Pharmacology - Semester 1 - Test #2

Practice Flashcards

Why is the abbreviation "qd" considered error-prone and prohibited on official medical records?

It is easily misread as "qid" (four times daily) or "od" (right eye); healthcare providers must write out the word "daily" to prevent medication overdose or underdose.

What do the common administration route abbreviations PO, IM, IV, and Subcut signify?

PO: By mouth (per os) IM: Intramuscular IV: Intravenous Subcut: Subcutaneous (SQ or SC are older abbreviations that should be avoided).

What do the timing abbreviations ac, pc, PRN, STAT, bid, and tid indicate on a medication order?

ac: Before meals pc: After meals PRN: As needed STAT: Immediately (at once) bid: Twice daily tid: Three times daily.

What four essential components must be present in a complete and legally valid provider medication order?

1. Medication Name (full generic or brand name)
2. Dose (exact amount, strength, and unit)
3. Route (specific anatomical path of delivery)
4. Time & Frequency (exact administration schedule).

Under what specific clinical circumstance is a nurse permitted to accept a verbal or telephone medication order?

Only during urgent or true emergency situations; verbal orders must never be accepted when the prescriber is physically present because telephone and verbal orders carry substantial legal and safety risks.

What are the nurse's primary responsibilities during medication reconciliation upon patient admission?

Documenting all current medications the patient takes prior to care (home medications, over-the-counter drugs, and herbal supplements), recording the exact time of the last taken dose, identifying non-compliance, and contacting the outpatient pharmacy if records are unclear.

What are the core Seven Rights of Medication Administration?

1. Right Patient
2. Right Drug
3. Right Dose
4. Right Route
5. Right Time
6. Right Reason
7. Right Documentation.

What additional rights are included when expanding to the Ten Rights of Medication Administration?

8. Right Patient Education (explaining therapeutic actions and potential side effects)
9. Right to Refuse (honoring patient autonomy and documenting refusal)
10. Right Evaluation (reassessing response and checking for adverse effects).

What are the three verification stages of the 3 Label Checks performed during medication preparation and administration?

Stage 1 (Pull): Check the medication label against the MAR when retrieving it from storage or the automated dispensing cabinet. Stage 2 (Prep): Check the label against the MAR when opening, measuring, mixing, or drawing up the medication. Stage 3 (Bedside): Check the label against the MAR directly at the patient's bedside before administration, verifying with two patient identifiers.

What is the primary preparation rule regarding who draws up and administers a medication?

A nurse must only administer medications that they personally prepared; never administer medications drawn up or prepared by another individual to ensure chain-of-custody and personal verification.

What are the four tiers of the clinical medication administration Prioritization Hierarchy?

Level 01: Safety First (allergies, swallowing status, baseline vitals, lab values) Level 02: Lifesaving Medications (STAT orders, acute emergency pharmacotherapy) Level 03: Time-Sensitive Medications (narrow-window drugs, insulin, antibiotics) Level 04: Least to Most Invasive (oral routes prior to parenteral routes).

A nurse has orders for Metoprolol $20\,\text{mg}$ PO TID, Docusate $10\,\text{mg}$ PO daily, and Heparin $40,000\,\text{units}$ IV STAT for a pulmonary embolism. Which is administered first and why?

Heparin $40,000\,\text{units}$ IV STAT must be given first because it is an urgent Level 02 lifesaving intervention prescribed for an acute, life-threatening thromboembolic emergency.

What must the nurse assess prior to administering an oral medication to ensure safety?

Assess the patient's level of consciousness, swallowing and gag reflexes, position (head of bed elevated to at least $45^{\circ}$ to $90^{\circ}$), NPO status, and whether the drug must be administered with or without food.

What should the nurse do if a competent adult patient refuses a scheduled medication?

Explore and address the patient's concerns, explain the medication's intended therapeutic benefit and the potential risks of refusal, withhold the dose, document the refusal on the MAR, and notify the prescribing provider.

At what point in the workflow should medication administration documentation take place?

Immediately following administration at the bedside; never document a medication in advance or prior to actually witnessing the patient swallow or receive the dose.

How does Barcode Medication Administration (BCMA) technology safeguard patient safety?

It acts as a point-of-care verification system by scanning the patient's ID wristband and the drug barcode against the electronic MAR, verifying the right patient, drug, dose, route, and time before the dose can be confirmed.

What is Computerized Provider Order Entry (CPOE), and how does it prevent medication errors?

