5/23/2012

What do you think of when you

hear the word “pharmacology”?

Pharmacology

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Delete text and place photo here.After completing this unit, you will be able to describe:-Where drugs come from-Mechanism of action of drugs-How drugs are grouped by classes-Dis/advantages of drug admin.-4 major processes of pharmacokinetics-Conversion between systems-Basic medication dosage calculations

http://www.youtube.com/watch?v=Btqlf6Rs_Ek

Pharmacy:

Originated from the

Greek term

‘Pharmakon’

which means

medicine or drug.

Pharmacology: is the study of drugs

Where do they come from?

1. Natural sources (plants/ animals)

2. Microscopic organisms (bacteria, fungi, molds)

3. Synthetics & Bioengineering

Pharmacology

Sources: NaturalPharmacognosy: study of drugs naturally derived from

plants or animals* Drug Therapy traces back to the earliest recorded history

* Oldest herbal medicine described in Egyptian Papyrus Scroll

-included gargles, suppositories, ointments, and inhalations (all plants)

•We still use some plant and animal derived meds today

•Plants were main source until early 1900s

•1921- Banting & Best extracted insulin from a pancreas and tested it on diabetic dogs in attempt to lower blood sugar (tested on humans in 1922 and became sole source of insulin for 60 years)

•How do you feel about animal testing?

•Downfalls of natural meds: poor absorption, quick breakdown, slow & expensive process, impurities, scarce

DRUGS obtained from plants/animals

Source Drug(s) UsePoppies Codeine &

morphineTo treat pain

Foxglove Digitalis To treat congestive heart failure

Yew Taxol To treat cancer

Thyroid Glands Thyroid Hormone As hormone replacement

Stomachs Pepsin As digestive enzyme

Sources cont…

Delete text and place photo here.Microscopic Organisms:Penicillin- one of the 1st non-plant or animal derived drugs

- produced by a mold- Sir Alexander Fleming isolated Penicillin in 1928

Most of today’s infection fighting drugs are made from microorganisms

Chemists & molecular biologists make all antibiotics this way

Sources cont…

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Synthetics & Bioengineering:- Chemists have resolved many natural medicine problems- Medicinal chemistry: modifies natural products by synthetic production- Injectable meds have modified into forms that can be taken orally, inhaled, topically-Number of doses have decreased-Aspirin, (once extracted from willow bark) is now synthetically produced-Bioengineering has allowed us to produce drugs that were once only available from animals by genetically altering bacteria (1st-insulin)-Until 1980, insulin was taken from pigs/cows (foreign)

-Scientists insert human gene for insulin into bacteria causing insulin production

http://www.youtube.com/watch?v=d9ouk_46xA8

What do you think???

Jack Kevorkian, a medical doctor, is most famous for his support for the individual\'s right to die and assisted suicides. In 1999 Dr. Kevorkian was sentenced to ten to twenty-five years in prison when a jury found him guilty of second-degree murder, delivery of a controlled substance and administering a lethal injection to a terminally ill man. His activities stirred debate and brought the right to die into the spotlight of media attention. Studies indicate that most doctors seem to support a terminally ill patient’s right to end his own life.

http://www.youtube.com/watch?v=YxuTMH7b1VU&feature=relatedhttp://www.youtube.com/watch?v=XDOzT3_HfwI&feature=related

http://www.youtube.com/watch?v=4ghMB4yH6nw&feature=related

Case Study

5/__/2012

How do you feel about the abuse of

pharmaceutical distribution to

patients from medical professionals?

5/29/2012

What do you think can be done to

help decrease the number of patients that become dependant on prescription drugs? Is

this a problem?

Drugs:

Chemicals that affect

the function of living

organisms.

HOW?

