Introduction to Pharmacology

Practicum of Health Science Technology 2009 - 2010

What is Pharmacology?

• Pharmaceutical derived from the Greek word for poison

• A science that studies drug effects within a living system

• Deals with all drugs used in society today, legal or illegal, including street, prescription, and non-prescription or over –the-counter medications

Drug

• A drug is defined as any substance used in the diagnosis, cure, treatment, or prevention of a disease or condition

Drug Names

• Chemical Name

• Generic Name

• Trade Name

Chemical Name

• Describes its molecular structure and distinguishes it from other drugs

Generic name

• Determined by the pharmaceutical company along with a special organization known as the U.S. Adopted Names Council (USAN)

Trade Name

• Or brand name- the manufacturer selects alone…can become a registered trademark. They are the only one who can advertise and market the drug under that name

How is the Trade Name Chosen?

• The particular spelling of a brand name drug is proposed by a manufacturer for one of several reasons.

1. To indicate the disease process being treated

• Azmacort- treats asthma

• Rythmol- treats cardiac arrhythmias

2. To simplify the generic name

• Pseudoephedrine to Sudefed

• Haloperidol to Haldol

• Ciprofloxacin to Cipro

3. To indicate the duration

• Slow-K slow release potassium supplement

Prescription Drugs

• Or legend drugs

• Means in order to obtain drug, you must have a legal prescription

Non-Prescription Drugs

• Or Over-the-Counter (OTC) drugs

• Drug that may be purchased without a prescription

Sources of Drugs

Drugs and biological products have been identified or derived from four main sources:

• Plants

• Animals and Humans

• Minerals and Mineral Products

• Synthetic or Chemical Substances Made in the Laboratory

Active Constituents of Plant Drugs

• The leaves, roots, seeds, and other parts of plants may be dried or otherwise processed for use as a medicine and , as such, are known as Crude drugs.

• Their therapeutic effect is produced by the chemical substances they contain.

Active Constituents of Plant Drugs

• When the pharmacologically active parts are separated from the crude preparation, the resulting substances are more potent and usually produce effects more reliably than the crude drug.

Active Constituents of Plant Drugs

• Some of the types of pharmacologically active compounds found in plants, grouped according to their physical and chemical properties, are alkaloids, glycosides, gums and oils

Alkaloids

• Organic compounds that are alkaline in nature and are chemically combined with acids in the laboratory to form water – soluble salts

• Example – Morphine Sulfate

Glycosides

• Active plant substances that, on hydrolysis, yield sugar plus one or more additional active substances

• The sugar is believed to increase the solubility, absorption, permeability, and cellular distribution of the glycoside

• Example - Digoxin

Gums

• Plant exudates • When water is added, some of them will swell and

form gelatinous masses• Others remain unchanged in the GI tract, where

they act as hydrophilic colloids• They absorb water, form watery bulk, and exert a

laxative effect• Are also used to soothe irritated skin and mucous

membranes• Example – Psyllium seeds are a natural laxative

gum• Example – Carboxymethylcellulose are synthetic

colloids

Oils

• Highly viscous liquids and are generally of two kinds

1. Volatile

2. Fixed

Volatile Oil

• Imparts an aroma to a plant

• Because of their pleasant odor and taste, these oils are frequently used as flavoring agents

• Evaporate easily

• Typically non-greasy

• Example – Peppermint

Fixed Oil

• Generally greasy and do not evaporate easily

• Example – Castor Oil

Drug Classification

• Can be approached from two perspectives

1. Clinical Indication

Example – Bronchodilator Drugs

2. Body System

Example – Drugs Affecting the Nervous System

Controlled Substances

• Drugs which are classified according to their use and abuse potential

• Term originated in 1970 as a result of the Controlled Substances Act which was developed to provide increased research into, and prevention of, drug abuse and drug dependence; to provide treatment and rehabilitation of drug abusers and drug dependent persons; and to improve the administration and regulation of the manufacturing, distributing, and dispensing of controlled substances

Schedule of Controlled Substances

• Classifies drugs solely according to their use and abuse potential

• Drugs are classified into numbered levels, or schedules, from Schedule I to Schedule V