A digital prescribing interface where providers enter orders directly into the EHR; it eliminates illegible handwriting, alerts clinicians to drug interactions and duplicate therapies, and standardizes order syntax.

How does the Swiss Cheese Model conceptualize systemic healthcare errors?

Accidents occur when active human errors (front-line mistakes) and latent system weaknesses (poor staffing, faulty equipment, unclear labeling) align across multiple safety barriers, allowing the hazard to breach all defenses.

What is the primary purpose and philosophy of a Root Cause Analysis (RCA)?

A structured, post-incident investigation that focuses on uncovering system design vulnerabilities, process breakdowns, and latent conditions rather than assigning individual fault or punitive blame.

What landmark finding was published in the 1999 Institute of Medicine (IOM) report "To Err is Human"?

It revealed that preventable medical errors cause up to $98,000$ deaths annually in the United States and mandated a paradigm shift from punitive individual blame to system-level safety protocols.

What is the mission of Quality and Safety Education for Nurses (QSEN)?

To equip future nurses with core competencies across patient-centered care, teamwork, evidence-based practice, quality improvement, safety, and informatics, framed around Knowledge, Skills, and Attitudes (KSAs).

What is TeamSTEPPS, developed by the Agency for Healthcare Research and Quality (AHRQ)?

An evidence-based communication and teamwork curriculum designed to optimize situational monitoring, mutual support, clear leadership, and standardized communication (such as SBAR and huddles) in healthcare.

What are common barriers to error reporting in nursing, and how does a "Just Culture" address them?

Barriers include fear of punishment, complex reporting tools, and lack of feedback; a Just Culture creates psychological safety by distinguishing human error (console), at-risk behavior (coach), and reckless behavior (sanction).

What is the nurse's first priority action upon discovering that an incorrect medication or dose was administered?

Assess the patient immediately for adverse reactions, check baseline vital signs, and provide necessary clinical stabilization interventions before documenting or calling the provider.

Following patient assessment and stabilization after an adverse event or error, what are the next two required actions?

1. Promptly contact the prescribing healthcare provider with findings and receive new orders.
2. Complete an institutional incident/error report (which is kept separate from the patient's legal medical record).

How does a drug side effect differ clinically from an adverse drug event (ADE)?

A side effect is a known, foreseen, and expected secondary reaction occurring at normal therapeutic doses; an ADE is an unexpected, undesirable, or harmful consequence resulting from medication exposure.

What clinical criteria categorize an adverse drug event as a Serious Adverse Event?

Any reaction that causes patient death, hospitalization or prolongation of existing hospitalization, permanent disability or incapacity, a congenital anomaly, a life-threatening condition, or requires immediate intervention to avert permanent harm.

What is meant by a narrow or low therapeutic index (TI)?

The ratio between the toxic dose and the effective dose is very small; minor fluctuations in serum drug concentration can rapidly precipitate severe toxicity or subtherapeutic failure.

What specific cranial nerve toxicity and sensory deficit can occur with toxic blood levels of Vancomycin?

Permanent damage to cranial nerve VIII (8) resulting in ototoxicity (tinnitus, sensorineural hearing loss, and vestibular disturbance), in addition to nephrotoxicity.

What life-threatening organ toxicity is caused by acute acetaminophen overdose?

Severe hepatotoxicity resulting in acute liver necrosis and liver failure due to depletion of hepatic glutathione reserves.

What immunological process underlies an allergic drug reaction?

The immune system identifies the medication (or its metabolite) as an antigen and produces specific antibodies (typically IgE); subsequent exposure cross-links antibodies on mast cells, triggering massive histamine release.

Why is a secondary exposure to an allergenic medication significantly more dangerous than the primary exposure?

The initial exposure sensitizes the immune system by generating circulating antibodies; secondary exposure produces a rapid, escalated, and potentially catastrophic systemic release of chemical mediators.

What are the hallmark signs and symptoms of systemic anaphylaxis?

Bronchoconstriction, wheezing, dyspnea, stridor, angioedema of the lips, tongue, and pharynx, profound hypotension (vasodilation), tachycardia, urticaria, flushing, and vascular collapse.

What three medications form the core emergency pharmacotherapy protocol for anaphylaxis, and what are their mechanisms?

1. Epinephrine: Alpha-1 agonist to raise systemic vascular resistance and blood pressure; Beta-2 agonist to trigger bronchodilation.
2. Diphenhydramine: H1 receptor antagonist that blocks further histamine action.
3. Prednisone / Methylprednisolone: Systemic corticosteroid to suppress delayed-phase inflammation and reduce capillary permeability.