They produce their effect

by interacting with other

chemicals in the body

(MOA)

Pharmacotherapeutics:

-Examines the MOA of drugs

-Describes the effects produced by a drug

-Determines what dose of a drug is needed to produce desired effect

-Determines what dose of a drug produces toxic effects

PharmacotherapeuticsPharmacotherapeutics

Mechanisms of Action

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-Drugs w/ same MOA belong to same therapeutic class. - they produce their effects the same way - although same class, each is a different chemical - (Benadryl & Claritin both treat allergies, both in antihistamine therapeutic class but different chemical) - Antihistamines work by BINDING to the same chemical (a protein in the body, a histamine receptor)-Most drugs use 1 of 4 MOAs which all rely on the lock & key principle

-Drug is key, lock is the chemical in body to which the drug binds (usually a protein)

MOAs continued…

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-Four most common MOAs:1.Binding to & stimulating a receptor in body

-Receptors are proteins found in cells which cause a response within a cell when the receptor is stimulated by a naturally occurring key

- Different cell types = different receptors

- Drugs that work according to this MOA imitate the natural key within the body, called agonists or mimetics2.Binding to & Blocking a receptor in body

- some bind with no response other than to prevent the natural key from binding

- drugs that work according to this MOA are called antagonists or blockers

MOAs continued…

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-Four most common MOAs cont:3. Inhibiting an Enzyme

- Enzymes are proteins in the body that speed up chemical reactions

- Two types of enzymes1. Anabolic: play a constructive

role2. Catabolic: play a destructive

role- They increase concentration of

something if they slow its destruction- They decrease concentration if they

slow its production- These drugs are enzyme inhibitors

4. Decreasing the movement of a chemical across a cell membrane

MOAs continued…

-pumps or channels in the cell membrane control movement of chemicals in and out

-pumps can be turned on/off, channels can be opened/closed-Some drugs work by inhibiting specific pumps and others block specific channels

Case Study #2

MOA Demonstration

Divide Class in

5/6/2010

What do you find most confusing about pharmacology so far? What should we refocus on if anything at this point?

5/12/2010

List an example of a common side effect associated with medications. Why do they occur?

Side Effects

- Many drugs produce undesired effects-Any effect produced by a drug that is not the desired effect is known as a side effect

-2 categories: Local & Systemic-Local Side Effects: occur before a drug is absorbed into the bloodstream

-Ex. Aspirin can irritate stomach lining-Ex. Inhalers can cause a dry throat/cough-Ex. Antibiotics can cause diarrhea when they kill naturally occurring bacteria

-Systemic Side Effects: take place after a drug is absorbed into the bloodstream

-Allergic reactions can occur since drugs are not a natural part of the body

Side Effects

-Systemic effects often occur because the drug effects cell other than the target cells.

EX: Bronchodialators produce the desired effect by stimulating epinephrine receptors in the respiratory passages however they also increase the heart rate by stimulating epi receptors in the heart & cause insomnia by stimulating epi receptors in the brain- Side effects will continue to be an issue until science develops a way of delivering drugs only to the desired targets within the body!

Classes:

Drugs in a therapeutic

class produce

their effect in the same

way however

differences between

drugs within a class do

exist.(Benadryl/Claritin)

-One drug in a class may upset one’s stomach while another may cause drowsiness

-Physicians must consider these differences when prescribing a drug

Therapeutic ClassesTherapeutic Classes

Classes

1 Angiotensin Converting Enzyme Inhibitors-Angiotensin is a protein that occurs naturally in the body; also a powerful vasoconstrictor used to regulate BP (narrow vessels increase BP)-Overactive angiotensin causes hypertension-ACE activates angiotensin, therefore if ACE is inhibited or blocked, the amount of angiotensin produced by the body is reduced. -This reduction dilates/widens the blood vessels and lowers BP-ACE inhibitors are a drug class that regulate BP by inhibiting angiotensin converting enzyme-Available only by prescription

5/13/2010 How many of you would be interested in

some extra credit product points on your final exam???? Would you be willing to sign up as a group for Relay for Life?

Would you go to the Ronald McDonald House on a Saturday?

Would you take part in a RMD Walkathon?

ACE inhibitor factsACE inhibitor facts

Representative drugs: Accupril, lotensin, Prinivil, Vasotec, Zestril

Indications: Hypertension (High BP)

Common Side Effects: headache, dizziness

Classes: Beta-1 Blockers

2. Beta-1 Blockers: Naturally released epinephrine (adrenalin)

and norepinephrine are released in low amounts

-release at higher level when startled, frightened, or anxious

-they increase heart rate when they bind to and stimulate beta-1 receptors in the heart

-Beta-1 Blockers bind to beta-1 receptors without stimulating them (blocking epi/nor) and decreasing HR

-EX. Lopressor, Tenormin, Toprol -Indications: hypertension, tachycardia -Common Side effects: dizziness, drowsiness

