chapter 3 · • nuclear medicine uses isotopes for imaging organ function and biochemistry. •...

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Chapter 3

Pharmacology in Practice


What Is a Drug?

• Alters the body’s biochemical functions and physiological processes

• Exerts a therapeutic effect • A drug can be

– Prescribed by a physician – An OTC product – A homeopathic remedy – A diet supplement


Terms to Remember

drug any substance taken into or applied to the body for the purpose of altering the body’s biochemical functions and thus its physiological processes

therapeutic effect the desired pharmacological action of a drug on the body


What Is a Drug?

• Drugs come from many different sources: – Originally compounded by pharmacist – Now highly researched and standardized

in the lab • A drug may contain one or more

active ingredients. • Drugs also contain inert ingredients.


Terms to Remember

active ingredient the biochemically active component of a drug that exerts a desired therapeutic effect


Terms to Remember

inert ingredient an inactive chemical that has little or no physiological effect that is added to one or more active ingredients to improve drug formulations such as fillers, preservatives, colorings, and flavorings; also called inactive ingredient


Drug Discoveries of the 19th and 20th Centuries

• Smallpox—the first vaccination • Radioactive drugs • Insulin—a lifesaver! • Penicillin—the first antibiotic • The scourge of polio • The pill


Smallpox—The First Vaccination

• Dr. Edward Jenner performed the first experimental vaccine in 1796.

• He noticed an immunity from smallpox among dairy workers who had been exposed to cowpox.

• Cowpox exposure produced antibodies that provided cross-immunity with smallpox.


Terms to Remember

antibody the part of the immune system that neutralizes antigens or foreign substances in the body

vaccine a substance introduced into the body in order to produce immunity to disease



Jenner found the disease could also be prevented by inoculating with bacteria from a person with a mild case of smallpox.



• Smallpox was the first disease to be eradicated.

• Early vaccinations had a high complication rate due to problems of purity and mass production.


Radioactive Drugs

• Madame Marie Curie did pioneering work with radioactivity in early 1900s.

• She won two Nobel prizes: – One in physics – One in chemistry

• She promoted the use of radium to relieve suffering of soldiers in World War I.


Radioactive Drugs

Without the discovery of radioactivity, there would be no

– Organ scans – CAT scans – MRI scans – Radiation therapy – Nuclear medicine – Nuclear pharmacy


Insulin—A Lifesaver!

• Sir Frederick Banting and Charles Best discovered insulin in the 1920s.

• Previous research showed a link between the pancreas and diabetes.

• Dogs with diabetes were kept alive with an extract from the pancreas, which was later isolated and purified into insulin.



• Before insulin, people with diabetes suffered complications and early death.

• Insulin is hailed as one of the most significant medical advances of the time.

• It extended the lives of millions of people around the world.



Pharmacy techs help diabetic patients lead near-normal lives by

– Helping them select diabetic supplies

– Stressing the importance of insulin dosing and blood sugar monitoring


Terms to Remember

antibiotic a chemical substance that is used in the treatment of bacterial infectious diseases and has the ability to either kill or inhibit the growth of certain harmful microorganisms


Penicillin—The First Antibiotic

• Discovered by accident in 1928 by researcher Dr. Alexander Fleming

• Noticed that his bacterial cultures were contaminated with a fungus and that the fungus prevented the bacteria from growing

• Isolated and identified the antibacterial fungus Penicillium



• Penicillin saved many soldiers’ lives in World War II.

• It wasn’t mass produced until 1945.

• It causes the most drug allergies and underscores the need to check drug allergy histories.

Safety Note



Patients need to complete the full course of any antibiotic treatment in order to avoid developing a resistance to the antibiotic.


The Scourge of Polio

• Polio is a virus that attacks the central nervous system.

• It affected mostly children, causing paralysis or death.

• In 1952 over 21,000 cases of the most severe form, paralytic polio, were reported in the US.


The Scourge of Polio

• Jonas Salk and Albert Sabin independently invented polio vaccines.

• In 1953 Salk developed an injectable vaccine containing killed viruses.

• Mass vaccines began in 1955, when there were 28,000 cases reported.

• In 1956 there were only 15 reported cases.


