NURS 208: TOPIC 8 - PHARMACOTHERAPEUTICS

What is a drug?

A chemical that affects the physiologic processes of a living organism

What is pharmacotherapeutics?

The treatment of pathologic conditions through the use of drugs

What is pharmacodynamics?

The study of the biochemical and physiologic interactions of drugs at their sites of activity and the effect of the drug on the body

What is pharmacokinetics?

The study of what happens to a drug from administration until the parent drug and metabolites leave the body, including absorption, distribution, metabolism, and excretion

What is drug classification?

The description of the physiologic reactions of the body to a drug, therapeutic or toxic, showing how the body as a whole is affected.

• Example: NSAIDs like ibuprofen (generic) also known as Advil (brand).

What is a contraindication?

A condition or factor that makes the use of a drug improper or unsafe

What is half-life?

The time required for half of an administered dose of a drug to be eliminated or for the drug’s blood level to decrease by 50%

What is an adverse effect?

Any undesirable occurrence related to administering or failing to administer a prescribed medication.

• Example: metoprolol is a beta-blocker that lowers heart rate (therapeutic effect) but may cause hypotension and cough (adverse effects).

What is the RN’s role in drug therapy?

To use the nursing process to guide drug therapy, ensure the medication is appropriate for the patient, verify correct transcription, administer it properly, monitor effects, and document outcomes.

If a nurse administers a drug, who is responsible for it?

The nurse.

Who is responsible for prescribing and who is responsible for dispensing medications?

Providers prescribe medications, and pharmacists dispense them.

How can nurses help prevent medication errors?

By following the Nine Rights of Drug Administration and knowing usual dosage ranges and routes for each medication.

What is one major set of guidelines nurses use to prevent medication errors?

The Nine Rights of Drug Administration.

Why must nurses know usual dosage ranges and routes?

To identify unsafe orders and prevent errors before administering medication.

What are key components of patient teaching related to medications?

Educating patients on how to properly take their medicine and promoting adherence.

What is an example of promoting medication adherence?

Ensuring a patient understands the importance of consistently taking BP medication.

What is a nursing consideration related to drugs that may cause hypotension?

Risk for falls.

What are the 9 rights of drug administration?

Right: drug, dose, time, route, patient, documentation, reason, response, to refuse

Right drug?

Correct medication ordered

Right dose?

Amount matches order and safe range

Right time?

Correct frequency and timing

Right route?

Correct method (oral, IV, etc.)

Right patient?

Identify using two identifiers

Right documentation?

Chart immediately after giving

Right reason?

Medication matches patient’s condition

Right response?

Patient shows expected effect

Right to refuse?

Patient may decline; document & notify provider if needed

What are time-critical medications?

Medications that can cause harm or reduced pharmacologic effect if given more than 30 minutes before or after the scheduled time.

What are examples of time-critical medications?

Insulin, antibiotics, anticoagulants like heparin, pain medications, antiarrhythmics.

What are non-time-critical medications?

Medications that can be given 1–2 hours early or late without causing harm or reduced effect.

What types of medications are usually non-time-critical?

Medications given for maintenance, comfort, or general health.

What are examples of non-time-critical medications?

Multivitamins, supplements, antihypertensives, stool softeners, proton-pump inhibitors (reduces stomach acid/GERD), maintenance psychological medications.

What are high-alert medications?

Drugs with an increased risk of causing significant harm if administered in error.

What do high-alert medications require before administration?

Heightened attention and verification using the 9 rights of medication administration and/or another nurse.

Which medications are considered high-alert?

Insulin, opiates, narcotics, IV heparin, and injectable potassium chloride.

What strategy helps reduce the risk of harm with high-alert medications?

Manual independent double checks with two nurses verifying the same information before administration.

What must you do when a provider gives any order?

Correctly interpret the order.

What must you always do when receiving a verbal order from a provider?

Read it back to the provider; document it as RBVO (Read Back Verbal Order).

What pattern must every proper medication order follow?

Medication, dose, route, frequency, indication.

What is an example of a scheduled medication order?

Acetaminophen 650 mg PO BID.

What is an example of a PRN medication order?

Acetaminophen 1000 mg PO q6 hours PRN Moderate Pain (4–7).

What is required for every PRN medication?

An indication (what it is for).

Is “Acetaminophen 2 tablets PO TID” a valid medication order?

No. “Tablets” is not a dose. Acetaminophen comes in different strengths (325 mg or 500 mg), which is the concentration.

Is “Ibuprofen 400 mg q6 hours PRN moderate pain (4–6)” a valid medication order?

No. It is missing the route.

Is “Ibuprofen 600 mg PO q8 hours” a valid medication order?

Yes.

Why does the medication route matter?

It matters because the route affects pharmacokinetics, meaning how the drug moves through the body, including how quickly it starts working and when it reaches its peak concentration.

How does pharmacokinetics relate to medication routes?

Different routes change how fast a drug is absorbed, distributed, metabolized, and excreted, which changes how it behaves in the body.

What does ADME stand for?

Absorption, distribution, metabolism, and excretion.

How can changing the route affect a drug?

Changing the route can alter the drug’s entire pharmacokinetic profile, causing differences in onset, peak levels, and how long the medication lasts.

What is absorption in pharmacokinetics?

The passage of drug molecules into the blood after administration.

