Pharmacology Comprehensive Review (Expanded)

Section 1: Nursing Process & Medication Administration

Summary: The nursing process (ADPIE) is fundamental to safe medication administration. Nurses also use the “Five Rights” to ensure proper delivery of medications and reduce errors.

Detailed Explanation

The Nursing Process consists of:

The Five Rights of medication administration are:

• Right Patient
• Right Medication
• Right Dose
• Right Time
• Right Route

Section 2: Types of Provider Orders

Summary: Provider orders can be categorized by how often and when they are given. Nurses must identify the correct type and clarify incomplete or confusing orders.

Detailed Explanation

Nursing Tip: If an order is missing dose, time, or route, the nurse must clarify before administering the medication.

Section 3: Pharmacokinetics

Summary: Pharmacokinetics refers to how the body handles drugs through Absorption, Distribution, Metabolism, and Excretion (ADME). The half-life is how long it takes for the drug’s concentration to decrease by 50%.

Detailed Explanation

Half-Life: If a drug’s half-life is 4 hours, then in 4 hours, only half of the active drug remains in the body. This concept helps determine dosing frequency.

Section 4: Therapeutic vs. Adverse Effects

Summary: Therapeutic effect is the drug’s intended goal. Side effects are mild/expected, while adverse effects are harmful and may lead to dose adjustments or discontinuation.

Detailed Explanation

• Therapeutic Effect: The reason the medication is prescribed (e.g., lowering BP, reducing pain).
• Side Effect: Known, often manageable effect (e.g., drowsiness with antihistamines).
• Adverse Effect: Harmful or unexpected effect requiring prompt attention (e.g., severe allergic reaction).
• Narrow Therapeutic Index: Drugs that have a small margin between therapeutic and toxic levels (e.g., warfarin). Close monitoring is required.

Section 5: Over-The-Counter (OTC) Medications

Summary: OTC meds are deemed safe at standard doses but can still pose risks (mask underlying conditions, cause interactions). Common examples include NSAIDs, acetaminophen, cough/cold meds, and antacids.

Detailed Explanation

• Masking Symptoms: Patients may treat heartburn with OTC PPIs or antacids without addressing a possible ulcer or GERD.
• Interactions: OTC meds (like calcium-containing antacids) can bind to antibiotics, reducing absorption.
• Patient Education: Remind patients to disclose all OTC use during assessment.

Section 6: Medication Safety Highlights

Summary: Key strategies to prevent administration errors and reduce infection risk.

Detailed Explanation

• Allergy Checks: Always re-check allergies even if documented (patients might recall new info).
• Hand Hygiene: Use soap and water or sanitizer before preparing/administering meds.
• Label Reading: Confirm drug name, dosage, expiration, and storage instructions.
• Never Administer Unlabeled Drugs: If you don’t know what’s in a syringe, do not give it.

Section 7: Dosage Calculation & 24-hour Time

Summary: Be comfortable with basic math for dosing (e.g., mg/kg, mg per dose, mL/hr) and 24-hour clock notation for accurate scheduling.

Detailed Explanation

Common calculation formula:

24-hour Time (Military Time):

Section 8: Exam-Specific Pointers

Summary: Quick tips for final prep on foundational content from Modules 1 & 2.

Detailed Explanation

• Review past exams/quizzes: Identify common pitfalls or high-miss questions.
• Nursing Process in Scenarios: Usually assess first, then diagnose, plan, implement, evaluate.
• Terminology: Distinguish side effect (mild, expected) vs. adverse effect (serious, harmful) vs. therapeutic effect (goal).
• Dosage Calculations: Practice thoroughly to avoid dosage errors.
• Know Trade vs. Generic: Familiarize yourself with both names to avoid confusion.

Section 1: Overview of Toxicity

Summary: Certain drugs damage specific organs: Hepatotoxicity (liver), Nephrotoxicity (kidneys), Ototoxicity (ears). Lab monitoring (e.g., creatinine for kidney function) is crucial.