Drug Classification

• Legend or prescription drugs • OTC drugs • Homeopathic medications • Diet supplements


Terms to Remember

legend drug a drug that requires a prescription from a licensed provider for a valid medical purpose


Legend or Prescription Drugs

• Can be dispensed by prescription only

• May be available as a – Trade name – Branded product – Generic

• Pharmacy tech must have working knowledge of the name of the 200 most common drugs



• Can be controlled or noncontrolled • Drugs with potential for abuse are

controlled • Misuse of medications can result in

– Drug tolerance – Psychological dependence – Physical dependence – Addiction


Terms to Remember

drug tolerance a situation that occurs when the body requires higher doses of a drug to produce the same therapeutic effect

psychological dependence taking a drug on a regular basis because it produces a sense of well-being; if the drug is stopped suddenly, anxiety withdrawal symptoms can result


Terms to Remember physical dependence

taking a drug continuously such that physical withdrawal symptoms like restlessness, anxiety, insomnia, diarrhea, vomiting, and “goose bumps” occur if not taken

addiction compulsive and uncontrollable use of controlled substances, especially narcotics



• Major role of the pharmacy profession is to protect the public.

• Monitoring prescriptions for controlled drugs is an important part of this role.

• The pharmacy tech must be alert for potential forgeries and must evaluate requests for early refills.


Terms to Remember

over-the-counter (OTC) drug a drug sold without a prescription


OTC Drugs

• OTC drugs can be purchased without a prescription.

• FDA must approve OTC drugs as safe and effective.

• Many OTC drugs started out as prescription drugs: – Advil – Claritin – Zyrtec


OTC Drugs • OTC drugs must have

clear labeling, as they are often purchased without interaction with pharmacist.

• FDA labeling requirement (“Drug Facts” box) allows patients to compare active ingredients.


Terms to Remember

homeopathic medications very small dilutions of natural drugs claimed to stimulate the immune system


Homeopathic Medications

• These medications use subclinical doses of natural extracts or alcohol tinctures.

• The belief is that small doses stimulate the body’s own immune system.

• Most homeopathic medications are OTC, but some are prescription only.


Terms to Remember

diet supplement a category of nonprescription drugs that includes vitamins, minerals, and herbals that are not regulated by the FDA


Diet Supplements

• Available without a prescription

• Not stringently controlled like prescription or OTC drugs

• FDA regulation for patient safety only


Sources of Drugs

• Natural sources • Synthetic, synthesized, and

semisynthetic drugs • Biogenetically engineered drugs


Natural Sources

Drugs can come from natural sources such as

– Single-celled organisms – Plants – Animals – Minerals – Humans


Natural Sources

Where do we get . . . – Streptomycin (antibiotic)

• Streptomyces griseus (bacterium) – Acetylsalicylic acid (aspirin)

• Bark of the white willow tree – Milk of magnesia (antacid and laxative)

• Magnesium oxide – Opium (source of morphine and heroin)

• Poppy plant


Synthetic, Synthesized, and Semisynthetic Drugs

• Many naturally occurring chemicals have been synthesized.

• Synthesized drugs are created in the lab.

• Synthesized drugs imitate naturally occurring drugs (e.g., adrenaline).


Terms to Remember

synthetic drug a drug that is artificially created but in imitation of naturally occurring substances



• Synthetic drugs do not occur in nature.

• Synthetic drugs exert a specific pharmacological effect.

• Barbiturates (used to treat seizures) are an example of synthetic drugs.


Terms to Remember

semisynthetic drug a drug that contains both natural and synthetic components



• Semisynthetic drugs contain both natural and synthetic molecules.

• Semisynthetic penicillins are examples: – Dicloxacillin – Nafcillin

• These derivatives are effective against bacteria that are resistant to natural penicillins.


Biogenetically Engineered Drugs

Biotechnology produces synthetic drugs by combining the sciences of

– Biology – Chemistry – Immunology


Terms to Remember

biotechnology the field of study that combines the sciences of biology, chemistry, and immunology to produce synthetic, unique drugs with specific therapeutic effects


Terms to Remember

deoxyribonucleic acid (DNA) the helixshaped molecule that carries the genetic code


Terms to Remember

genome the entire DNA in an organism, including its genes


Terms to Remember

ribonucleic acid (RNA) an important component of the genetic code that arranges amino acids into proteins

genetic engineering process of utilizing DNA biotechnology to create a variety of drugs


Biogenetically Engineered Drugs

Genetic engineering uses DNA biotechnology to create drugs:

