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Pharmacology
PT020D
Lecture 2
Course Objective #14
• Identify medications commonly prescribed for D.D.
clients by both generic and trade names.
Commonly prescribed meds
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Vitamins
Cardiac meds
Muscle relaxants
Anti-anxiety
Anti-convulsants
Course Objective #15
• Describe the following mechanisms of drug
action:
– Altering existing cellular functions
– Altering cellular environment
Alteration in Cellular Function
• Drugs CANNOT create new function!
• Drugs CAN alter existing cellular function
Receptor-mediated drug action
• Agonist
–Enhances
• Antagonist
–Blocks
What are the 2 types of Antagonists?
• Competitive
• Non-competitive
Drug Action
Alter
function
Agonist
Competitive
Alter
environment
Antagonist
Noncompetitive
Physically
Chemically
Alteration in Cellular environment
Physically
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Chemically
Osmotic pressure • Alter body
fluids
Lubrication
Absorption
Surface conditions
Course objective #16
• Differentiate between commonly used drugs
according to:
A.
B.
C.
D.
E.
F.
G.
H.
Name
Classification
Mechanism of action
Indications for use
Contraindications
Adverse drug effects
Drug interactions
Drug incompatibilities
The name game
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Chemical name
Generic name
Official name
Trade name / brand name
The NAME game
Chemical
Scientific terms – describes the molecular
structure
Generic
General name used by any company
“non-proprietary”
Official
Name given by FDA
Trade
Specific company – marketing name
Classification “Class”
• Common action
• Frequently common
–Side-effects
–Adverse reactions
Mechanism of Action
• Pharmacodynamics
– “The study of the drug mechanism that produce
biochemical or physiologic changes in the body”
Mechanism of Action /
Pharmacodynamics
• Admin. Rx 
• Systemic circulation

• Entire body
Mechanism of Action
• 1o Effect
– Desired / therapeutic
• 2o Effect
– All other effects
–+/– “side-effects”
– expected
Mechanism of Action
Affinity for certain organs
“Target Sites”
Alt. function
Alt environment
Course Objective #17
• Describe the following indications for use of
drugs:
– Primary
– Adjunctive
– Non-labeled use
– Investigative use
Indications for Use
• Valid reason
• What is the opposite of indication?
– Contraindication
Indications
• Primary
–Main use
Indications
• Adjunctive
–Used along with
Indication
• Non-labeled use
–Supported by research
Indications for use
• Investigative use
• Only in FDA approved studies
Contraindication
• Published
• When to Avoid or D/C
Adverse Drug Reactions
• Undesirable Rx
effects
Types of Adverse Rx effects
• Allergic
Adverse Drug Reactions
• Allergic Reaction
–Hypersensitivity
–Immune response
• “antigen”
– Anaphylactic Shock
S&S Anaphylactic Shock
Resp
C/V
Skin
G/I
Dyspnea, bronchospasm
 B/P + h P =
Cardiac Arrest
Urticaria + Pruritus
N/V
Adverse Drug Reactions
• Rx Idiosyncrasy
– Unusual reaction
Adverse Drug Reactions
• Rx Tolerance
– response to Rx
Adverse Drug Reactions
• Cumulative Rx Effect
– metabolism of Rx 
–h levels
Adverse Drug Reactions
• Toxic Reaction
– h levels 
– Toxic / harmful
Adverse Drug Reactions
• Teratogenic
– Rx + PG =
– Congenital defects
Drug interactions
• Drug – Drug
– When 1 Rx
interacts with
other Rx
• Drug - Food
Drug-to-drug
• Additive Rx reaction
–1 + 1 = 2
Drug-to-drug
• Synergistic Rx reaction
–1 + 1 = 3
Drug-to-drug
• Antagonistic Rx reaction
–1 + 1 = 0 (or 1)
What should you do?
• You are mixing drugs in a syringe to give a parenteral
injection when you notice white particles forming in
the syringe.
• What should you do?
• Do NOT give the drug!
Drug-to-Food
• Food 
–+/- absorption
Rx bottle reads: Take on an empty
stomach
• What are the rules????
