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Narrow vs Broad Spectrum Antibiotics

  • Narrow spectrum: Target specific bacteria types when exact pathogen is known

  • Reduce bacterial resistance risk and preserve normal flora

  • Broad spectrum: Target wide variety (gram positive and negative)

  • Used when bacteria not yet identified or in critical conditions awaiting lab results

Bactericidal vs Bacteriostatic

  • Bactericidal: Directly kill bacteria ("the killers")

  • Bacteriostatic: Prevent bacterial growth without direct killing

Antibiotic Selection Process

  • Identify causative agent through body fluid analysis (blood, urine, sputum)

  • Perform sensitivity tests to determine effective antibiotics

  • Consider infection location, patient age, allergies, and immune status

  • Testing methods: Gram stain (quick assessment) vs Culture (detailed, several days)

  • Disk diffusion test: Bacteria sensitive if no growth near antibiotic disc

Key Laboratory Values

  • MIC: Minimum concentration to stop bacterial growth

  • MBC: Minimum concentration to kill 99.9% of bacteria

Nursing Responsibilities

  • Collect specimens for culture testing

  • Prevent contamination during sample collection

  • Ensure accurate test results

Combination Therapy and ProphylaxisDrug Interactions

  • Potentiating: One drug enhances the other's effect

  • Antagonistic: Combined drugs less effective than separate use

  • Additive: Combined effect equals sum of individual effects

Prophylaxis Use

  • Preventive medication use to prevent infections before they occur

Major Antibiotic ClassesPenicillins

  • Mechanism: Bactericidal - disrupts bacterial cell wall

  • Side effects: Anaphylaxis, renal impairment, electrolyte imbalances (hyperkalemia >5 mEq/L, hypernatremia >145 mEq/L)

  • Drug interactions: Cannot mix with aminoglycosides in same IV (inactivates both drugs)

  • Administration: Give penicillin 1 hour before or after aminoglycosides using separate IV lines

  • Probenecid interaction: Delays penicillin excretion, can cause kidney impairment

Cephalosporins (Five Generations)

  • 1st generation: Effective against gram-positive bacteria

  • 2nd & 3rd generation: Effective against gram-negative bacteria

  • 4th generation: Effective against both gram-positive and gram-negative

  • 5th generation: Effective against multi-drug resistant organisms

  • Advantages: Better tissue penetration, longer half-lives, less frequent dosing improves compliance

  • Side effects: Bleeding (interferes with vitamin K), thrombophlebitis at IV site

  • Monitoring: Check IV site for swelling, redness, warmth, pain; rotate IV every 72 hours

  • C. diff risk: Can cause pseudomembranous colitis - monitor for diarrhea

Vancomycin

  • Uses: C. diff, staph, MRSA infections

  • Administration: IV (most common), PO, or suppository

  • Red Man Syndrome: Histamine release from rapid infusion causing flushing, rash, hypotension, tachycardia

  • Prevention: Infuse over 60-90 minutes, pre-medicate with antihistamines

  • Ototoxicity: Monitor for tinnitus, hearing loss, vertigo, ear pressure

Tetracyclines

  • Mechanism: Bacteriostatic, prevents protein synthesis

  • Uses: Acne, periodontal disease, STI treatment

  • Contraindications: Children and pregnant women (tooth discoloration, enamel hypoplasia)

  • Side effects: Photosensitivity, hepatotoxicity, reduces hormonal contraceptive effectiveness

Macrolides

  • Mechanism: Bacteriostatic (bactericidal at higher doses)

  • Unique risk: Prolonged QT intervals leading to cardiac dysrhythmias and potential sudden death

Aminoglycosides

  • Mechanism: Bactericidal, effective for gram-negative bacteria

  • Side effects: Ototoxicity, nephrotoxicity, neuromuscular blockade (muscle weakness)

  • Monitoring: Peak and trough levels required

    • Trough: Lowest concentration, measured before next dose

    • Peak: Highest concentration, measured 30 minutes after dose completion

General Monitoring and SafetyAllergy Assessment

  • Always ask about medication allergies before first dose

  • Monitor for reactions: Immediate (2-30 min), accelerated (1-72 hours), delayed (days-weeks)