– Insulin for diabetics – Clotting factors for hemophiliacs – Anti-inflammatory drugs for rheumatoid

arthritis – Drugs for combating viral and bacterial

infections


Uses of Drugs

• Therapeutic agents • Pharmacodynamic agents • Diagnostic agents • Prophylactic agents • Destructive agents


Terms to Remember

therapeutic agent a drug that prevents, cures, diagnoses, or relieves symptoms of a disease


Therapeutic Agents

A therapeutic agent helps to maintain health: – Vitamins and minerals to regulate metabolism – Baby aspirin for those at risk for heart attack


Therapeutic Agents

A therapeutic agent helps to relieve symptoms: – Ibuprofen to treat fever or inflammation – Narcotics to prevent severe pain – Diuretics to control excess fluid


Therapeutic Agents

A therapeutic agent helps to combat illness:

– Antibiotics to fight infection – Antiviral medications to delay AIDS

progression


Therapeutic Agents

A therapeutic agent helps to reverse diseases’ processes: –Drugs to control

• Depression • High blood pressure • High cholesterol • Diabetes


Pharmacodynamic Agents

Alters body functioning – Stimulate or relax muscles – Dilate or constrict pupils – Increase or decrease blood sugar – Decongestants for nasal stuffiness – Anesthetics to cause numbness – Oral contraceptives to depress

hormones


Terms to Remember

pharmacodynamic agent a drug that alters body functions in a desired way


Diagnostic Agents

• Chemicals containing radioactive isotopes can be used diagnostically.

• Radioactive isotopes are unstable and give off energy in the form of radiation.

• These can act as tracers inside the body to diagnose and treat illness.


Terms to Remember

radiopharmaceutical a drug containing radioactive ingredients, often used for diagnostic or therapeutic purposes


Diagnostic Agents

• Nuclear medicine uses isotopes for imaging organ function and biochemistry.

• Low doses and short exposure are safe for patients.

• Nuclear pharmacy is a specialization for pharmacists and pharmacy technicians.


Prophylactic Agents

A prophylactic agent prevents illness or disease:

– Antiseptic or germicidal chemicals – Vaccines – Antibiotics, in cases where patient is

highly susceptible to infection


Terms to Remember

prophylactic agent a drug used to prevent disease


Destructive Agents

Destructive agents kill things: – Bacteria – Fungi – Viruses – Cells (normal or cancerous)


Terms to Remember

destructive agent a drug that kills bacteria, fungi, viruses, or even normal or cancer cells

antineoplastic drug a cancer-fighting drug


The Food and Drug Administration (FDA)

• Drug approval process • National Drug Code (NDC) number • Drug information for health

professionals • Drug warning systems • Drug recall process


Drug Approval Process

• Pharmaceutical companies begin with extensive preclinical animal laboratory research.

• When investigational new drugs are approved by the FDA and the company’s IRB, human studies can begin.



• After Phase 3, drug makers can apply for a new drug application (NDA).

• Study results are evaluated by advisory panel.

• If benefits outweigh risks, drug will likely be approved.

• FDA may fast-track some drugs for early approval.



Developing drugs is risky and costly: – Of the 5,000 – 10,000 compounds

• 250 will enter preclinical testing • 5 will enter human clinical trials • 1 will be approved

– Developing a new drug is a 10-year, $1 billion effort.

– Extended patents allow drug companies to recoup these costs.


Terms to Remember

generic drug a drug that contains the same active ingredients as the brand name product and delivers the same amount of medication to the body in the same way and in the same amount of time; a drug that is not protected by a patent



• Once a brand name drug is off patent, generic versions can be produced.

• Generic drug applications are abbreviated: – Do not require preclinical or clinical data – Must instead prove that the generic is

bioequivalent to the brand name drug


Terms to Remember

abbreviated new drug application (aNDA)

the process by which applicants must scientifically demonstrate to the FDA that their generic product is bioequivalent to, or performs in the same way as, the innovator drug


Terms to Remember

bioequivalent a generic drug that delivers approximately the same amount of active ingredient into a healthy volunteer’s bloodstream in the same amount of time as the innovator, or brand name, drug



Pharmaceutically equivalent generics – Contain the same amount of active

ingredient as the brand name drug – Come in the same dosage form – Meet the same standards for

• Strength • Quality • Purity • Identity


Terms to Remember

pharmaceutically equivalent drug product

a drug product that contains the same amount of active ingredient in the same dosage form and meets the same USP–NF compendial standards (i.e., strength, quality, purity, and identity); can be substituted without contacting the prescriber



Pharmaceutical alternative generics – Contain the same active therapeutic

ingredient as the brand name drug – Contain different salts – May be in different dosage forms


Terms to Remember

pharmaceutical alternative drug product

a drug product that contains the same active therapeutic ingredient but contains different salts or different dosage forms; cannot be substituted without prescriber authorization



Generic drugs help control the high cost of pharmaceuticals:

– Dispensing of generics saves 30 to 80% compared to brand name drugs.

