cell’s activity.
- Antagonist drugs block the access or attachment of the body’s natural agonists, usually neurotransmitters, to their receptors and thereby prevent or reduce cell responses to agonists.
Enzymes
Instead of receptors, some drugs target enzymes, which regulate the rate of chemical reactions. Drugs that target enzymes are classified as inhibitors or activators (inducers).
Affinity and Intrinsic Activity
A drug’s action is affected by the degree (affinity) between it and its receptor on the cell’s surface and, once it is bound to its receptor, by its ability to produce an effect (intrinsic activity)
Drug receptor complex must be capable of producing an effect in the target area.
Potency and Efficacy
Strength and effectiveness
Drug Response
- Genetic Makeup
- Drug-Drug Interactions
○ Duplication
○ Opposition (Antagonism)
○ Alteration - Dietary Supplement-Drug Interactions
- Drug-Food Interactions
- Drug-Disease Interactions
- Tolerance and Resistance
Adverse Drug Reactions
-Type A (augmented) reaction
-Type B (idiosyncratic) reaction
-Type C (continuing or chronic) reaction
Persist for a long time - corticosteroids can cause adrenal suppression
-Type D (delayed) reaction
Take some time to develop - some neuroleptics can cause tardive dyskinesia
-Type E (end of use) reaction
Risk Factors
-Use of several drugs
-Age (especially in infants / elderly)
-Pregnancy & breast feeding
Young children are at high risk of overdose toxicity
True
Children are less likely than adults to take or be given drugs as directed
True
Ways to encourage compliance with drug treatment
-good communication
-encouraging patient participation
-liking their providers
-using only one pharmacist
-support groups
-memory aids and specially designed medication containers
Results of not complying with drug treatment
it is estimated to result in 125,000 deaths due to cardiovascular disease each year; up to 23% of nursing home admissions, 10% of hospital admissions, etc.
Names of drugs
First, the chemical name
Next, a shorthand version of the chemical name or code name
When a drug is approved by the FDA, it is given a generic (official) name and a trade name (proprietary/brand)
Generic and trade names must be unique to prevent one drug from being mistaken for another when drugs are prescribed; to prevent this possible confusion, the FDA must agree to every proposed trade name.
True
Generic drug development
-generic version is equivalent (within a few percentage points) to original
-appropriate inactive ingredients are used
-the generic version differs from its trade name counterpart in size, color, and shape (a legal requirement)
Legally, bioequivalence of different versions of a drug can vary by up to 20%; however, actual differences are typically only about 3.5% on average and rarely exceed 10% in any single study
True
API
active pharmaceutical ingredient
APIs fall into two basic categories
chemical and biological
The way in which an API works in the body is referred to as its
mechanism of action
Most drugs are either agonists or antagonists
agonists: drugs that attract or bind to cell receptors in order to mimic of enhance endogenous chemical messengers
antagonists: drugs that interfere with destructive or undesirable cell functions
Insulin
agonist: administered to diabetics who no longer produce it in sufficient quantities
Steroids
antagonists: they block cell activities that lead to inflammation
The APT is usually blended with products known as excipients (fillers, dyes, flavors) to create the drug product, which is also known as
the formulation
Excipients are sometimes referred to as
inactive ingredients; they also serve such functions as making a drug more stable, easier to administer, or longer-acting through sustained release of the API
Formulated products are sometimes offered in various strengths and administered using different delivery methods to aid absorption or enhance convenience
True
Strength refers to
the amount of active pharmaceutical ingredient in the drug
Common delivery methods are
-parenteral (intravenous, intra-muscular, subcutaneous)
-rectal (suppository)
-oral (tablet, capsule, liquid)
-transdermal (via skin)
Excipients are the inert ingredients in a drug formulation and serve the following functions:
-making the manufacturing process easier
-enhancing delivery of the active ingredient
-making the product more attractive or recognizable
Excipient Classes
Binders
Fillers
Glidants
Colors
Flavors
Suspending/Dispersing agents
Disintegrants
Lubricants
Compression aids
Sweeteners
Printing inks
Film former/coatings