What does absorption describe in pharmacokinetics?

How quickly a drug enters the body.

What factors can alter drug absorption?

Skin permeability, peristalsis rate, route of administration, food intake, vomiting, and other factors.

How does skin permeability affect drug absorption?

Topical drugs are absorbed differently depending on age; for example, infants have more permeable skin than older adults.

How does peristalsis affect oral drug absorption?

Slow or fast peristalsis can change how quickly a drug is absorbed in the gastrointestinal tract.

What are some other factors that can affect drug absorption?

Route of administration, food intake, vomiting, and other physiological or external conditions.

What is the difference between enteral and parenteral absorption?

Enteral absorption goes through the GI tract, while parenteral absorption bypasses the GI tract and is delivered directly into systemic circulation.

Which routes are considered enteral?

Oral, sublingual (under the tongue), buccal (in the cheek), and rectal.

How is absorption achieved in enteral administration?

Through oral or gastric mucosa or the intestine into systemic circulation.

Which routes are considered parenteral?

Intravenous, intramuscular (injection in muscles), subcutaneous (injection in adipose tissue), intradermal (between layers of the skin, e.g., TB skin test), intra-arterial (directly into the artery), intrathecal (spinal cord, e.g., epidural), intrarticular (in the joints).

Name the parenteral route where medication is injected directly into a vein.

Intravenous.

Which parenteral route involves injecting medication into muscles?

Intramuscular.

Where is medication injected in the subcutaneous route?

Into the adipose tissue under the skin.

Where is medication administered in the intradermal route?

Between layers of the skin.

Give an example of intradermal administration.

TB skin test.

Which parenteral route delivers medication directly into an artery?

Intra-arterial.

Which parenteral route delivers medication into the spinal cord?

Intrathecal.

Give an example of intrathecal administration.

Epidural.

Where is medication administered in the intrarticular route?

Into the joints.

What is the topical route considered?

It is considered parenteral.

Which route of administration delivers medication fastest, directly into the bloodstream?

Intravenous (IV); example: IV pain medicine.

What is the intramuscular route of medication administration?

Intramuscular (IM); medication is injected into a muscle.

What is the subcutaneous route of medication administration?

Subcutaneous (Subcut); medication is injected under the skin.

What factors affect absorption for topical medications?

Absorption depends on the site; the thinner the skin, the faster the absorption.

Which route of administration is generally the slowest?

Oral (PO).

How does the form of oral medication affect absorption speed?

Liquid is fastest, followed by capsule, tablet, and extended release, which is slowest.

What is distribution in pharmacokinetics?

It is how drugs are transported from the area of absorption to the site where they exert their effect.

What factors can affect drug distribution?

Factors that affect distribution include the amount of protein available in the body, dehydration, heart function, body fluid levels, body fat/obesity, and the chemical makeup of the drug.

What is the body’s main protein form that affects drug distribution?

Albumin.

How does dehydration affect drug distribution?

It can reduce the volume of distribution, potentially increasing drug concentration in the blood.

How does heart function influence drug distribution?

Poor heart pumping can slow the delivery of drugs to tissues, affecting their effectiveness.

How does body fluid level affect drug distribution?

Higher fluid levels can dilute drugs, while low fluid levels can concentrate them; obesity can prolong drug effects due to drug storage in fat tissue.

How does the chemical makeup of a drug affect its distribution?

Whether a drug is water-soluble (hydrophilic) or lipid-soluble (hydrophobic) affects how easily it moves through the body and reaches its target.

What is metabolism in pharmacokinetics?

It is how drugs are changed by the body.

How are most drugs changed by the body?

Most drugs are changed from an active form to an inactive form.

What are drugs called that are changed from an inactive form to an active form?

Prodrugs.

Where are most drugs metabolized?

Most drugs are metabolized by the liver.

What in the liver is primarily responsible for metabolizing drugs?

Enzymes in the liver do most of the work required to alter a drug’s form.

What factors affect drug metabolism?

The health of the liver, the number of enzymes available, and the presence of other drugs using the same enzymes.

How does liver disease affect drug metabolism?

Cirrhosis prevents the liver from metabolizing drugs effectively, causing a toxic buildup in the body.

How does age affect drug metabolism?

Elderly patients metabolize drugs more slowly, so dosage or frequency may need adjustment.

Why is the rate at which a drug is metabolized important?

The speed of metabolism is used to calculate a drug’s half-life.

What is excretion in pharmacokinetics?

It refers to how drugs are removed (excreted) from the body.

Which organ is responsible for excreting most drugs?

The kidneys; drugs are primarily excreted in urine.

Besides the kidneys, how else can drugs be excreted from the body?

Through feces (biliary excretion) or sweat.

What factor related to kidney health affects drug excretion?

Kidney function; diseases that impair the kidneys can cause drugs to build up to toxic levels.

How does dehydration affect drug excretion?

It slows excretion due to low fluid volume, potentially leading to toxic drug buildup.

How is drug excretion related to a drug’s half-life?

The rate at which a drug is excreted helps determine its half-life.

How can drug excretion be used to benefit a patient?

Certain drugs are administered or dosed based on how they are excreted to optimize therapeutic effect and reduce toxicity.

How many different names does each drug have at minimum?

3

How can drugs be classified?

Drugs can be classified according to their chemical structure or their therapeutic use.