– Multiple companies may manufacture generics, thereby fostering competitive pricing.

– Generics save customers over $10 billion each year.


National Drug Code (NDC) Number

Every drug is assigned a unique Nation Drug Code number, made up of

– Labeler code, identifying manufacturer – Product code, identifying drug – Package code, identifying the

packaging size and type


Terms to Remember

National Drug Code (NDC) number a unique number assigned to a brand name, generic, or OTC product to identify the manufacturer, drug, and packaging size


National Drug Code (NDC) Number


Drug Information for Health Professionals

FDA requires manufacturers to provide scientific information to pharmacists in the form of a product package insert.


Terms to Remember

product package insert (PPI) scientific information supplied to the pharmacist and technician by the manufacturer with all prescription drug products; the information must be approved by the FDA


Drug Information for Health Professionals

Product package insert provides information about – Description – Clinical pharmacology – Indications and use – Contraindications – Warnings – Precautions – Adverse reactions – Drug abuse and dependence – Overdose – Dosage and administration – How supplied – Date of the most recent revision of the labeling


Drug Warning Systems

• All drugs have a risk of toxicity. • Adverse drug reactions (ADRs) may not

always be predictable or preventable. • FDA has two central reporting systems

to detect and assess adverse reactions: – MedWatch – Vaccine Adverse Event Reporting System

(VAERS)


Terms to Remember

adverse drug reaction (ADR) a negative consequence to a patient from taking a particular drug



• MedWatch is a clearinghouse for information on – Safety alerts for drugs – Biologics – Diet supplements – Medical devices

• MedWatch is a voluntary program that allows any healthcare professional to report a serious adverse event.


Terms to Remember

MedWatch a voluntary program run by the FDA for reporting serious adverse events, product problems, or medication errors; serves as a clearinghouse to provide information on safety alerts for drugs, biologics, diet supplements, and medical devices including drug recalls



Problems in MedWatch might be addressed by

– Improving prescribing information – Educating healthcare workers or the

public – Changing the product labeling – Recalling the product



Black box warnings may also be communicated through MedGuides, which are designed to

– Inform the patient about the drug – Promote the safe use of the drug – Ensure that patients have access to

information regarding benefits and risks of the drug


Terms to Remember

MedGuide written patient information mandated by the Federal Drug Administration (FDA) for select high-risk drugs; also known as a patient medication guide



The Vaccine Adverse Event Reporting System (VAERS) is operated by FDA and CDC:

– Collects information on adverse events that occur after vaccination

– Has received over 123,000 reports since 1990

– Accepts reports made online, via telephone, and by mail


Terms to Remember

Vaccine Adverse Event Reporting System (VAERS)

a postmarketing surveillance system operated by the FDA and CDC that collects information on adverse events that occur after immunization


Drug Recall Process

• FDA may issue a drug recall when risk outweighs perceived benefit.

• Manufacturer may voluntarily withdraw a drug because of future liability concerns.

• There are three classes of recalls (see Table 3.4).


Drug Recall Process


Terms to Remember

drug recall the process of withdrawing a drug from the market by the FDA or the drug manufacturer for serious adverse effects or other defects in the product


Terms to Remember

black box warning a warning statement required by the FDA indicating a serious or even life-threatening adverse reaction from a drug; the warning statement is on the product package insert (PPI) for the pharmacy staff and in the MedGuide for consumers


Drug References • FDA Online Orange Book provides

information on generic substitution of drugs.

• United States Pharmacopeia describes drug substances and dosage forms.

• National Formulary describes pharmaceutical ingredients.

• See page 77 for other references.


Terms to Remember

FDA Online Orange Book an online reference that provides information on the generic and therapeutic equivalence of drugs that may have many different brand names or generic manufacturer sources

chapter 3 · • nuclear medicine uses isotopes for imaging organ function and biochemistry. •...

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