Treatment Effectiveness

  • Post-treatment culture to confirm absence of microorganisms

  • Clinical improvement (fever resolution, clear lung sounds)

Patient Education

  • Complete entire course even if feeling better to prevent resistance

For STI treatment: abstain from intercourse until negative culture results

Tissue Injury & Inflammatory Response

  • Initial vasoconstriction occurs immediately after injury to minimize blood loss (temporary reaction)

  • Chemical mediators released: histamines, kinins, and prostaglandins - crucial for inflammatory response

  • Vasodilation follows - blood vessels widen, increasing blood flow to injured area

  • Classic inflammatory symptoms: redness (erythema), swelling (edema), pain from nerve stimulation, fever/heat

NSAIDs Classification & Examples

  • Propionic derivatives: ibuprofen, naproxen

  • Phenomates: mefenamic acid

  • Available OTC: salicylates, propionic acid derivatives

  • Prescription required: COX2 inhibitors, acetic acid derivatives, oxicams, phenomates

Mechanism of Action

  • COX enzymes: cyclooxygenase (COX1 & COX2) convert arachidonic acid to prostaglandins

  • COX1: Always active, protects stomach lining, helps platelet aggregation

  • COX2: Activated only during tissue injury, causes inflammation and pain

  • NSAIDs inhibit COX enzymes, preventing prostaglandin production (prostaglandin inhibitors)

Primary Effects

  • Antipyretic: reduces fever

  • Analgesic: pain relief

  • Anticoagulant: prevents blood clots (especially aspirin)

Specific Drug Categories

  • Salicylates (aspirin): pain, inflammation, fever, anticoagulant effects

  • Propionic acid derivatives: mild to moderate pain (1-6 on pain scale), inflammation, fever

  • Acetic acid derivatives: more effective for inflammation but significant GI side effects

  • COX2 inhibitors: second generation NSAIDs with better safety profile, target COX2 specifically

  • Oxicams: long-term use for osteoarthritis/rheumatoid arthritis, longer half-life (once daily)

  • Phenomates: especially effective for menstrual pain

Major Side EffectsGastrointestinal

  • Dyspepsia: heartburn, indigestion, abdominal pain, nausea

  • Long-term risks: stomach lining damage, GI bleeding, perforation (holes in stomach/intestines)

  • Bleeding signs to monitor: dark tarry stools, bleeding gums, petechiae, ecchymosis, purpura

  • Higher risk patients: older adults, smokers, alcohol users, pre-existing ulcers

  • Prevention: proton pump inhibitors or H2 receptor antagonists to reduce stomach acid

Kidney Effects

  • Impaired function: reduced urine output, fluid retention, weight gain, edema

  • Monitor: BUN and creatinine levels for kidney function

  • Mechanism: NSAIDs reduce blood flow to kidneys, worsening function and increasing kidney disease risk

Cardiovascular Risk

  • Non-aspirin NSAIDs increase heart attack and stroke risk

  • Prescribe at smallest effective dose

Special ConsiderationsMenstrual Pain (Dysmenorrhea)

  • Avoid aspirin for painful menstruation with heavy bleeding

  • Use acetaminophen 2 days before and during first 2 days of menstrual period

Aspirin-Specific Risks

  • Salicylism/Aspirin toxicity: early symptoms from overdose, can progress to electrolyte imbalances, coma, respiratory depression

  • Serum salicylate levels: >30 mg/dL mild toxicity, >50 mg/dL severe toxicity

  • Treatment: activated charcoal, possible hemodialysis

  • Reye's syndrome: rare but serious condition causing liver/brain swelling in children/adolescents recovering from viral infections (flu, chickenpox)

  • Reye's syndrome symptoms: persistent vomiting, lethargy, confusion \u2192 irritability, aggression, disorientation, seizures, loss of consciousness

