Ch 13 Principles of Pharmacology

What is the defining element of paramedic clinical practice?

Medication administration

What can medications do in terms of patient care?

Correct or decrease the severity of an illness or injury, manage life-threatening conditions, and substantially reduce patient discomfort.

What are the severe consequences of medication errors?

Administering the wrong medication, via the wrong route, incorrect dose, or failing to follow correct technique.

What is pharmacology?

The scientific study of how various substances interact with or alter the function of living organisms.

What historical sources have been used for medication?

Chemicals from plants and animals have been used for centuries to cure diseases and treat symptoms.

What is the purpose of evidence-based guidelines in pharmacology?

To assist clinicians using pharmacologic interventions.

What act regulated medication labels and prevented altering of labels?

The Pure Food and Drug Act of 1906.

What is the role of the US Food and Drug Administration (FDA)?

To approve new medications and remove unsafe medications from use.

What does it mean for a medication to be used 'off-label'?

It means the purpose, dose, or route of administration is not FDA approved.

What is the Controlled Substances Act of 1970?

An act that classifies medications with potential for abuse into five categories (schedules).

What are the primary sources of medication?

Plants, animals, minerals, microorganisms, and synthetic sources.

What are the requirements for medications produced by pharmaceutical companies?

They must have a manufacturing lot number and an expiration date.

What are the three names given to medications?

Chemical name, nonproprietary (generic) name, and brand (proprietary) name.

What is an example of a medication's chemical, generic, and brand names?

Chemical name: 4-chloro-N-furfuryl-5-sulfamoylanthranilic acid; Generic name: furosemide; Brand name: Lasix.

What factors do paramedics consider when using medication reference sources?

Reliability, depth of information, accessibility, cost, availability of updates, and size of materials.

What is a medication monograph?

A medication profile that includes detailed information about the drug.

What does the AHA classification system indicate?

It classifies evidence supporting medication use from strong (Class I) to no benefit (Class III).

What are the requirements for medication storage?

Provide adequate protection, quick access, prevent physical damage, and temperature control.

What must be documented for controlled substances?

Every milliliter or milligram must be documented for ordering, administration, and disposal.

What is pharmacodynamics?

The alteration in body function or processes as medication is administered.

What is pharmacokinetics?

The action of the body on a medication, including absorption, distribution, biotransformation, and elimination.

What activates receptor sites in pharmacodynamics?

Endogenous and exogenous chemicals.

What happens when a medication binds with a receptor site?

Channels in cell walls can open or close, activating biochemical messengers and altering cell function.

What is the significance of 'tall man' lettering in medication names?

It helps distinguish between similar-sounding medication names to prevent errors.

What are the potential toxic effects of medications?

They can arise from incorrect doses, incorrect routes, malfunctions, or unique patient reactions.

What should be avoided in medication storage?

Direct sunlight, extreme temperatures, and physical damage.

What additional measures are required for controlled substances?

They require additional security, record keeping, and disposal precautions.

What are the two types of medications that affect cellular activity?

Agonist medications and Antagonist medications

What is the affinity of agonist medications?

The medication's ability to bind with receptor site(s) and initiate or alter cell action.

What determines the number of bound receptor sites in agonist medications?

Concentration and affinity.

What is the threshold level in the context of agonist medications?

The point at which the initiation of alteration of cellular activity begins.

What happens when all receptor sites become occupied in agonist medications?

The cell's maximum capacity is reached.

Define potency in relation to agonist medications.

The concentration of medication required to initiate a cellular response; higher potency requires a lower dose.

What is efficacy in pharmacodynamics?

The ability to initiate or alter cell activity in a therapeutic or desired manner.

What is the role of antagonist medications?

To bind with receptor sites and prevent cellular response to agonist chemicals.

What are competitive antagonists?

Antagonists that temporarily bind with cellular receptor sites and displace agonist chemicals.

What distinguishes noncompetitive antagonists?

They permanently bind with receptor sites and cannot be overcome by increased doses of agonist chemicals.

What are partial agonist chemicals?

Chemicals that bind to receptor sites and initiate less cellular activity than other agonists.

What are some alternative mechanisms of drug action?

Medications can alter cell function without interacting with receptors, targeting microorganisms, lipids, water, and exogenous toxic substances.

How do antimicrobials function?

They target specific substances present in the cell walls of bacteria or fungi.

What is the function of chelating agents?

They bind with heavy metals to create a compound that can be eliminated.

What is the role of sodium bicarbonate in drug action?

It breaks down into ions, binds with excess hydrogen ions, raises pH, and decreases acidity of body fluids.

What do diuretics do?

They create osmotic changes, alter the distribution of fluids and electrolytes, and enhance urine excretion.

What factors affect weight-based dosing?

Age, weight, environment, genetics, pregnancy, and psychosocial factors.

How does age affect weight-based dosing?

Water-soluble medications may require higher doses for infants than adults, while fat-soluble medications may require higher doses for the elderly.

What are the advantages of weight-based dosing?

It ensures the amount of medication is proportional to the patient's size.

What limitations exist in weight-based dosing?

It requires the patient's weight in kilograms and does not consider alterations in distribution, metabolism, and elimination.

How does hyperthermia affect medication metabolism?

It may increase metabolism of drugs and reduce the amount of drug returned to circulation.