Detailed Explanation

• Hepatotoxicity (Liver): Elevated liver enzymes (AST, ALT), jaundice, and caution with heavy alcohol use or pre-existing liver disease.
• Nephrotoxicity (Kidneys): Elevated creatinine/BUN, reduced urine output (<30 mL/hr). Assess fluid/electrolyte balance carefully.
• Ototoxicity (Ears): Hearing changes, tinnitus, sometimes dizziness. Common with aminoglycoside antibiotics, high-dose loop diuretics.

Section 2: Over-the-Counter (OTC) Pain Medications

Summary: Aspirin & NSAIDs reduce pain, fever, inflammation but can increase GI bleed risk. Acetaminophen lacks anti-inflammatory properties but can be hepatotoxic at high doses.

Detailed Explanation

Section 3: Opioid Analgesics

Summary: Opioids treat moderate-severe pain. Primary concern is respiratory depression, plus constipation, sedation. Antidote: Naloxone.

Detailed Explanation

• Monitor Respirations: If <12 breaths/min, consider holding the dose or contacting provider.
• Constipation: Opioids slow GI motility; prophylactic stool softeners/fiber recommended.
• Orthostatic Hypotension: Encourage slow position changes; risk of falls.
• Naloxone: Reverse opioid overdose. Must monitor rebound pain and withdrawal symptoms after administration.

Section 4: Opioid Analgesics (Detailed)

Summary: Additional points on dosing, sedation levels, and synergy with other CNS depressants.

Detailed Explanation

• Dosing Principle: “Start low and go slow,” especially in opioid-naïve or elderly patients.
• Sedation Scale: Some facilities use sedation scales to monitor for early signs of overdose (e.g., RASS score).
• Synergy with CNS Depressants: Combining with benzodiazepines or alcohol magnifies sedation and respiratory depression.

Section 5: Combining CNS Depressants

Summary: Muscle relaxants, benzodiazepines, barbiturates, and alcohol all depress the CNS. When combined, sedation and respiratory depression drastically increase.

Detailed Explanation

• Monitor Vitals & Sedation: Check level of consciousness, RR, blood pressure.
• Falls Risk: Grogginess, dizziness, or confusion can lead to accidents.
• Patient Education: Absolutely no alcohol while on multiple CNS depressants.

Section 6: Benzodiazepines & Barbiturates

Summary: Both are CNS depressants used for anxiety, insomnia, seizures. Benzodiazepines (e.g., lorazepam, diazepam) are generally safer than older barbiturates (phenobarbital).

Detailed Explanation

Section 7: Anti-Seizure Medications

Summary: Older meds (e.g., phenytoin, phenobarbital) need blood level checks (narrow index). Newer meds often have fewer side effects. Consistency is key—abrupt stoppage can cause seizures.

Detailed Explanation

• Therapeutic Drug Levels: Phenytoin typical range ~10–20 µg/mL; levels <10 might cause seizures, >20 risk toxicity.
• Side Effects: Gingival hyperplasia (phenytoin), sedation, ataxia.
• Adherence: Noncompliance is a common reason for breakthrough seizures.

Section 8: Signs of Over-Sedation & Overdose

Summary: Profound drowsiness, confusion, pinpoint pupils (for opioids), severe hypotension, or respiratory depression indicate possible overdose.

Detailed Explanation

• Overdose Signs: RR < 8/min, cyanosis, unresponsiveness, extreme lethargy.
• Immediate Actions: Check ABCs, give naloxone or flumazenil if appropriate, call for help.
• Monitoring Post-Reversal: Watch for rebound pain (opioids) or seizure risk (benzos), and re-sedation once antidote wears off.

Section 1: Antacids

Summary: Antacids neutralize existing stomach acid. They do NOT prevent acid production. Common examples: Tums (calcium carbonate), Rolaids, Mylanta. May affect absorption of other meds.

Detailed Explanation

• Frequent Dosing: Because they only neutralize current acid, repeated doses are often needed.
• Interactions: Can bind with certain antibiotics (e.g., tetracycline), reducing absorption.
• Watch for Overuse: High-dose magnesium hydroxide can cause diarrhea; aluminum-based can cause constipation.

