PHARMACOLOGY
TUESDAY 9:00 - 12:00 NN
BSN 2.1 FLORENCE
INTRODUCTION TO PHARMACOLOGY
PHARMACOLOGIC PRINCIPLES • Pharmaceutics
➢ The study of how various drug forms influence
• Drug pharmacokinetic and pharmacodynamic
➢ Any chemical that affects the processes of a activities
living organism
• Pharmacokinetics
• Pharmacology ➢ The study of what the body does to the drug
➢ The study or science of drugs ➢ The mechanism of drug actions I living tissues.
Drug Name • Pharmacodynamics
• Chemical name ➢ The study of what the drug does to the body:
➢ The drug’s chemical composition and ➢ The mechanism of drug actions in living tissues
molecular structure • Pharmacotherapeutics
• The use of drugs and the clinical indications for
• Generic name (non-proprietary name) drugs to prevent and treat diseases.
➢ Name which contains the active ingredient
➢ Same efficacy as the branded ones • Pharmacognosy
• Trade name (brandname/trademark/proprietary • The study of natural (plant and animal) drug
name) sources
➢ The drug has a registered trademark; use of the Drug Administration
name restricted by the drug’s owner (usually
the manufacturer) ROUTES FORMS
➢ has the symbol ® or TM beside it A. ENTERAL
Pharmacologic Principles: Drug Names • Oral • Capsule, tablet
• NGT • Syrup, suspension
• Chemical name B. PARENTERAL
➢ N-acteyl-p-aminophenol • Intravenous • Ampule; vial
• Intramuscular
• Generic name
• Intradermal
➢ Paracetamol
• Subcutaneous
• Trade name C. TOPICAL • Cream,
➢ Biogesic ointment
• Chemical name Examples of Drug Forms
➢ 2S,5R,6R)-6-[[(2R)-2-amino-2-(4-
hydroxyphenyl)acetyl]amino]-3,3-dimethyl-7-oxo-
4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic
acid
• Generic name
➢ Amoxicillin
• Trade name
➢ Himox
Pharmacologic Principles
• Pharmaceutics
• Pharmacokinetics
• Pharmacodynamics
• Pharmacotherapeutics
• Pharmacognosy
Afreen N. Abdurahman
Drug Absorption of Various Oral Preparations or reaching the systemic circulation (high first-
Forms pass effect).
➢ The same drug—given IV—bypasses the liver,
Liquids, elixirs, syrups Fastest preventing the first-pass effect from taking
Suspension solutions place, and more drug reaches the circulation.
Powders
Capsules
Tablets
Coated tablets
Enteric-coated tablets Slowest
When a drug is administered it undergoes 2 phases:
1) Pharmacokinetic Phase
2) Pharmacodynamics Phase
Pharmacokinetics
➢ Process of drug movement throughout the
body necessary for drug action
➢ It is what the body does to the drug.
➢ 4 processes of Pharmacokinetics
a. Absorption Bioavailability (BA)
b. Distribution
c. Metabolism (biotransformation) ➢ The percentage of available administered
d. Excretion drug for activity or use
➢ BA of orally administered drugs is always less
ABSORPTION than 100%
➢ BA of IV drugs is 100%
➢ It is the movement of the drug from the site of
administration up to the bloodstream Factors affecting Bioavailability (BA)
Factors That Affect Absorption 1) Drug Form
• Administration route of the drug 2) Route of Administration
• Food or fluids administered with the drug 3) Gastric Mucosa and Motility
• Dosage formulation 4) Food and Other Drugs
• Status of the absorptive surface 5) Changes in Liver Metabolism
• Rate of blood flow to the small intestine Routes
• Acidity of the stomach
• Status of GI motility • Routes that bypass the liver:
– Sublingual Transdermal
Routes – Buccal Vaginal
➢ A drug’s route of administration affects the rate – Rectal Intramuscular
and extent of absorption of that drug. – Intravenous Subcutaneous
• Enteral – Intranasal Inhalation
• Parenteral *Rectal route undergoes a higher degree of first-
• Topical pass effects than the other routes listed.