• Drugs with the highest abuse potential are placed in Schedule I; those with the lowest potential for abuse are in Schedule V

Investigational Drugs

• The multibillion dollar pharmaceutical industry is constantly screening substances with potential to market as new drugs

• Prospective drugs take anywhere from 5 – 10+ years and huge amounts of money to progress through the Food and Drug Administration required testing sequence

Drug Design

• New drugs are discovered in one of two ways

1. Totally new chemical substance

2. Derived from molecular manipulation of a current drug

Drug Design

• Until recently,designing a new drug by changing the molecular structure of an existing drug was a very slow process of trial and error

Recombinant DNA technologyGene splicing or genetic engineering

• Aided by computer design and use of enzymes, researchers are able to remove DNA chemically from one organism and transplant into other

Testing

• In vitro- in glass

• In vivo- in living

• Many guidelines set by FDA

Animal Phase

• Precedes human testing

• Watching for toxic effects,side effects, addictions, cancerous tumors or fetal deformities

Animal Phase

• Calculating the Therapeutic Index (TI) …. The difference between the dosage that produces a Therapeutic Effect and the dosage that produces a Toxic Effect

Animal Phase

• NOT always a reliable indicator of how well a drug will perform in humans.

Animal Phase

• Modes of Absorption

• Distribution

• Metabolism

• Excretion

Human Testing

• Occurs in three phases

• All participants must be given informed consent

Informed Consent

• Written consent to an experimental procedure by an individual after he or she has been given a careful explanation of the purpose of the study, procedure to be used, the expected effects, and the risks involved

Nuremberg Code

• Developed under the guidance of American physicians as a result of the post World War II trials at Nuremberg of Nazi physicians who had conducted experiments on political prisoners without their consent

The Code states:

• Truly voluntary consent of the human subject is critical

• The experiment must be proved to be valid or made possible only through the use of human subjects

• The results and risks are justified by the study

The Nuremberg Code

• Unnecessary suffering, death, or disability will be avoided

• The experiment will be conducted in a careful and professional manner by scientifically qualified persons

• The subject or the investigator may terminate the experiment at any point that it is felt unendurable or impossible

Human Testing: Phase I

• Healthy volunteers used to study absorption, distribution, metabolism, and routes of elimination or excretion

• Safe dose range, evaluate side effects and establish a correct dosage for therapeutic effect.

• Blood tests, urine analysis, vital signs, and specific monitoring tests are performed during this phase

Human Testing: Phase II

• Drug is administered at gradually increasing dosages to selected individuals with the targeted disease

• During this phase individuals are closely monitored for drug effectiveness and for side effects

• If no serious side effects occur, the study will progress to Phase III

Human Testing: Phase III

• Drug is ready for testing at various different centers in larger numbers than previous phases

• Standard protocols have been established to be followed at each center

Human Testing: Phase III

• Objectives for this phase are:

- Determination of clinical effectiveness

- Drug Safety determination

- Establishment of tolerated dosage or dosage range

Human Testing: Phase III

• Group A

• all patients with the disorder receive the new drug being studied

• results compared to next two groups for side effects and ability to treat disorder

Human Testing: Phase III

• Group B

• all patients have disorder meant to be treated by new drug

• all patients receive a placebo and results are compared to other 2 groups

Human Testing: Phase III

• Group C

• all patients have disorder meant to be treated by new drug

• patients will be treated by another drug currently being used to treat disorder

FDA Approval

• After reviewing all documentation on the safety and effectiveness of the new drug

• May be protected by a patent for up to 17 years

Pregnancy Safe Categories

• Before using any drug during pregnancy, the expected benefits should be considered against the possible risks to the fetus

• The FDA has established a scale to indicate drugs that may have documented problems in animals and/or humans during pregnancy

• For many drugs, this information is unknown

Category A

• Adequate and well – controlled studies indicate no risk to the fetus in the first trimester of pregnancy, and there is no evidence of risk in later trimesters.