Section 2: H2 Antagonists & PPIs

Summary: H2 blockers (e.g., famotidine) reduce acid secretion (~70%). PPIs (e.g., omeprazole) nearly block all acid (~100%) but have long-term risks (osteoporosis).

Detailed Explanation

Section 3: Laxatives Overview

Summary: There are multiple laxative categories—stimulant, osmotic, bulk-forming, and lubricant/stool softeners—each with different mechanisms and considerations.

Detailed Explanation

Section 4: GI “Protectant” (Sucralfate)

Summary: Sucralfate forms a protective barrier over ulcers to allow healing. Usually taken 6-8 weeks for full effect.

Detailed Explanation

• Mechanism: Sucralfate adheres to ulcer sites and shields them from acid and pepsin.
• Timing: Take on an empty stomach; avoid taking with antacids within 30 minutes.
• Combination Therapy: Often used alongside H2 blockers or PPIs to promote ulcer healing.

Section 5: Bowel Prep & Lactulose

Summary: Golytely is a strong osmotic solution used before colonoscopy to clear the bowel. Lactulose is used in liver patients to reduce ammonia.

Detailed Explanation

• Golytely (Bowel Prep): Large-volume osmotic solution; “clear stool” output means the bowel is adequately cleansed.
• Lactulose: Also an osmotic; traps ammonia in the colon, aiding excretion for patients with hepatic encephalopathy.
• Monitor Fluid & Electrolytes: Massive fluid shifts can lead to dehydration or imbalance.

Section 6: Metoclopramide (Reglan)

Summary: Increases GI motility, helping with delayed gastric emptying (gastroparesis) and reducing reflux/nausea.

Detailed Explanation

• Upper GI Motility: Moves stomach contents into intestines, alleviating nausea due to stasis.
• Diabetic Gastroparesis: Commonly prescribed to help with slow emptying in diabetics.
• Side Effects: Risk of extrapyramidal symptoms (e.g., involuntary muscle movements), sedation.

Section 7: Antiemetics (Ondansetron)

Summary: Ondansetron (Zofran) blocks serotonin receptors in the chemoreceptor trigger zone (CTZ), used for nausea/vomiting (post-op, chemotherapy).

Detailed Explanation

• 5-HT3 Antagonist: Prevents serotonin from activating the vomiting center.
• Uses: Pre-chemotherapy, post-op, general anti-nausea.
• Side Effects: Headache, dizziness, possible QT prolongation at high doses.

Section 8: Key Nursing Points & Final Tips (GI)

Summary: Address root causes (ulcers, GERD, motility) rather than just masking with OTC meds. Consider side effects, drug interactions, and correct usage.

Detailed Explanation

• Antacids: Short-term relief but may interfere with other meds. Don’t rely on them indefinitely without follow-up.
• H2 Blockers & PPIs: Very effective for acid-related issues, but long-term PPI use can lead to osteoporosis; weigh risks vs. benefits.
• Laxatives: Select carefully—bulk-forming is safest for regular use; stimulants and osmotics more potent but higher risk of dependency or dehydration.
• Antiemetics: Consider sedation, watch for any cardiac conduction changes (like QT prolongation).

Section 1: Thrombolytics vs. Antiplatelets vs. Anticoagulants

Summary: Thrombolytics dissolve existing clots; antiplatelets and anticoagulants prevent new clots. All carry bleeding risk.

Detailed Explanation

Section 2: Monitoring & Lab Values

Summary: Always monitor for bleeding. Each anticoagulant may require specific labs (PT/INR, aPTT) in addition to hemoglobin and platelets.

Detailed Explanation

• Hemoglobin & Platelets: Key for all blood thinners—if too low, risk of severe bleeding.
• Warfarin (Coumadin): Monitor PT/INR (therapeutic usually 2–3). Antidote = vitamin K.
• Heparin (unfractionated): Monitor aPTT (60–80s range). Antidote = protamine sulfate.
• LMWH (e.g., Enoxaparin): No routine aPTT needed, but watch platelets (risk of HIT).