Enteral Route Parenteral Route
➢ Drug is absorbed into the systemic circulation • Intravenous
through the oral or gastric mucosa, the small • Intramuscular
intestine, or rectum. • Subcutaneous
• Oral • Intradermal
• Sublingual • Intrathecal
• Buccal • Intraarticular
• Rectal *Fastest delivery into the blood circulation
First-Pass Effect Topical Route
• Skin (including transdermal patches)
➢ The metabolism of a drug and its passage from • Eyes
the liver into the circulation. • Ears
➢ A drug given via the oral route may be • Nose
extensively metabolized by the liver before • Lungs (inhalation)
• Vaginal mucosa
Afreen N. Abdurahman
DISTRIBUTION EXCRETION
➢ The transport of a drug in the body by the ➢ The elimination of drugs from the body
bloodstream to its site of action. • Kidneys (main organ)
• Protein-binding effect • Liver
• Water soluble vs. fat soluble • Bowel
• Blood-brain barrier ➢ biliary excretion
•Areas of rapid distribution: heart, liver, kidneys, ➢ enterohepatic circulation
brain • Lungs, saliva, sweat, breast milk
• Areas of slow distribution: muscle, skin, fat
METABOLISM
➢ Also known as Biotransformation
➢ The biologic transformation of a drug into an
inactive metabolite, a form which can be
easily excreted.
• Liver (main organ)
• Kidneys
• Lungs
• Plasma
• Intestinal mucosa
Factors That Decrease Metabolism
• Cardiovascular dysfunction
• Renal insufficiency
• Starvation
• Obstructive jaundice
• Slow acetylator Pharmacodynamics
• Erythromycin or ketoconazole drug therapy
• Drug actions:
Factors That Increase Metabolism ➢ The cellular processes involved in the drug and
cell interaction
• Fast acetylator
• Barbiturates • Drug effect:
• Rifampin therapy ➢ The physiologic reaction of the body to the
drug
Delayed Drug Metabolism Results In
• Onset
• Accumulation of drugs ➢ The time it takes for the drug to elicit a
• Prolonged action of the effects of the drugs therapeutic response.
Stimulating Drug Metabolism Causes • Peak
➢ The time it takes for a drug to reach its
• Diminished pharmacologic effects maximum therapeutic response.
Half-life • Duration
➢ The time it takes for one half of the original ➢ The time a drug concentration is sufficient to
amount of a drug in the body to be removed. elicit a therapeutic response
➢ A measure of the rate at which drugs are
removed from the body.
Loading Dose
➢ Giving a large initial dose to achieve the
steady state (drug level ) faster
Afreen N. Abdurahman
• Supportive therapy
• Prophylactic therapy
Pharmacodynamics: Mechanisms of Action
Pharmacotherapeutics: Monitoring
The ways by which drugs can produce therapeutic
effects: ➢ The effectiveness of the drug therapy must be
➢ Once the drug is at the site of action, it can evaluated.
modify the rate (increase or decrease) at ➢ One must be familiar with the drug’s
which the cells or tissues function. ➢ Intended therapeutic action (beneficial)
➢ A drug cannot make a cell or tissue perform a ➢ And the drug’s unintended but potential side
function it was not designed to perform. effects (predictable, adverse drug reactions).
• Receptor interaction • Therapeutic index
• Enzyme interaction • Drug concentration
• Nonspecific interactions • Patient’s condition
• Tolerance and dependence
• Interactions
• Side effects/adverse drug effects
• Therapeutic Index
➢ The ratio between a drug’s therapeutic
benefits and its toxic effects
• Tolerance
➢ A decreasing response to repetitive drug
doses
• Dependence
DOSE-RESPONSE RELATIONSHIP (CURVE) ➢ A physiologic or psychological need for a
drug
Interactions may occur with other drugs or food
• Drug interactions: the alteration of action of
a drug by:
– Other prescribed drugs
– Over-the-counter medications
– Herbal therapies
Interactions
• Additive effect
• Synergistic effect
• Antagonistic effect
ONSET-PEAK-DURATION • Incompatibility
Medication Misadventures
• Adverse drug events
➢ ALL are preventable
➢ Medication errors that result in patient
harm
• Adverse drug reactions
➢ Inherent, not preventable event occurring
in the normal therapeutic use of a drug
\
➢ Any reaction that is unexpected,
undesirable, and occurs at doses normally
used
Some adverse drug reactions are classified as
Pharmacotherapeutics: Types of Therapies
side effects.
• Acute therapy • Expected, well-known reactions that result in little
• Maintenance therapy or no change in patient management
• Supplemental therapy • Predictable frequency
• Palliative therapy • The effect’s intensity and occurrence is related to
the size of the dose
Afreen N. Abdurahman
Adverse Drug Reaction
An undesirable response to drug therapy
• Idiosyncratic
• Hypersensitivity reactions
• Drug interactions
Iatrogenic Responses
Unintentional adverse effects that are treatment-
induced
• Dermatologic
• Renal damage
• Blood dyscrasias
• Hepatic toxicity
Other Drug-Related Effects
• Teratogenic
• Mutagenic
• Carcinogenic
Afreen N. Abdurahman