Category B

• Animal reproduction studies indicate no risk to the fetus and there are no well – controlled studies in pregnant women

Category C

• Animal reproduction studies have reported adverse effects on the fetus; and there are no well – controlled studies in humans, but potential benefits may indicate use of the drug in pregnant women despite potential risks

Category D

• Positive human fetal risk has been reported in data from investigational or marketing experience, or human studies

• Considering potential benefit versus risk may, in selected cases, warrant the use of these drugs in pregnant women

Category X

• Fetal abnormalities reported and positive evidence of fetal risk in humans is available from animal and/or human studies

• The risks involved outweigh the potential benefits

• These drugs should NOT be used in pregnant women

Medication Orders

• Verbal Order

• Telephone Order

• Incomplete Order

• Incorrect or Inappropriate Order

• Invalid Order

• Orders for Unfamiliar Drugs

Medication Order

Should Include:• Name of patient medication is to be

administered• Medication name• Dosage• Route• Time of administration• Signature of prescriber

Verbal Order

• Given or received verbally

• All orders must be written prior to administration

Telephone Order

• An order given over the telephone

• Prescriber must sign order within 48h of administration

• Person receiving the orders should listen to the order, write it down, then repeat it back to the prescriber completely for verification prior to ending the call

Incomplete Order

• Orders that are not complete in patient name, medication name, dose, route, time, or signature must be clarified and corrected BEFORE administration

Incorrect or Inappropriate Order

• May be judged by the administrator as being incorrect, or inappropriate for the client it is ordered

• It is the administrator’s RIGHT and RESPONSIBILITY to question ANY order or action that is potentially harmful to the patient

• To carry out an order that one knows to be incorrect constitutes negligence

• To change an order by modifying any part of it without the consultation with the prescriber is ILLEGAL

Incorrect or Inappropriate Order

• Validate the order by consulting an authoritative reference source such as a drug reference book

• If the order is apparently incorrect, objectively report the conflicting facts and discuss it with the prescriber

• If the prescriber still wants the medication given as ordered after the objections have been stated the immediate supervisors, or managers should be sought

Incorrect or Inappropriate Order

• If the prescriber decides to administer the medication themselves make sure the documentation reflects the objections and actions that have taken place

Invalid Order

• Orders signed by medical students, unlicensed interns and medical residents; and physicians who do not have prescriptive authority at your institution should not be administered until the order is verified and clarification is made

Order for Unfamiliar Drug

• Prior to administration of an unfamiliar medication, the administrator should “Look It Up” or “Ask the Pharmacists”!

• Administration of an unfamiliar medication while remaining in ignorance of its actions, its intended effects and side effects, and its adverse reactions is considered negligence if it results in harm to the patient

5 Rights of Drug Administration

1. Right Medication

2. Right Patient

3. Right Dosage

4. Right Route

5. Right Time

Medical Terminology

Instructions

Define the following terms in your interactive note book. Utilize KIM technique with the K = Key word/ key term; I = Information/ Definition; and M = Memory Cue – something that will help you to remember the term. Maybe a picture, word, or phrase.

Terms

• Pharmacology• Pharmacopeia• Drug• Chemical Name• Generic Name• Trade Name• Prescription Drug• Non-prescription

Drug

• Alkaloid• Glycoside• Gums• Hydrophilic• Water – soluble• Volatile oil• Fixed oil

Terms

• Controlled Substance

• Therapeutic Index• Therapeutic effect• Informed Consent• Crude drugs

• Toxic effect• Alkaline• Hydrolysis• Distribution• Metabolism• Excretion

Medical Abbreviations

• USAN – United States Adopted Name Council

• OTC – Over – the – Counter• PDR – Physician’s Desk Reference• FDA – Food and Drug Administration• DEA – Drug Enforcement Administration • TI – Therapeutic Index• VO – Verbal order• TO – Telephone order

VIP of the Week

Alexander Fleming

Instructions: Research this person and write the following in your interactive notebook.

• Who is he? Describe him as a person.• What significance did he have to medicine,

science, or health care?• How can you utilize his contribution in

your profession?• How did his contribution affect the world?