Module 1-1 Flashcards
what are the 6 rights of medication administration?
right drug, right dose, right time, right route, right patient, right documentation
define drug
Any chemical that affects the physiologic
processes of a living organism
define pharmacology
study or science of drugs
Chemical name
Describes the drug’s chemical composition and
molecular structure
Generic name (nonproprietary name)
Name given by the United States Adopted Name
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Council
Trade name (proprietary name)
Brand name, The drug name has a registered trademark; use
of the name is restricted by the drug’s patent owner
(usually the manufacturer)
naming example:
chemical: 2-isbuphenyl blah blah
generic name: ibuprofen
trade name: Motrin
Pharmaceutics
The study of how various drug forms
influence pharmacokinetic and
pharmacodynamic activities
Pharmacokinetics
The study of what the body does to the drug Absorption Distribution Metabolism Excretion
Pharmacodynamics
The study of what the drug does to the body The mechanism of drug actions in living tissues
Pharmacotherapeutics
The use of drugs and the clinical indications
for drugs to prevent and treat diseases
Pharmacognosy
The study of natural (plant and animal) drug
sources ie. opium plant
drug abosorption-fastest to slowest
liquids elixirs and syrups, then suspension solutions, powders, capsules, tablets, coated tablets, enteric-coated tablets
Pharmacokinetics: Absorption
The rate at which a drug leaves its site of
administration, and the extent to which
absorption occurs. Includes bioavailability and bioequivalency
bioavailability
the percent of administered dose of unchanged drug that reaches systemic circulation. Impeded by complete absorption and first pass effect
bioequivalency
when two different formulations may have comparable bioavailability
Factors That Affect Absorption
Absorption characteristics vary according to
the dosage form and route:
Food or fluids administered with the drug
Dosage formulation
Status of the absorptive surface
Rate of blood flow to the small intestine
Acidity of the stomach
Status of GI motility
Routes
A drug’s route of administration affects the
rate and extent of absorption of that drug Enteral (GI tract) - easy cheap
Parenteral - fastest
Topical - slower, longer duration, more localized
Enteral route
The drug is absorbed into the systemic circulation through the oral or gastric mucosa or the small intestine Oral Sublingual Buccal Rectal
First-Pass Effect
The metabolism of a drug and its passage
from the liver into the circulation
A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic circulation (high first-pass effect)
The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation
Parenteral Route
Intravenous (fastest delivery into the blood circulation) Intramuscular Subcutaneous Intradermal Intraarterial Intrathecal - into spinal column Intraarticular - into a joint
Topical Route
Skin (including transdermal patches)
Eyes
Ears
Nose
Lungs (inhalation)
Rectum - half has first pass effect has does not
VaginaDistribution
The transport of a drug in the body by the
bloodstream to its site of action
Protein-binding
Water soluble vs. fat soluble - if lipid soluble it will penetrate cell membranes easier
Blood-brain barrier - small lipid soluble get through easier
Areas of rapid distribution: heart, liver,
kidneys, brain
Areas of slow distribution: muscle, skin, fat
Metabolism/Biotransformation
The biochemical transformation of a drug into an inactive metabolite, a more soluble compound, or a more potent metabolite Liver (main organ) Skeletal muscle Kidneys Lungs Plasma Intestinal mucosa
Metabolism/Biotransformation
Biologic transformation of a drug into:
An inactive metabolite
A more soluble compound
A more potent metabolite
Factors that decrease metabolism
Cardiovascular dysfunction
Renal insufficiency
Starvation
Obstructive jaundice - blockage in bile duct
Slow acetylator
Erythromycin or ketoconazole drug therapy- inhibit enzymes
Factors that increase metabolism
Fast acetylator- genetically determined
Barbiturate therapy - phenylbarbitol
Rifampin therapy
Delaying drug metabolism causes:
Accumulation of drugs
Prolonged action of the drugs ->drug toxicity, higher blood levels for longer periods of time
Stimulating drug metabolism causes:
Diminished pharmacologic effects
Excretion
The elimination of drugs from the body
Metabolize drugs to make them more polar to be able to get rid of them
Kidneys (main organ)
Liver
Bowel
Biliary excretion
Enterohepatic recirculation - break it down and it gets reabsorbed
Half-life effectively removed after about 5 half-lives 1 half-life - 50% removed 2 half-lives - 75% removed 3 half-lives - 87.5% removed 4 half-lives - 93.75% removed 5 half-lives - 97% removed
The time it takes for one half of the original amount of a drug to be removed from the body A measure of the rate at which a drug is removed from the body Most drugs considered to be effectively removed after about five half-lives Steady state - amount of drug removed via elimination = to amount absorbed. That is when the drug is at steady state, after about 4 to 5 half-lives
Onset, Peak, and Duration
Onset
The time it takes for the drug to elicit a
therapeutic response
Peak
The time it takes for a drug to reach its
maximum therapeutic response
Duration
The time a drug concentration is sufficient to
elicit a therapeutic response
Therapeutic Drug Monitoring
Peak level
Highest blood level- too high causes toxicity
Trough level (nadir)
Lowest blood level - too low inefficient
Pharmacodynamics:
Mechanisms of Action
Receptor interactions
Enzyme interactions
Nonselective interactions
Pharmacotherapeutics:
Types of Therapies
Acute therapy-short term, antibacterial cure
Maintenance therapy- hypertension or schitzo
Supplemental/replacement therapy- insulin
Palliative therapy- make someone comfortable in terminal in terminal state opiods
Supportive therapy-fluids and electrolytes ex. flu
Prophylactic therapy-to prevent something ex. antibiotics prior to surgery or traveling
Empiric therapy- clinical probability therapy antibiotic based on signs and symptoms
Contraindications
Any characteristic of the patient, especially a disease state, that makes the use of a given medication dangerous for the patient. Liver damage, kidney disease
It is important to assess for contraindications!
Monitoring
Therapeutic index
Ratio of a drug’s toxic level to the level that
provides therapeutic benefits
Tolerance
Decreasing response to repeated drug doses-
Dependence
Physiologic or psychological need for a drug
Monitoring (cont’d)
Interactions may occur with other drugs or food
A drug interaction is the alteration of a drug’s action by:
Other prescribed drugs
Over-the-counter medications
Herbal therapies
Monitoring (cont’d)
Drug interactions
Additive- 1+1=2
Synergistic-1+1=3 diaretic and aceinhibitor
Potentiation-one of the drugs does not have an effect
Antagonistic- tetracycline and antacid
Incompatibility- drugs cannot be mixed in an iv
Drug Sources
Four main sources for drugs Plants- caffeine from coffee, nicotine from tobacco Animals- insulin, heparin, hormones Minerals- sodium chloride, Laboratory synthesis- most drugs,
