Basic Pharmacology Review 1u2i3y

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 istration 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 ister 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 • 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 istration 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 istered – 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 istration 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 istration (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.

• medical control if it becomes necessary to ister another drug to ascertain possible interaction problems

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