Transcript Basic PHARMACOLOGY Review

Paramedic Inter Facility
Transfer
Training
PHARMACOLOGY
Review
PHARMACOLOGY
Review Quiz
Goals of the Pharmacology Review
• Briefly review information that you
have already had in your paramedic
programs.
• The purpose of this program is not to
teach new concepts of pharmacology
Medication and Transport
• The most common reason that you will
be asked to transport a patient utilizing
the PIFT module will be because the
patient requires administration or
monitoring of a medication or
medications other than those normally
carried in the paramedic drug box.
Medication and Transport
• The new PIFT module allows an
appropriately trained paramedic to
administer or monitor 18 classes of
medications, as well as OTC
medications
Medication and Transport
Potentially, this could
involve as many as
several hundred
different medications.
This is a significant
responsibility.
– Safe, effective transport of patients
requires sound, fundamental
knowledge of basic principles of
pharmacology.
IMPORTANT
PHARMACOLOGICAL TERMS
• Antagonism
– The opposition between 2 or more medications ex.
narcotics and Naloxone
• Bolus
– A single, often large dose of a drug. Often the initial
dose
• Cumulative action
– An increased effect caused by multiple doses of the
same drug. Caused by buildup in the blood.
• Hypersensitivity
– A reaction to a drug that is more profound than
expected and which often results in an exaggerated
immune response
• Idiosyncrasy
– A reaction to a drug that is significantly different from
what is expected
• Indication
– The medical condition for which the drug has proven
therapeutic value
• Parenteral
– Any route of administration other than the digestive
tract
• Pharmacodynamics
– Study of the mechanisms by which drugs act to
produce biochemical or physiological changes in the
body
• Pharmacokinetics
– Study of how drugs enter the body, reach their site of
action and are eliminated from the body
• Potentiation
– The enhancement of a drug’s effect by another drug
– Eg. promethazine may enhance the effect of
morphine; also alcohol and barbiturates
• Refractory
– The failure of a patient to respond as expected to a
certain medication
• Synergism
– The combined action of 2 or more drugs that is
greater than the sum of the 2 drugs acting
independently
• Therapeutic Action
– The intended action of a drug given in an appropriate
medical setting
• Therapeutic Threshold
– The minimum amount of a drug that is required to
cause the desired response
• Therapeutic Index
– The difference between the therapeutic threshold and
the amount of the drug considered to be toxic
– Often referred to as Safe and Effective range
• Tolerance
– The decreased sensitivity or response to a
drug that occurs after repeated doses
– Increased doses are required to achieve the
desired effect
• Untoward Effect
– A side effect of a drug that is harmful to the
patient
PHARMACOKINETICS
• Study of the metabolism and action
of drugs
• Particularly emphasizes the
following:
1. Absorption
2. Distribution
3. Biotransformation
4. Excretion
ABSORPTION
• The movement of a drug from its
point of entry into the body into
systemic circulation
ABSORPTION
• Factors influencing rate of absorption:
• Drug concentration
• Site of absorption
• pH of the drug
– Acids into acids, etc.
• Status of circulation
• Solubility
– Water based vs. oil based
DISTRIBUTION
• The manner in which a drug is
transported from the site of
absorption to the site of action
DISTRIBUTION
• Influenced by several factors:
• Cardiovascular function
–HR, BP, EF
• Physical barriers
–Blood-brain and placenta barriers
BIOTRANSFORMATION
• The process by which drugs are
inactivated and transformed into a
form that can be eliminated from
the body
BIOTRANSFORMATION
• Inactive forms are called metabolites
• Rate of transformation will determine
how often a drug must be administered
– Eg. Epinephrine transforms in 3-5 minutes
• The liver is the most significant organ
in the transformation process
EXCRETION
• The process of eliminating
drugs from the body
EXCRETION
• Primarily accomplished through the
kidneys but may also involve the liver,
the lungs, intestines, sweat and
mammary glands
PHARMACODYNAMICS
How a drug works and how we
can expect the body to
respond to the administration
of a drug
PHARMACODYNAMICS
• Most drugs work through interactions
with receptor sites.