Classes: Beta-2 AgonistsClasses: Beta-2 Agonists

3. Beta- 2 Agonists: Beta-2 receptors are responsible for the function of smooth muscles that control body functions -control functions that you don’t control -B2A produce same effects in lungs as natural epi by mimicking and stimulating the receptors-oral form- tablets, liquids, inhalers

EX. Ventrolin,Proventil, Serevent, Alupent, BrethineIndications:Asthma, EmphysemaCommon SideEffects:Tremors, Increased HR, insomnia

Classes: Antihistamines

4. Antihistamines: Histamines are released from mast cells when

exposed to allergen - Histamine binds to and stimulates histamine

receptors, causing allergy symptoms (sneezing, watery eyes, runny nose, etc) -Antihistamines bind to receptors but do not

stimulate them- their presence prevents histamine

from binding and reduces the allergic symptoms

EX: Allegra, Benadryl, Claritin, Zyrtec Indications: itching, nasal congestion,

seasonal allergies Common side effects: drowsiness, dry mouth

5/19/2010 (Q of D)

3 questions you could potentially ask

Mr. Kevin Bailey after his presentation

Classes: H2- Antagonists5. H2- Antagonists: Histamines are not only allergy related but

also aid in digestion - food in the stomach triggers its release

which causes secretion of hydrochloric acid - It first binds to and stimulates H2 receptors

in the stomach -too much histamine leads to excess

hydrochloric acid which can cause ulcers and other gastrointestinal disorders

-H2 antagonists bind & block these receptors decreasing the amount of acid after meals

EX. Tagamet, Pepcid, Zantac. Indications: gastroesophageal reflux, ulcersCommon Side Effects: diarrhea, headache

Classes: Proton Pump Inhibitors6. Proton Pump Inhibitors: Parietal cells in the stomach use

proton pumps to move hydrogen ions into cells

– parietal cells use the H ions to produce stomach acid

-proton pump inhibitors turn off the pumps and reduce stomach acid

EX: PrilosecIndications: gastroesophageal reflux,

ulcersCommon Side Effects: diarrhea,

headache

5/21/2010

Why is it not possible to have only one class of drugs or one MOA?

Classes: Narcotic Analgesics7. Narcotic Analgesics:

- Endorphins are natural occurring pain relievers produced by our bodies

-they inhibit nerve cells that carry pain

impulses to our brain when they bind to

and stimulate endorphin receptors in the spine -N.A. bind to and stimulate the same

receptors which reduces pain-most potent pain meds avail/ script only

Representative Drugs: Morphine, codeine, Demerol, Vicodin, Percodan

Indications: severe painCommon Side Effects: Drowsiness, slow &

shallow respirations, constipation

8. Nonsteroidal Anti-inflammatory Drugs:- prostaglandins are chemicals produced in the body that cause pain & swelling associated with inflammation-Ex: prostaglandins produced when an ankle is twisted/sprained

-prostaglandins are made by an enzyme called prostaglandin synthase-NSAIDs inhibit prostaglandin synthase which then reduces the production of prostaglandins, hence less pain(script and non script)-Representative Drugs: aspirin, motrin, advil, relafen, naprosyn, aleve-Indications: mild-mod pain, inflammation, fever-Common side effects: stomach irritation

Classes: Nonsteroidal Anti-inflammatory Drugs

Classes: Reverse Transcriptase Inhibitors

9. Reverse Transcriptase Inhibitors:-The human immunodeficiency virus (HIV) is the virus that causes AIDS

- the virus infects the immune system cells by injecting a cell with a small piece of its ribonucleic acid (RNA)

- RNA builds protein in the body and cells are made of protein

- DNA determines a cells genetic makeup-HIV virus uses its own RNA to reproduce itself in the body (RNA is converted into DNA (deoxyribonucleic acid ) in the cell-The cell then produces thousands of new viruses which then infect thousands of others

Classes: Reverse Transcriptase Inhibitors cont..

A natural enzyme, reverse transcriptase, is needed to convert RNA to DNA.