What defines an additive drug interaction ($1 + 1 = 2$)?

Two drugs with similar pharmacologic actions combine to produce an effect that equals the exact arithmetic sum of each drug administered alone (e.g., alcohol combined with opioids causing severe CNS depression).

What defines a synergistic drug interaction ($1 + 1 > 2$)?

Two medications interact such that their combined clinical effect is significantly greater than the sum of their individual effects (e.g., Aspirin combined with Warfarin causing catastrophic hemorrhage).

What defines an antagonistic drug interaction ($1 + 1 < 2$)?

One drug opposes or reduces the pharmacologic action of another drug, resulting in an overall clinical response that is less than expected (e.g., Naloxone reversing the effects of Morphine at opioid receptors).

Why must Tetracycline never be administered concurrently with milk or antacids?

Tetracycline chelates divalent cations (such as $Ca^{2+}$ in dairy or $Mg^{2+}/Al^{3+}$ in antacids) to form an insoluble chelate complex in the gastrointestinal tract that completely blocks medication absorption.

Why are patients prescribed Warfarin instructed to maintain steady, consistent intake of green leafy vegetables?

Green leafy vegetables contain high levels of Vitamin K, which directly acts as an antagonist against Warfarin's anticoagulant mechanism by promoting the synthesis of clotting factors II, VII, IX, and X.

How does grapefruit juice alter the pharmacokinetic metabolism of certain medications?

Grapefruit compounds inhibit the intestinal Cytochrome P450 3A4 (CYP3A4) enzyme system, drastically reducing first-pass metabolism and causing serum drug concentrations to surge into toxic ranges.

Why should patients taking Levodopa avoid consuming high-protein meals at the time of dose administration?

Dietary amino acids from proteins compete directly with Levodopa for transport across the intestinal wall and the blood-brain barrier, causing therapeutic failure and sudden "off" periods.

What age-related physiological alterations in geriatric patients impact drug absorption and distribution?

Decreased gastric motility and elevated gastric pH (more alkaline) impair absorption; decreased cardiac output, reduced total body water, and decreased serum albumin reduce distribution and increase free active drug levels.

Why do age-related declines in hepatic and renal clearance in older adults necessitate reduced medication dosages?

Decreased hepatic blood flow and microsomal enzyme activity slow metabolism, while decreased glomerular filtration rate (GFR) impairs excretion, leading to drug accumulation and prolonged elimination half-lives.

Why are neonates and young infants at exceptional risk for medication toxicity?

They have immature hepatic enzyme synthesis, a low glomerular filtration rate, higher total body water, a porous blood-brain barrier, and reduced plasma protein binding capabilities.

What is a teratogenic medication, and in which trimester is the developing embryo most susceptible to anatomical malformations?

A compound capable of causing permanent structural or functional birth defects; the first trimester (weeks $3$ to $8$, during organogenesis) carries the highest vulnerability.

What three detailed subsections replaced the FDA letter categories (A, B, C, D, X) under the Pregnancy and Lactation Labeling Rule (PLLR)?

8.1 Pregnancy (detailed risk summary, clinical considerations, registry data) 8.2 Lactation (drug concentration in human milk, effects on the infant, effects on milk supply) 8.3 Females and Males of Reproductive Potential (pregnancy testing, contraception, infertility risks).

What are the four foundational phases of pharmacokinetics represented by the acronym ADME?

1. Absorption: Movement of drug from site of administration into systemic circulation
2. Distribution: Dispersal of drug through body fluids and tissues
3. Metabolism (Biotransformation): Enzymatic conversion of drug into active or inactive metabolites
4. Excretion: Elimination of drug or metabolites from the body.

What is first-pass hepatic metabolism, and which administration routes bypass it?

The rapid hepatic metabolism and extraction of an orally ingested medication absorbed through the portal venous circulation before reaching systemic circulation; bypassed by IV, IM, Subcut, sublingual, buccal, transdermal, and inhaled routes.

What is medication bioavailability, and what is the bioavailability of an intravenous injection?

The percentage or fraction of the administered drug that reaches systemic circulation unchanged; an intravenous injection has a bioavailability of $100\%$ ($F = 1.0$).

What is the biological half-life ($t_{1/2}$) of a medication?

The time required for the total plasma concentration or amount of drug in the body to decrease by exactly $50\%$ ($0.5$) through elimination and metabolism processes.

A medication has a half-life of $6\,\text{hours}$ and a peak serum level of $80\,\mu\text{g/mL}$. How much remains after $18\,\text{hours}$?