  • Avoid aspirin in children/adolescents with viral infections

Drug Interactions & Precautions

  • Glucocorticoids: amplify stomach bleeding risk

  • Alcohol: increases stomach bleeding - limit/avoid consumption

  • Other NSAIDs: can negate heart protective effects of aspirin - space dosing apart

  • Herbal supplements: garlic and ginseng enhance bleeding risk

  • High-risk populations: older adults, smokers, certain health conditions (H. pylori, hypovolemia, asthma, bleeding disorders)

Specific Drug ConsiderationsKetorolac

  • Never use with advanced kidney disease

  • Maximum 5 days of treatment

  • Best for moderate to severe post-operative pain

  • Routes: IV, IM for rapid onset, then PO

Celecoxib (COX2 Inhibitor)

  • Caution with heart disease - increases heart attack and stroke risk

  • Last resort for pain management

IV Ibuprofen

  • Infuse over 30 minutes to minimize vascular irritation and hypotension

  • Ensure adequate hydration to preserve renal function

Aspirin Surgery Considerations

  • Discontinue 1 week before elective surgery unless prescribed for cardiovascular protection

Acetaminophen

  • IV form: Ofirmev

  • Mechanism: works in brain and spinal cord, blocks prostaglandin production, inhibits COX2

  • Side effects: nausea, vomiting, headaches, insomnia

  • Prolonged use: can affect liver function

Dosage Limits

  • Most clients: no more than 4 grams per day

  • Undernourished patients: no more than 3 grams per day

  • Alcohol consumers (3+ drinks/day): no more than 2 grams per day

Toxicity & Treatment

  • Medical emergency requiring ER treatment

  • Antidote: acetylcysteine (Mucomist) via duodenal tube or IV to prevent vomiting/aspiration

  • Monitor liver function: ALT, AST, bilirubin, alkaline phosphatase

Key Clinical Points

  • Ibuprofen and diabetes: can mask hypoglycemia symptoms - use with caution

  • Aspirin for prevention: low-dose (81mg) for stroke/heart attack prevention in high-risk patients

  • Pharmacokinetics: Study of how drugs move within the body from administration to elimination

  • Encompasses the complete "journey of medication" through four main stages

  • Addresses key questions: How does medication reach target areas? What happens after administration?

Stage 1: Absorption

  • Process: How medication enters the bloodstream

  • Routes: Enteral (digestive system), parenteral (injection), sublingual, inhalation, topical, subcutaneous

  • Key factors: Speed of absorption, strength (amount absorbed), and administration method all impact drug potency

Stage 2: Distribution

  • Process: Transportation of medication to different body parts via bloodstream

  • Circulation factor: Blood flow issues (e.g., heart disease) impede medication transport

  • Cell membrane permeability: Medications pass through barriers to reach exclusive areas like the brain

  • Plasma protein binding: Medications attach to proteins (albumin) for distribution - limited availability creates competition among multiple drugs ("musical chairs" effect)

Stage 3: Metabolism

  • Process: Chemical alteration of drugs, primarily in the liver

  • Purpose: Makes medication more water-soluble, less active, or inactive to facilitate excretion

  • Other metabolic sites: Lungs, intestines, bloodstream (liver remains primary)

Factors Influencing Metabolism

  • Age: Infants have immature digestive systems vs. elderly patients

  • Enzyme levels: Can accelerate or slow metabolism

  • First pass effect: Some drugs inactivated by liver on first pass - doctors may change route (PO to sublingual/injection) to avoid this

  • Shared metabolic pathways: Multiple medications compete for same metabolic processes

  • Nutrition: Poor diet lacks necessary ingredients for proper drug metabolism

Stage 4: Excretion

  • Process: Removal of drugs and metabolites from the body

  • Primary organ: Kidneys (main site for dumping medication remnants)

  • Secondary sites: Liver and other organ systems also contribute to excretion

Drug Half-Life

  • Dosing frequency depends on half-life: every 4-6 hours, 3x daily, or 1-2x daily based on drug's half-life