– These are protein coatings found on the outer
surface of the cell membrane.
– Generally, when a drug binds or attaches to a
receptor site, a chemical reaction occurs that
initiates the desired physiological or
therapeutic response.
– Such drugs are called agonists.
Some drugs work through the
principle of antagonism
– In such cases, a drug competes with
another drug or chemical for position at a
receptor site.
– We see this with Naloxone which competes
with narcotic drugs
• In this case Naloxone would be an antagonist.
AUTONOMIC NERVOUS SYSTEM
• The Peripheral nervous system is divided
into afferent and efferent divisions.
• The section of the efferent division that
controls involuntary bodily functions is
known as the Autonomic Nervous System.
• These functions include cardiac function,
body temperature, smooth muscle, gland
function and arterial blood pressure.
AUTONOMIC NERVOUS SYSTEM
• Sympathetic nervous system
• Parasympathetic nervous system
SYMPATHETIC NERVOUS SYSTEM
• Prepares body to deal with stress
– Fight or flight response
• Neurotransmitters are epinephrine and
norepinephrine
– Chemical substances that facilitate
excitation or inhibition of target cells
• A drug that stimulates the sympathetic
nervous system is known as a
sympathomimetic or adrenergic agent
• A drug that inhibits the sympathetic
nervous system is called a
sympatholytic or anti-adrenergic agent
• Ex. Propanolol ( beta blocker )
PARASYMPATHETIC NERVOUS SYSTEM
• Controls vegetative functions
– Constriction of pupils, slowing of heart rate,
constriction of bronchioles, etc.
• Neurotransmitter is Acetylcholine
• A drug that stimulates the system is called a
Parasympathomimetic or cholinergic drug
– Eg. Prostigmine
• A drug that blocks or inhibits the system is
called a Parasympatholytic or anticholinergic
drug
– Eg. Atropine
Classifications of Medications
•
•
•
•
•
•
•
•
Anticoagulants
Anticonvulsants
Antidiabetics
Antidysrhythmics
Antihypertensives
Anti-infectives
Antipsychotics
Cardiac
Glycosides
• Corticosteroids
• Drotrecogin
•
•
•
•
•
GI Agents
IV fluids
Narcotics
Parenteral Nutrition
Platelet Aggregation
Inhibitors
• Respiratory Medications
• Sedatives
• Vasoactive agents
GENERAL CONCEPTS
• Check transfer order carefully to be sure
that all medications ordered are permitted
under the PIFT program.
• Be sure that order specifies:
– Dosage information
– Times of administration (where applicable)
– Indications for changes or discontinuance.
– Eg. Nitroglycerin dosage is often altered
based on pain and/or BP.
GENERAL CONCEPTS
• Ask the physician or RN to review
medication if it is one that you are not
familiar with.
– Discuss potential adverse reactions and
how to deal with them.
– Use resources to double check
GENERAL CONCEPTS
• Determine how long it will take to
reach receiving facility and calculate
the amount of the drug you will need
to reach your destination.
– Allow for unforeseen delays.
GENERAL CONCEPTS
• Check to be sure that you have the
right drug and the right concentration.
• Check expiration dates of all
medications.
GENERAL CONCEPTS
• Be sure that you thoroughly
understand how to use the infusion
pump being supplied by the hospital
– Are you able to troubleshoot potential
problems?
• Check IV site for patency, redness,
etc.
GENERAL CONCEPTS
• Be sure to have a drug reference book
available in your ambulance
• Review drug reference for detailed
information about the drug.
– Review side effects, adverse reactions,
dosing, interactions, etc.
• Contact medical control if it becomes
necessary to administer another drug to
ascertain possible interaction problems