$10\,\mu\text{g/mL}$. Three half-lives have elapsed ($18 / 6 = 3$): after $6\,\text{hours}$ it is $40\,\mu\text{g/mL}$, after $12\,\text{hours}$ it is $20\,\mu\text{g/mL}$, and after $18\,\text{hours}$ it is $10\,\mu\text{g/mL}$ ($12.5\%$ of original).

How many half-lives does it typically take for a regularly administered drug to reach steady-state plasma concentration?

Approximately $4$ to $5$ half-lives; similarly, it takes $4$ to $5$ half-lives to clear greater than $95\%$ of the medication from the body once discontinued.

On a pharmacokinetic concentration-time curve, what are the onset of action, peak level, and duration of action?

Onset: Time required for drug concentration to reach the minimum effective concentration (MEC) Peak: Time at which the drug achieves highest plasma concentration Duration: Length of time the plasma concentration stays at or above the MEC.

What is the Minimum Effective Concentration (MEC), and what occurs if serum drug concentration exceeds the upper therapeutic limit?

MEC is the lowest blood concentration necessary to elicit a therapeutic response; exceeding the upper therapeutic limit causes toxic plasma concentrations and serious adverse effects.

How does severe renal failure affect the pharmacokinetic excretion of renally cleared medications?

Reduced glomerular filtration slows excretion, dramatically extending the elimination half-life and causing dangerous medication accumulation unless the dosage or administration frequency is reduced.

How can alterations in urinary pH influence the rate of drug excretion?

Urine alkalinization promotes ionization and renal clearance of weak acids (such as aspirin/salicylates), whereas urine acidification accelerates the clearance of weak bases (such as amphetamines).

What is pharmacodynamics?

The study of the biochemical and physiological effects of medications on the body and their molecular mechanisms of action (what the drug does to the body).

What is the molecular difference between a full receptor agonist and a receptor antagonist?

An agonist binds to a receptor and induces structural changes that activate intrinsic cellular activity; an antagonist binds to the receptor without activating it, physically blocking endogenous ligands from binding.

What is a partial agonist, and how does it behave in the presence of a full agonist?

A drug that binds to receptor sites but produces only submaximal intrinsic activity; in the presence of a full agonist, it acts as a competitive antagonist by occupying receptors and dampening the maximal response.

What is the distinction between drug affinity and drug selectivity?

Affinity refers to the binding strength between a drug and its specific receptor site; selectivity is the extent to which a drug acts on a single target receptor subtype relative to non-target receptors.

In pharmacodynamics, what do $ED_{50}$, $TD_{50}$, and $LD_{50}$ represent on a population dose-response curve?

$ED_{50}$: Median effective dose producing therapeutic response in $50\%$ of individuals. $TD_{50}$: Median toxic dose producing toxicity in $50\%$ of individuals. $LD_{50}$: Median lethal dose resulting in death in $50\%$ of tested animal subjects.

What is the mathematical formula for the Therapeutic Index (TI) in preclinical animal studies?

$\text{Therapeutic Index} = \frac{LD_{50}}{ED_{50}}$; a higher numerical value indicates a broader, safer margin of clinical safety.

How does target receptor down-regulation explain pharmacodynamic drug tolerance?

Chronic overstimulation by an agonist prompts target cells to internalize or degrade surface receptors; fewer functioning receptors require higher drug concentrations to achieve the initial therapeutic response.

Why does abrupt cessation of a chronically administered receptor agonist trigger severe withdrawal symptoms?

Receptors have been down-regulated; when the exogenous drug is suddenly removed, the remaining low-density receptors are inadequate to maintain baseline homeostasis under normal levels of endogenous ligands.

What is the difference between pharmacogenetics (PGx) and pharmacogenomics?

Pharmacogenetics focuses on the relationship between single-gene variations and individual drug metabolism/response; pharmacogenomics investigates the entire genome to study how multi-gene networks dictate drug behavior.

What role does the hepatic Cytochrome P450 (CYP) enzyme system play in drug metabolism?

A superfamily of liver microsomal enzymes (e.g., CYP2D6, CYP3A4, CYP2C19) that catalyze Phase I oxidation, reduction, and hydrolysis reactions to clear drugs or convert prodrugs into active forms.

What are the four metabolizer phenotypes categorized in pharmacogenomics?

1. Poor Metabolizer: Little to no enzyme function; slow clearance or inability to activate prodrugs
2. Intermediate Metabolizer: Reduced enzyme activity
3. Normal (Extensive) Metabolizer: Expected standard metabolic rate
4. Ultrarapid Metabolizer: Multiple gene duplications leading to exceptionally rapid drug metabolism.

