5/23/2012
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5/23/2012. What do you think of when you hear the word “pharmacology”?. Pharmacology. 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 - PowerPoint PPT PresentationTRANSCRIPT
5/23/2012
What do you think of when you
hear the word “pharmacology”?
Pharmacology
Delete box or call out text or list of services
goes here
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
http://player.discoveryeducation.com/index.cfm?guidAssetId=A4B2B75F-C34E-41E5-9DFD-476568A30FA8&blnFromSearch=1&productcode=US
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