Pharmacology and Nursing: Drug Types, Administration, and Safety

Pharmacology

Study of drugs and their effects on living organisms

Interdisciplinary nature of pharmacology

Collaboration between doctors, pharmacists, and nurses to improve patient care and medication safety

Importance of pharmacology in nursing

Allows safe administration, patient education, monitoring, and advocacy

Generic vs Brand name

Generic: chemical name, lowercase, cheaper (e.g., ibuprofen); Brand: company name (e.g., Advil)

Prescription vs OTC

Prescription: regulated, higher risk, requires provider; OTC: safe when used correctly, no prescription

Traditional drugs

Chemically made, regulated by FDA

Biologics

Derived from living organisms, includes antibodies and vaccines

Complementary/Alternative therapies

Includes herbal remedies and acupuncture, less regulated

Drug schedules

Drugs classified from I-VI based on abuse potential; I highest, VI includes OTC

Socioeconomic factors affect pharmacology

Patients may skip meds or hospital visits due to cost, transportation, insurance, or citizenship

Nursing process - Assessment

Collect patient history, allergies, meds, vitals, head-to-toe

Nursing process - Diagnosis

Identify problems, form nursing diagnosis

Nursing process - Outcome Identification

Set attainable goals with patient

Nursing process - Plan

Determine best course of action for drug therapy

Nursing process - Implementation

Educate patient about med use, side effects

Nursing process - Evaluation

Document response and outcomes, modify plan if needed

Clinical judgment - Recognize cues

Gather relevant information: vitals, labs, allergies, pain, patient status

Clinical judgment - Analyze cues

Interpret significance; assess if patient is stable for med

Clinical judgment - Prioritize hypothesis

Identify most critical problem (e.g., risk of hypotension)

Clinical judgment - Generate solutions

Consider options: hold med, adjust dose, contact provider

Clinical judgment - Take action

Implement chosen solution, document, continue monitoring

Clinical judgment - Evaluate outcomes

Assess if intervention improved patient safety or condition

Principles of drug administration

Safe, accurate, patient-centered; nurses are last check

Seven rights of drug administration

Right patient, drug, dose, route, time, reason, documentation

Nurse's role in patient education

Teach med use, side effects, adverse effects, what to report

Drug routes and effects

IV: fastest, inhalation: fast, IM: moderate, SC: slower, PO: slower, topical: slowest

Pharmacodynamics

What the drug does to the body

Pharmacokinetics

How the body processes the drug (ADME: Absorption, Distribution, Metabolism, Excretion)

Absorption

Depends on route, blood flow, surface area, lipid solubility

Distribution

Perfusion, protein binding, cell permeability, volume of distribution

Metabolism

Liver breaks down drugs; first-pass effect reduces oral drug bioavailability

Excretion

Mostly by kidneys: glomerular filtration, tubular reabsorption, secretion via urine, sweat, bile, lungs

Half-life

Time for half of the drug to be eliminated

Therapeutic window

Drug amount for minimum effect up to maximum safe dose

Therapeutic index

Measure of safety: effective dose vs toxic dose

Drug receptor interaction

Agonist activates receptor; antagonist blocks receptor

Peak level

Highest blood concentration after administration

Potency

Amount of drug needed for desired effect

Side effect

Expected effect

Adverse effect

Potentially harmful effect

Last line of defense in drug admin

Nurses

Drug diversion

Giving prescribed drug to someone else

HIPAA

Protects patient health information; share only as needed

ANA Code of Ethics

Safe drug administration: Respect, Commitment, Advocacy, Accountability, Duty, Safety

Benefit-risk ratio

Benefit: desired effect; Risk: potential harm; therapy should have benefits outweighing risks

Preventing medication errors

7 rights, check 3x, verify orders, patient identifiers, calculations, reduce distractions, use technology, educate, document, report

Abbreviations and meds errors

Can cause miscommunication and dosing mistakes; avoid unsafe abbreviations

IT in drug admin

Barcodes, electronic records, and devices increase safety and reduce errors

Homeostasis

Body maintains stable internal environment via feedback loops

Intracellular fluid

40% body fluid, high K+, moderate Cl-

Extracellular fluid

20% body fluid, high Na+ and Cl-, low K+

Osmolarity

Solute concentration in body fluids

Tonicity

Relative concentration of a solution compared to inside cells; affects water movement

Hypertonic

Cell loses water, shrinks

Hypotonic

Cell gains water, swells

Isotonic

No net water movement, cell stays same

Positive feedback loop

Amplifies change (e.g., oxytocin in labor)

Negative feedback loop

Counters change to maintain stability (e.g., bleeding, BP regulation)

