Basic Pharmacology Review

8/2/2019 Basic Pharmacology Review

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Paramedic Inter FacilityTransfer

TrainingPHARMACOLOGY

Review



PHARMACOLOGY

Review Quiz



• Briefly review information that youhave already had in your paramedic

programs.

• The purpose of this program is not toteach new concepts of pharmacology

Goals of the Pharmacology Review



Medication and Transport

• The most common reason that you willbe asked to transport a patient utilizing

the PIFT module will be because thepatient requires administration ormonitoring of a medication or

medications other than those normallycarried in the paramedic drug box.




• The new PIFT module allows anappropriately trained paramedic to

administer or monitor 18 classes ofmedications, as well as OTCmedications




Potentially, this could

involve as many as several hundred different medications .



This is a significantresponsibility. – Safe, effective transport of patients

requires sound, fundamental knowledge of basic principles of

pharmacology.



IMPORTANTPHARMACOLOGICAL 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 thesame drug. Caused by buildup in the blood.



• Hypersensitivity

– A reaction to a drug that is more profound thanexpected and which often results in an exaggeratedimmune response

• Idiosyncrasy – A reaction to a drug that is significantly different from

what is expected

• Indication

– The medical condition for which the drug has proventherapeutic value



• Parenteral

– Any route of administration other than the digestivetract

• Pharmacodynamics

– Study of the mechanisms by which drugs act to

produce biochemical or physiological changes in thebody

• Pharmacokinetics

– Study of how drugs enter the body, reach their site ofaction and are eliminated from the body



• Potentiation – The enhancement of a drug’s effect by another drug

– Eg. promethazine may enhance the effect ofmorphine; 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 actingindependently



• Therapeutic Action

– The intended action of a drug given in an appropriatemedical 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 andthe 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 thedesired effect

• Untoward Effect

– A side effect of a drug that is harmful to the

patient



PHARMACOKINETICS

• Study of the metabolism and actionof drugs

•Particularly emphasizes thefollowing:

1. Absorption

2. Distribution

3. Biotransformation

4. Excretion



ABSORPTION

• The movement of a drug from its

point of entry into the body intosystemic 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 ofabsorption 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 areinactivated and transformed into a

form that can be eliminated fromthe body



BIOTRANSFORMATION

• Inactive forms are called metabolites

• Rate of transformation will determinehow often a drug must be administered

– Eg. Epinephrine transforms in 3-5 minutes

• The liver is the most significant organin the transformation process



EXCRETION

• The process of eliminatingdrugs from the body



EXCRETION

• Primarily accomplished through thekidneys but may also involve the liver,

the lungs, intestines, sweat andmammary glands



PHARMACODYNAMICS

How a drug works and how we

can expect the body torespond to the administration

of a drug



PHARMACODYNAMICS

• Most drugs work through interactionswith 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 theprinciple 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 dividedinto afferent and efferent divisions.

• The section of the efferent division that

controls involuntary bodily functions isknown as the Autonomic Nervous System.

• These functions include cardiac function,body temperature, smooth muscle, glandfunction 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 andnorepinephrine

– Chemical substances that facilitate excitation or inhibition of target cells



• A drug that stimulates the sympatheticnervous system is known as asympathomimetic or adrenergic agent

• A drug that inhibits the sympatheticnervous system is called asympatholytic 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 aParasympathomimetic or cholinergic drug – Eg. Prostigmine

• A drug that blocks or inhibits the system is

called a Parasympatholytic or anticholinergicdrug – Eg. Atropine



Classifications of Medications

• Anticoagulants• Anticonvulsants

• Antidiabetics

• Antidysrhythmics

• Antihypertensives

• Anti-infectives

• Antipsychotics

• CardiacGlycosides

• Corticosteroids

• Drotrecogin

• GI Agents• IV fluids• Narcotics• Parenteral Nutrition

• Platelet AggregationInhibitors

• Respiratory Medications• Sedatives

• Vasoactive agents



GENERAL CONCEPTS

• Check transfer order carefully to be surethat all medications ordered are permittedunder 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.



• Ask the physician or RN to reviewmedication 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 toreach receiving facility and calculate

the amount of the drug you will needto reach your destination.

– Allow for unforeseen delays.

GENERAL CONCEPTS



• Check to be sure that you have theright drug and the right concentration.

• Check expiration dates of allmedications.

GENERAL CONCEPTS



• Be sure that you thoroughly

understand how to use the infusion

pump being supplied by the hospital – Are you able to troubleshoot potentialproblems?

• Check IV site for patency, redness,etc.

GENERAL CONCEPTS



• Be sure to have a drug reference bookavailable 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 becomesnecessary to administer another drug toascertain possible interaction problems

GENERAL CONCEPTS



• OK, let’s look at the drugclassifications in the PIFT program

Basic Pharmacology Review

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