Pharmacodynamics Overview

  • Definition: Study of what a drug does in the body - how it produces both therapeutic and harmful side effects

Three Types of DrugsAgonist Drugs

  • Bind to receptor, activate it, produce full biological response

  • Analogy: Key that fully turns and opens the door

  • Example: Morphine - binds to opioid receptors in brain/spinal cord for full pain relief

Partial Agonist Drugs

  • Bind to receptor but produce weaker response than full agonist

  • Analogy: Key that partially opens the door

  • Example: Buprenorphine - provides milder pain relief effects

Antagonist Drugs

  • Bind to receptor but block activation by other substances

  • Analogy: Broken key that fits but doesn't turn

  • Example: Naloxone - antidote to opioid overdose, blocks opioid receptors and reverses morphine effects

Routes of AdministrationOral/Enteral Medications - Safety First

  • Do NOT give PO meds if patient:

    • Is vomiting

    • Has trouble swallowing

    • Is less alert

    • Has no gag reflex

  • Best position: High Fowler's (90 degrees) to help with swallowing

  • Food considerations: Medications that irritate stomach should be taken with food

  • Grapefruit juice warning: Can affect drug effectiveness - avoid with medications

  • Cannot crush: Enteric-coated or time-release tablets

Sublingual and Buccal Routes

  • Enter bloodstream directly, bypass liver and first-pass effect

  • Patient instructions: Keep tablet in place until dissolved, avoid eating/drinking for complete absorption

Nasal Administration

  • Use aseptic technique: Hand hygiene, clean gloves, alcohol cleaning

  • Review ATI for proper nasal drops and spray administration techniques

Rectal Suppositories

  • Position: Start supine, then turn to left side (Sims position) - takes advantage of natural colon curve

  • Post-insertion: Patient remains flat for 5 minutes to retain suppository and facilitate absorption

Vaginal Administration

  • Preparation: Perineal care to ensure clean area, may need lubrication

  • Insertion depths:

    • Suppositories: 3-4 inches deep in posterior vaginal wall

    • Creams/foams/jellies: 2-3 inches deep

  • Post-administration: Patient lies down for 5 minutes

Inhalers

  • Spacer benefits: Easier to use, more effective, increases lung delivery while decreasing throat deposition

  • Technique: Shake 5-6 times to mix medication, patient exhales completely, closes lips around spacer, then inhales

NG/G-Tubes

  • Preferred form: Liquid medications

  • If crushing needed: Only crush one medication at a time (not multiple together)

  • Special consideration: Sublingual drugs should still be given sublingually even with tubes present - maintains therapeutic effect

  • Administration: Check tube placement, use gravity flow (no plunger), flush after to clear remaining medication

Parenteral InjectionsBest Injection Sites

  • Ventrogluteal: Best for IM injections, especially >2cc volumes - away from major nerves/vessels

  • Vastus lateralis: Best for infants - largest thigh muscle

  • Deltoid: Adults, smaller muscle mass, limit to 1cc or 1ml

Injection Guidelines

  • Tuberculin syringe: For small volumes <0.5ml

  • Site rotation: Prevent tissue damage with repeated injections

  • Avoid injecting: Edematous, inflamed areas, or areas with moles/birthmarks

Injection Types and Angles

  • Intradermal: 10-15 degrees, for TB skin testing, do not massage site to avoid dispersing solution

  • Subcutaneous: For small, non-irritating, water-soluble drugs (insulin, heparin), use areas with good fat pads

  • Intramuscular: See angle chart

Needle Gauges

  • Higher number = smaller needle, lower number = bigger needle

  • 16 gauge: Trauma patients

  • 18 gauge: Surgery and blood administration

  • 22-24 gauge: Children, elderly, stable post-op patients

Z-Track Method

  • Used for: Medications that stain skin or are irritating (e.g., iron preparations)

  • Purpose: Prevents leakage into subcutaneous tissue, avoiding skin discoloration and irritation