• (tell your neighbor)
– 1hr ac
– 2hr pc
Rx bottle reads: Take with meals
• Minimize GI irritation
Insoluble Food-Rx mix
• Rx + Food = Insoluble
–(Cannot be absorbed)
– absorption   effect
Course Objective #18
• Explain how absorption, distribution,
biotransformation and excretion effect:
– The concentration of drug at body sites
– The concentration of drug metabolites at body
sites
– The time for drug concentration to develop or
change
Pharmacokinetics
• What the body does to the Rx
– Absorption
– Distribution
– Metabolism
• Half-life
– Excretion
Biotransformation
Absorption
• How Rx is “made available”
• Most PO Rx are absorbed into the body
from the….
– Small intestine
Factors that Affect Absorption
• Route
• Solubility
Distribution
• Rx carried from absorption site  tissue
– *C/V system!
Course objective #20
• Explain how distribution of a drug is
effected by the blood-brain barrier.
Blood-brain Barrier
• Selective permeability
• Impermeable to MOST Rx
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Hypertension
Hyperosmolar
Radiation
Infection
Trauma
Development
• Blood-Brain Barrier makes the
brain impermeable to Most drugs
Metabolism
• What is the other name for Rx
metabolism?
–Biotransformation
–Breakdown of the drug
Half-life
• Time required for body to
eliminate 50% of the drug
Excretion
• Elimination of Rx from body
Explain how…
• Absorption
• Distribution
• Biotransformation
• Excretion
Effect
• Rx concentration
in the body
Course Objective #19
• Describe how the rate of absorption of a drug is
affected by:
– Route of administration
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Oral
Sublingual
Parenteral
Subcutaneous
Intramuscular
Intravenous
– Interfering factors
• Stomach contents and acids
• Tissue problems at site of injection, topical, inhalant
2 biggest variables affecting
absorption?
• Route
• Circulation
Categories of Rx administration
• Enteral
• Parenteral
• Percutaneous
Enteral
• Directly into GI
–Oral
–Rectal
–Nasogastric
Parenteral
• Bypasses GI
–Subcutaneous (Subcut)
–Intramuscular (IM)
–Intravenous (IV)
Percutaneous
• Skin
–Inhalation
–Sublingual
–Topical
Enteral • With fluids
– 8 oz water
• Food
Parenteral
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•
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Correct tissue
Reconstitute
Assess tissue
Heat 
– h absorption
• Cool 
–  absorption
Percutaneous
• Topical
– Skin thickness
– Hydration
– Newborns 
• h absorption
• Inhaled
– Depth of breath
– Fineness of droplet
– Hydration
Course Objective #21
• Describe how biotransformation
facilitates elimination of drug
metabolites.
Turn to your neighbor…
• Define the term biotransformation
– Metabolism
Course objective #22
• List the four body processes through
which drugs or their metabolites are
eliminated.
Course Objective #23
• Explain how the following factors which
influence individual pharmacological response:
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Age
Gender
Body weight
Basal metabolic rate
Disease states
Genetic factors
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Time/route
Tolerance
Nutrition
Smoking
Age
• Infant / Child
–< dose
• Elderly
–< dose
–Polypharmacy
Gender
• Male vs. Female
–Dose amount???
• Male > Female
–WHY????
–Fat:Water
Body Weight
• Dosing based on
– 170 lbs
Basal Metabolic Rate
• h BMR 
– __?___ dose
– h
Disease State
• What diseases might effect
pharmacological responses the most?
– C/V
• Distribution
– Liver
• Metabolism
– Kidney
• Excretion
Genetic Factors
Time/Route
• Place the following in order of Speed:
– IV
– PO
– IM
– Subcut
Time/Route
• Place the following in order of Speed:
– 1. IV
– 4. PO
– 2. IM
– 3. Subcut
Tolerance
• What is the difference between drug tolerance and
drug dependence?
Tolerance
• Requires h dose to produce same effect
Dependency
• AKA: Addiction
–Cannot control ingestion
–Physical
• Withdrawal
–Psychological
• Emotionally attached
Nutrition
Smoking
• What effect does smoking have on
BMR?
–__?___ dosing
Course Objective #24
• Calculate accurate medication
dosages using dimensional analysis.