Fluid volume deficit

Hypovolemia, dehydration, low BP, high pulse, dry mucous membranes

Fluid volume excess

Hypervolemia, edema, high BP, pulmonary edema

Sodium

Regulates ECF, nerve impulses

Potassium

Cardiac and muscle function

Calcium

Bone health, neurotransmission, blood clotting

Magnesium

Muscle/nerve function, arrhythmias risk

Nursing implications electrolytes

Oral rehydration, diuretics

IV solutions - types

Hypotonic, Isotonic, Hypertonic

Crystalloids

Fluid replacement (saline solutions)

Colloids

Volume expansion (protein solutions)

Vitamins

Water soluble: short-term storage; Fat soluble: stored long-term

Innate immunity

Non-specific, first defense (skin)

Adaptive immunity

Specific, remembers antigens

Active immunity

Body produces antibodies

Passive immunity

Temporary antibodies from another source

Glucocorticoids

Indications: inflammation, autoimmune, transplant; Action: suppress immune system; Adverse: high BG, infection, mood; Interactions: NSAIDs, vaccines

Azathioprine

Indications: transplant, autoimmune; Action: stop immune cell multiplication; Adverse: low blood cells, infection; Interactions: allopurinol, vaccines

Mycophenolate

Indications: transplant, autoimmune; Action: inhibit T & B cells; Adverse: GI upset, infection, hypertension; Interactions: antacids, vaccines

Infection pathophysiology

Microbes invade, multiply, damage tissue; body responds with inflammation

Infection manifestations

Redness, warmth, swelling, pain

Bacteriostatic

Drugs stop bacteria from reproducing

Bactericidal

Drugs kill bacteria

Antibiotic resistance

Some bacteria survive drug exposure; can be gram-positive or gram-negative

Penicillin

Indications: strep, pneumonia; Action: kills cell wall; Adverse: rash, diarrhea; Interactions: oral contraceptives

Amoxicillin

Indications: respiratory, UTI; Action: kills cell wall; Adverse: rash; Interactions: oral contraceptives, warfarin

Amoxicillin-Clavulanate

Indications: resistant infections; Action: kills bacteria + enzyme blocker; Adverse: diarrhea, nausea; Interactions: warfarin

Cephalexin

Indications: respiratory, skin, UTI; Action: inhibits cell wall; Adverse: allergic reaction, diarrhea; Interactions: alcohol, anticoagulants

Sulfamethoxazole/Trimethoprim

Indications: UTI, respiratory; Action: blocks folic acid; Adverse: rash, photosensitivity; Interactions: warfarin, sulfonylureas

Levofloxacin

Indications: respiratory, urinary, skin; Action: inhibits DNA replication; Adverse: tendon rupture, GI upset; Interactions: antacids, warfarin

Azithromycin

Indications: respiratory, STIs; Action: inhibits protein synthesis; Adverse: GI upset, QT prolongation; Interactions: warfarin, statins

Gentamicin

Indications: severe gram-negative; Action: inhibits protein synthesis; Adverse: nephrotoxicity, ototoxicity; Interactions: loop diuretics

Doxycycline

Indications: acne, respiratory, Lyme; Action: inhibits protein synthesis; Adverse: photosensitivity, teeth staining; Interactions: antacids, iron, contraceptives

Amphotericin B

Indications: systemic fungal; Action: binds membrane; Adverse: nephrotoxicity; Interactions: nephrotoxic drugs

Fluconazole

Indications: fungal infections; Action: inhibits membrane; Adverse: GI upset, liver toxicity; Interactions: warfarin, antidiabetics

Nystatin

Indications: oral/topical candida; Action: binds membrane; Adverse: local irritation; Interactions: minimal

Acyclovir

Indications: herpes/shingles; Action: inhibits viral DNA; Adverse: nephrotoxicity, headache; Interactions: nephrotoxic drugs

Tamiflu

Indications: influenza; Action: inhibits neuraminidase; Adverse: nausea, vomiting; Interactions: minimal

Antiretrovirals

Indications: HIV/AIDS; Action: inhibit viral replication; Adverse: GI upset, liver toxicity; Interactions: many drugs

Vancomycin

Indications: MRSA, gram-positive; Action: inhibits cell wall; Adverse: nephrotoxicity, ototoxicity, Red-man syndrome; Interactions: nephrotoxic drugs

Nursing implications anti-infectives

Check labs, prevent infection, give drugs safely, monitor side effects, support patient

Client education anti-infectives

Take full course, report reactions, prevent infection, manage side effects, follow labs

Cancer cell characteristics

Uncontrolled growth, tumor formation, metastasis