How does a prodrug differ from an active drug with respect to Cytochrome P450 metabolism?

An active drug is administered in an active therapeutic state and inactivated by metabolism; a prodrug is administered as an inactive compound that requires enzymatic cleavage by CYP enzymes to yield the active therapeutic molecule.

A client is identified as a CYP2D6 poor metabolizer and is prescribed Codeine. What clinical outcome does the nurse anticipate and why?

The client will experience zero or minimal pain relief because Codeine is an inactive prodrug that requires bioactivation by CYP2D6 into active morphine; an alternative non-CYP2D6 analgesic must be requested.

What clinical risk occurs if a CYP2D6 ultrarapid metabolizer is prescribed standard therapeutic doses of Codeine?

Rapid, exaggerated conversion of Codeine into active morphine leads to toxic serum opioid levels, severe central nervous system depression, respiratory arrest, and death.

What ethical and autonomy challenges accompany clinical pharmacogenomic testing?

Protecting genetic privacy and avoiding health insurance discrimination, ensuring rigorous informed consent, managing patient anxiety regarding unexpected disease propensities, and addressing healthcare access inequities.

What are the primary operational limitations preventing routine implementation of pharmacogenomic testing?

High testing costs, variable third-party insurance reimbursement, prolonged laboratory turnaround times that delay acute therapy, and insufficient clinician education in interpreting genomic reports.

What is the mandatory clinical rule regarding leading zeros and trailing zeros in healthcare documentation?

Always use a leading zero before a decimal point (write $0.5\,\text{mg}$, never $.5\,\text{mg}$) to prevent ten-fold overdoses; never use a trailing zero after a decimal (write $5\,\text{mg}$, never $5.0\,\text{mg}$).

How many milligrams ($\text{mg}$) are in $1\,\text{g}$, and how many micrograms ($\mu\text{g}$ or $\text{mcg}$) are in $1\,\text{mg}$?

$1\,\text{g} = 1,000\,\text{mg}$$1\,\text{mg} = 1,000\,\mu\text{g}$ (or $\text{mcg}$).

How many milliliters ($\text{mL}$) are contained in $1\,\text{teaspoon (tsp)}$ and $1\,\text{tablespoon (tbsp)}$?

$1\,\text{teaspoon (tsp)} = 5\,\text{mL}$$1\,\text{tablespoon (tbsp)} = 15\,\text{mL}$ ($3\,\text{teaspoons}$).

How many milliliters ($\text{mL}$) are contained in $1\,\text{fluid ounce (oz)}$?

$1\,\text{fluid ounce (oz)} = 30\,\text{mL}$.

Calculation: A provider orders Cephalexin $500\,\text{mg}$ PO every $6\,\text{hours}$. Available is a liquid suspension of $250\,\text{mg}/5\,\text{mL}$. How many $\text{mL}$ should the nurse administer?

$10\,\text{mL}$. Formula: $\frac{\text{Desired}}{\text{Have}} \times \text{Volume} = \frac{500\,\text{mg}}{250\,\text{mg}} \times 5\,\text{mL} = 2 \times 5\,\text{mL} = 10\,\text{mL}$.

Calculation: A patient weighing $154\,\text{lb}$ is prescribed a medication at $2\,\text{mg/kg}$. What is the appropriate single dose?

$140\,\text{mg}$. Step 1: Convert weight: $154\,\text{lb} / 2.2 = 70\,\text{kg}$. Step 2: Calculate dose: $70\,\text{kg} \times 2\,\text{mg/kg} = 140\,\text{mg}$.

What is the teach-back method, and why is it superior to closed-ended confirmation questions?

An interactive communication technique where the nurse asks the patient to explain or demonstrate the instructions in their own words; it directly verifies comprehension, uncovers misunderstandings, and respects low health literacy.

What discharge instructions should a nurse provide to an outpatient starting an opioid or sedative-hypnotic medication?

Avoid operating heavy machinery or driving, avoid concurrent use of alcohol or OTC sedatives, rise slowly from sitting positions to prevent orthostatic falls, take with food if nausea occurs, and store in a secure, locked location.

How does the nursing process (ADPIE) apply when a client exhibits vital sign abnormalities prior to scheduled medication administration?

Assessment comes before intervention: assess vital signs and clinical status, hold the medication if parameters are violated (e.g., pulse $< 60\,\text{beats/min}$ for digoxin/beta-blockers), document the rationale, and notify the provider.