Side Effects vs Adverse EffectsSide Effects

  • Expected, unintended but not necessarily harmful

  • Occur at therapeutic doses, mild and tolerable

  • Examples: Drowsiness from Benadryl, dry mouth, mild nausea

  • Physician may continue drug despite side effects

Adverse Effects

  • Unintended AND harmful/undesirable effects

  • Can occur at normal doses or from improper use/overdose

  • Range: Mild to severe (life-threatening)

  • Can be: Predictable or unpredictable (allergic/idiosyncratic reactions)

  • Examples: Acetaminophen liver damage, penicillin allergic reactions

Drug Interactions

  • Medications interact with: Other drugs, food, herbal remedies, supplements

  • Example: Grapefruit juice can cause potential interactions

Contraindications vs Precautions

  • Contraindications: STOP sign - medication should NOT be used because it can be harmful

  • Precautions: YELLOW caution sign - medication should be used with extra care and monitoring, not a definite no but proceed with caution

Common Side Effect ProfilesCNS Effects

  • CNS Depressants (e.g., opioids): Decreased brain activity \u2192 drowsiness, sedation

  • CNS Stimulants (e.g., ADHD meds): Increased alertness/activity \u2192 seizure risk warning

Cardiovascular Effects

  • Anti-hypertensives: Commonly cause orthostatic hypotension

Anticholinergic Effects

  • Blocks acetylcholine \u2192 dry mouth, blurred vision, constipation, increased heart rate, urinary retention, reduced sweating, photophobia

Other Effects

  • GI: Nausea, vomiting, stomach irritation

  • Hematological: Bone marrow suppression/depression affecting blood and blood-forming organsu

Drug Toxicity

  • Can be fatal when patients take excessive dosages or take medication too frequently

  • Acetaminophen example: causes liver damage in high amounts

Hepatotoxicity

  • Many medications processed in liver - impacts drug processing if liver damaged

Symptoms:

  • Fatigue, nausea, vomiting, loss of appetite

  • Right upper quadrant abdominal pain

  • Jaundice (yellowing of skin/eyes), dark urine, pale/clay-colored stool

  • Pruritus (itching), ascites (abdominal swelling)

Lab Tests:

  • ALT, AST, ALP, Bilirubin, Prothrombin time

Nephrotoxicity (Kidney Damage)Symptoms:

  • Fatigue, nausea, vomiting, loss of appetite

  • Oliguria (decreased urine output)

  • Fluid retention/swelling in legs, ankles, feet, face

  • Shortness of breath (fluid overload), hypertension

Lab Tests:

  • BUN, creatinine, electrolytes (potassium, sodium)

Hypersensitivity/Allergic Reactions

  • Immune response after exposure to substances like penicillin

  • Body creates antibodies; subsequent exposure triggers allergic reaction

Mild Symptoms:

  • Itching, rashes, watery eyes, sneezing

  • Inflammation of nose and sinuses

Severe: Anaphylaxis

  • Life-threatening reaction requiring immediate medical attention

  • Affects all body systems (vs angioedema affecting face/neck)

  • Initial signs: itching, redness, anxiety, weakness

  • Can lead to respiratory failure if untreated

Angioedema

  • Serious allergic reaction affecting deeper skin layers, blood vessels, subcutaneous tissue, mucous membranes

  • Primarily affects face, lips, neck

  • Medical emergency - throat swelling can block breathing

  • Stridor (high-pitched breathing sound) indicates airway compromise

Treatment:

  • Mild cases: antihistamines (diphenhydramine)

  • Moderate/severe cases: corticosteroids to reduce swelling

Drug Interactions

  • Combining drugs can increase/decrease therapeutic effects

  • Can increase/decrease side effects or lead to toxicity

  • Must warn patients about interactions with OTC drugs and herbal supplements

FDA Pregnancy Drug Categories

  • Category A: Safest - no risk shown in studies

  • Category B: Animal studies show no risk, limited human studies

  • Category C: Animal studies show adverse effects, no human studies

  • Category D: Evidence of human fetal risk, but benefits may outweigh risks

  • Category X: Proven risk in animals and humans - risk outweighs benefits