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Pharmacology

Pharmacology Essentials

Educational Use Only. This app is not intended to replace instructor guidance, institutional policies, clinical judgment, or professional medical training.

Overview

Pharmacology is heavily tested on NCLEX. Focus on drug classifications, mechanisms, side effects, nursing considerations, and patient teaching. Master high-alert medications, antidotes, and drug interactions.

Key Concepts

  • 1

    Rights of medication administration: right patient, drug, dose, route, time, documentation, reason, response

  • 2

    High-alert medications: insulin, heparin/warfarin, opioids, chemotherapy, concentrated electrolytes

  • 3

    Antidotes: Naloxone (opioids), Flumazenil (benzodiazepines), Protamine (heparin), Vitamin K (warfarin), Acetylcysteine (acetaminophen)

  • 4

    Therapeutic index: narrow index drugs (digoxin, lithium, warfarin) require regular blood level monitoring

  • 5

    Drug interactions: CYP450 enzyme inhibitors/inducers affect metabolism of many drugs

  • 6

    Pregnancy categories: A (safe) through X (contraindicated); most drugs are category C

  • 7

    Time-critical medications: antibiotics, anticoagulants, insulin, anti-seizure, immunosuppressants

Nursing Interventions

  • Verify medication orders using the 8 rights before every administration

  • Check patient allergies and assess for cross-sensitivities before giving any drug

  • Monitor therapeutic drug levels for narrow-index medications (digoxin 0.5-2 ng/mL, lithium 0.6-1.2 mEq/L)

  • Assess renal and hepatic function before administering drugs metabolized by these organs

  • Use two patient identifiers before administration; never administer medication prepared by another nurse

  • Document immediately after administration, never before

  • Monitor for adverse effects and drug interactions; report to provider and document

Critical Red Flags

  • Anaphylaxis: urticaria, bronchospasm, hypotension within minutes of administration

  • Digoxin toxicity: nausea, vomiting, visual disturbances (yellow-green halos), bradycardia

  • Bleeding with anticoagulants: gums, urine, stool, unusual bruising

  • Hypoglycemia with insulin: sweating, tremors, confusion, tachycardia

  • Serotonin syndrome: fever, agitation, tremors, clonus, hyperreflexia with SSRIs

  • NMS: muscle rigidity, fever, altered mental status with antipsychotics

Key Lab Values

Digoxin therapeutic: 0.5-2.0 ng/mL (toxic >2.0)

Lithium therapeutic: 0.6-1.2 mEq/L (toxic >1.5)

INR therapeutic for warfarin: 2.0-3.0 (mechanical valve 2.5-3.5)

Acetaminophen toxic: >150 mcg/mL at 4 hours post-ingestion

Peak/trough levels for vancomycin: trough 10-20 mcg/mL

Patient Teaching

  • Take medications exactly as prescribed; do not stop or change dose without consulting provider

  • Keep a current list of all medications including OTC, supplements, and herbal products

  • Report side effects immediately, especially rash, difficulty breathing, or severe GI symptoms

  • Do not share medications with others or take expired medications

  • Store medications safely, away from children, heat, and moisture

  • Ask questions about new medications: what it's for, how to take it, what to expect

Educational Use Only — Not a substitute for professional training.