Section 3: Diuretics & Antihypertensives

Summary: Different classes lower blood pressure or reduce fluid volume. Check kidney function, electrolytes, and heart rate.

Detailed Explanation

• Loop Diuretics (e.g., Furosemide): Potent, risk of hypokalemia & ototoxicity. Monitor electrolytes and hearing with IV push.
• ACE Inhibitors (e.g., Lisinopril): May cause cough, hyperkalemia, angioedema. Blocks Angiotensin I → II conversion.
• Beta Blockers (e.g., Metoprolol): Decrease HR/BP; hold if HR <60. Avoid nonselective in asthma/COPD.
• Calcium Channel Blockers (e.g., Diltiazem): Decrease HR/BP; also treat arrhythmias (e.g., atrial fibrillation). Watch for bradycardia.
• Nitrates (e.g., Nitroglycerin): Vasodilator for angina; main concern is hypotension.

Section 4: Additional Cardiovascular Adverse Effects

Summary: Besides hypotension & bradycardia, many CV meds can cause dizziness, arrhythmias, or fluid shifts.

Detailed Explanation

• Peripheral Edema: Some calcium channel blockers (like amlodipine) cause vasodilation leading to fluid accumulation in extremities.
• Rebound HTN: Stopping beta blockers or clonidine abruptly can spike BP.
• Arrhythmias: Over-suppression of conduction can lead to AV blocks or bradyarrhythmias.
• Daily Weights: Monitor fluid retention if suspect HF or side effects from meds.

Section 5: Patient Education & Safety (CV)

Summary: Emphasize medication adherence, lifestyle changes (diet, exercise), and the importance of lab follow-ups. Many CV meds require consistent intake at the same time each day.

Detailed Explanation

• Adherence: Inconsistent dosing leads to inadequate BP control or unstable anticoagulation.
• Lab Checks: Warfarin patients need periodic INR checks; some diuretics need K+ rechecks.
• Diet & Exercise: Helps reduce HTN and dyslipidemia; e.g., low-sodium diet, weight management, moderate physical activity if possible.
• Avoid Abrupt Discontinuation: Beta blockers, clonidine, or nitrates can cause rebound effects.

Section 6: Nitrates (Expanded)

Summary: Nitrates relieve angina by vasodilating, which reduces myocardial oxygen demand. Risk: hypotension, headache, possible reflex tachycardia.

Detailed Explanation

• Sublingual Nitroglycerin: Used for acute chest pain; up to 3 doses, 5 minutes apart. Call 911 if no relief after second dose.
• Storage: Keep in dark, airtight glass container; potency can degrade over time.
• Contraindications: Avoid erectile dysfunction meds (sildenafil) within 24–48 hrs— severe hypotension can occur.

Section 7: Overlap of Heparin & Warfarin

Summary: Warfarin can take 3–5 days to become therapeutic, so heparin or LMWH is often overlapped until INR is in range.

Detailed Explanation

• Bridge Therapy: Heparin/LMWH started first (immediate effect), warfarin initiated concurrently. Heparin stopped once INR 2–3 for at least 24 hours.
• Lab Monitoring: During bridging, watch aPTT or anti-Xa (for heparin) and PT/INR (for warfarin).
• Patient Education: Emphasize consistent intake of vitamin K (leafy greens) to avoid INR swings.

Section 8: Final Reminders (Cardiovascular)

Summary: Bleeding is the biggest risk with anticoagulants/thrombolytics; watch for hypotension or arrhythmias with antihypertensives. Patient safety and monitoring labs/vitals are key to preventing complications.

Detailed Explanation

• Thrombolytics: Strict time window for stroke/MI. High bleed risk; monitor neuro status closely.
• Antiplatelets & Anticoagulants: Bleeding assessment (skin, urine, stool, mental status changes) is paramount.
• Diuretics & Antihypertensives: Risk of orthostatic hypotension—advise slow position changes.
• Nitrates: Recheck vital signs often; treat headaches supportively.
• Goal: Achieve stable cardiovascular function with minimal side effects and optimal patient compliance.