Reverse transcriptase inhibitors decrease the activity of the enzyme, slowing down the progress of HIV

Representative Drugs: AZT, Combivir, Sustiva, Retrovir

Indications: HIV Infection

Common Side Effects: anemia, fever, rash, headache, lack of energy, nausea, vomiting, diarrhea, stomach pain, cough, shortness of breath, sore throat

Classes: Statins

10.Statins:Liver produces much of body’s cholesterol- For some, a diet change is not sufficient in lowering cholesterol levels

HMG CoA reductase enzyme is needed by the liver to produce cholesterol

Statins (drugs) inhibit HMG CoA r.e., thus reducing the production of cholesterol

(most commonly prescribed drugs in US)Rep Drugs: Lipitor, Pravachol, ZocorIndications: high cholesterol (beyond diet)Common Side Effects: nausea, vomiting,

diarrhea, liver damage

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Routes of administration are the methods used to get a drug into the tissues of the body in order to produce the desired effects

-Two main routes: Oral & parenteral

Oral: most common route-drug is swallowed in the form of a tablet, capsule, or a liquid-Usually takes 30-60 minutes before working

Time needed before a drug takes effect is the onset of action

RoutesRoutes ofof administration..administration..

5/25/2010

Get into groups of 4

please!

5/28/2010

What are your goals for next school

year?

-Parenteral route: all other methods other than oral administration

-Onset of Action for parenteral can be very quick

-4 most common parenteral routes: -1. Metered-Dose Inhaler: used to deliver meds directly to lungs for rapid action (min. side effects)-2. Transdermal Patch: deliver a constant amount of drug over an extended period of time (usually 24 hr) -convenient, consistent if hairless, no cuts etc-3. Injections: used for rapid effect (ex. anesthesia) - subcutaneous (SC) (arm, abdomen, front thigh) - usually 25 gauge or smaller, ½ inch in length (larger number = thinner needle) - intramuscular (IM) (shoulder, buttocks, thigh)

- usually 23 gauge or larger, 1-1 ½ inches-4. Intravenous; directly in vein, rapid or irritating for SC/IM tissue

RoutesRoutes ofof administration..administration..

•In order for a drug to be effective, the

proper plasma

concentration of the drug needs to be

achieved

•High enough for effect but not too high for harmful effects to

occur

Therapeutic Range: min-max range to achieve objective

Pharmacokinetics: study of 4 processes that affect plasma concentration of drugs (changes based on weight, gender, age and liver function)

Pharmacokinetics

-1. Absorption: the process by which a drug enters the plasma

-oral: must dissolve in stomach fluid or intestines, pass through membranes of GI track & blood vessels before reaching the plasma

-occurs through diffusion (molecules in an area where concentrated randomly move to an area where they are less concentrated (no set direction)

- 2 characteristics which determine the speed of absorption: dissolve time & how easily they can diffuse through the membranes

-2. Distribution: where the drug goes after entering plasma (some binds to proteins, some leaves plasma and goes to tissues)

-will be present in all bodily fluids, only small amount goes to where it will exert its effects

PharmacokineticsPharmacokinetics

-3. Transformation: is the chemical change that takes place in a drug after it has been absorbed by the body.

- most changes occur in liver as the liver alters the drug to make it more water-soluble for easy removal from the body and some changes destroy the activity of a drug

-4. Elimination: process that removes drugs from the body

-most drugs primarily eliminated in urine-also feces, sweat, tears, saliva, &

breast milk

PharmacokineticsPharmacokinetics

Effects of Individual Differences on Maintenance Doses:

Dosage: the amount of a drug to be administered

•the amount and frequency are sometimes different for 2 people of the same body weight

•other factors: activity of the digestive tract, percentage of body fat, age, malnutrition, dehydration, liver disease

DOSAGESDOSAGES

People responsible for administering drugs: Must be certified or licensed in fieldMay need to pass administration testMust take it seriously as errors can cause serious or even fatal consequencesMust have physician’s order

Written in client’s chart or scriptShould include name of drug, amount of drug prescribed, frequency of administration, route of administration

DOSAGES cont…DOSAGES cont…

LABELS Known unit on hand: grams/mg of drugKnown dosage form: typical amount of drug for which you are given the g/mg equivalent (ex. Bottle of cough syrup indicates that there are 125 mg per 5 ml)Dose Ordered: the amount of grams or mg orderedUnknown amount to be given: what you are trying to determine/ the amount of medication to be given

(May require conversions if not listed in same units)

LABELSLABELS

THE END