What is the impact of hypothermia on medication effectiveness?

It impairs the effectiveness of medications used in traditional cardiac life support.

What precautions are necessary for genetics in medication dosing?

Extra precautions are required for conditions like primary pulmonary hypertension and sickle cell disease.

What physiologic changes during pregnancy affect medication dosing?

Changes in absorption, distribution, and elimination.

What should be considered regarding medications during pregnancy?

The effect of medication on the fetus and consulting FDA pregnancy risk categories.

What psychosocial factors can affect medication response?

Pain, anxiety, and discomfort can vary among patients, complicating medication administration.

What is the difference between a side effect and an adverse medication effect?

A side effect is a secondary effect of a medication, while an adverse effect is a harmful or undesired reaction.

What are adverse medication effects?

Undesired clinical changes that can be either desirable or harmful.

What are common adverse effects of medications?

Nausea, vomiting, sedation, respiratory depression, dizziness.

What is the therapeutic index?

The relationship between median effective dose (ED50) and median lethal dose (LD50).

What indicates a safe medication in terms of therapeutic index?

A large difference between the median effective dose and median lethal dose.

What is an immune-mediated medication response?

An allergic reaction that occurs in genetically predisposed patients after initial exposure to an allergen.

What is medication tolerance?

Decreased efficacy of medications when taken repeatedly due to down-regulation of receptors.

What is tachyphylaxis?

A rapid decrease in response to a drug after repeated doses.

What are the risks associated with medication abuse?

Prone to misuse and dependence, especially with stimulants and depressants.

What are medication interactions?

Undesirable interference that may increase, decrease, or alter the effect of another medication.

What factors determine the pharmacokinetics of a medication?

Dose, route of administration, and clinical status of the patient.

What is bioavailability?

The percentage of unchanged medication that reaches systemic circulation.

What are the requirements for oral medication administration?

Patient must be responsive and able to swallow.

What is the preferred method of medication administration in prehospital settings?

Intravenous (IV) administration.

What is the bioavailability of intravenous administration?

100%.

What is intraosseous (IO) administration?

A method where a needle is inserted into the bone for medication delivery.

What is the bioavailability range for intramuscular (IM) administration?

75% to 100%.

What is the advantage of subcutaneous (SC) administration?

Slower absorption may prevent adverse cardiovascular effects.

What is the purpose of dermal and transdermal administration?

To deliver a constant dose of medication over a long period.

What is the primary use of sublingual administration?

Often used for medications like Nitroglycerin.

What are the limitations of inhaled or nebulized administration?

Risk of bronchospasm and loss of medication portion.

Why is rectal administration preferred in certain situations?

It is preferred if the patient is unresponsive, having seizures, or unable to swallow.

What is the significance of medication distribution?

It determines how medication moves through the body and its effectiveness.

What is osmosis in the context of medication distribution?

A process that enhances the distribution of medications by allowing IV fluids to enter tissues.

What role do epithelial cells play in medication distribution?

They create a barrier that small nonionic and lipophilic molecules can pass through easily.

What are the three routes of entry for larger hydrophilic and ionic molecules?

Pinocytosis, facilitated diffusion, and active transport.

What barriers must medications cross to reach tissues?

Blood-brain barrier, blood-placenta barrier, and blood-testes barrier.

In which organs does blood pass freely through capillaries?

Kidney, thyroid, pancreas, lungs, and peritoneum.

What happens to medication molecules during plasma protein binding?

They temporarily attach to proteins in blood plasma.

How can plasma protein levels affect medication concentration?

Changes in plasma protein levels or introduction of another medication can alter concentration.

What is the effect of lipophilic medications in obese individuals?

They are sequestered in fat tissues, leading to slow release and prolonged effects.

What does volume of distribution indicate?

The extent to which a medication will spread within the body.

What is biotransformation in medication metabolism?

The process by which a medication becomes a metabolite.

What are the possible effects of biotransformation?

Inactive substances become active, active medications change forms, or are inactivated for easier elimination.

Where does biotransformation primarily occur?

In the liver.

What is the role of the P-450 system in medication metabolism?

It alters the chemical structure of medications to make them easier to eliminate.

What are the two patterns of medication elimination?

Zero-order elimination and first-order elimination.

What is half-life in the context of medication elimination?

The time needed for metabolism or elimination of 50% of a substance in plasma.

What factors can alter the half-life of a medication?

Disease states, changes in perfusion, and medication interactions.

How are medications administered to maintain constant levels in the body?

At doses and frequencies equal to the body's rate of elimination.

What are some routes through which smaller amounts of medication can be eliminated?

Lungs, stool, saliva, breast milk, and perspiration.

What is a common cause of medication errors in clinical settings?

Decisions based on memory in stressful, life-threatening situations.

What is a recommended practice to reduce medication errors?

Perform verbal read-back of orders and label syringes.

What are sympathomimetic drugs?

Drugs that have alpha or beta sympathetic properties.

What do beta agents do to the heart?

Increase the heart's rate, force, and automaticity.

What are the two groups of agents classified under sympathomimetic drugs?

Beta-1 adrenergic agonists and beta-2 adrenergic agonists.

What do beta adrenergic blockers do?

Prevent beta agents from exerting their full effects.