Pharmacology and Pain Management Essentials

Key Safety Pearls and General Corrections

• Butorphanol Correction: Butorphanol is NOT an NSAID. It is classified under agonist-antagonist opioids.

• NSAID Identification: Nonsteroidal anti-inflammatory drugs include aspirin, ibuprofen, naproxen, indomethacin, ketorolac, and celecoxib.

• NSAID Safety Risks: These medications can increase the risk for gastrointestinal (GI) bleeding, ulcers, kidney injury, fluid retention, and cardiovascular events.

• Acetaminophen Dosage: The maximum adult dose is generally $4,000\,mg/day$ from all sources combined.

• Opioid Safety: Opioids can cause serious respiratory depression. Naloxone is the specific reversal agent for opioid-related respiratory depression.

• Live Vaccine Contraindications: Live vaccines such as MMR (Measles, Mumps, Rubella) and varicella are contraindicated in situations involving severe immunocompromise and pregnancy.

Non-Opioid Analgesics

First-Generation NSAIDs

• Prototypes: Aspirin, Ibuprofen, Naproxen, Indomethacin, Ketorolac.

• Category/Class: Nonsteroidal anti-inflammatory drugs; COX-1 and COX-2 inhibitors.

• Purpose of Medication:

  • Treatment of mild to moderate pain.

  • Decrease inflammation.

  • Reduction of fever.

  • Aspirin specifically provides antiplatelet effects.

• Expected Pharmacological Action:

  • Inhibits Cyclooxygenase (COX) enzymes.

  • Decreases prostaglandin production.

  • Reduction in prostaglandins leads to decreased pain, fever, and inflammation.

  • Inhibition of COX-1 specifically increases the risk for gastric bleeding.

• Complications:

  • GI upset, ulcers, and GI bleeding.

  • Kidney injury, particularly in clients with dehydration or existing kidney disease.

  • Increased bleeding risk.

  • Fluid retention and increased blood pressure.

• Nursing Interventions:

  • Monitor for black or tarry stools (melena).

  • Monitor renal function tests: Blood Urea Nitrogen (BUN) and creatinine.

  • Assess the client for bruising or active bleeding.

  • Administer medication with food or milk to mitigate GI upset.

• Client Education:

  • Avoid the concurrent use of multiple NSAIDs.

  • Report vomiting blood (hematemesis) or black stools.

  • Avoid alcohol consumption due to increased bleeding risk.

  • Maintain hydration unless medically contraindicated.

• ATI/NCLEX Pearl: Associate NSAIDs with bleeding, kidney function, and stomach irritation. Ketorolac is notably strong and carries a high risk for GI and renal complications.

Celecoxib (Second-Generation NSAID)

• Category/Class: Selective COX-2 inhibitor.

• Purpose of Medication:

  • Treatment of arthritis pain.

  • Reduction of inflammation.

  • Provides less GI irritation than traditional (first-generation) NSAIDs.

  • Used for chronic inflammatory pain management.

• Expected Pharmacological Action:

  • Selectively inhibits the COX-2 enzyme.

  • Decreases inflammation and pain.

  • Exerts less effect on platelet function compared to aspirin.

  • Maintains a serious cardiovascular risk profile.

• Complications:

  • Cardiovascular events (e.g., myocardial infarction, stroke).

  • GI bleeding (still possible, though less likely than non-selective NSAIDs).

  • Kidney injury.

  • Concern regarding sulfonamide (sulfa) allergy.

• Nursing Interventions:

  • Assess the client's history for heart disease.

  • Monitor blood pressure levels.

  • Monitor kidney function.

  • Inquire about sulfa allergies.

• Client Education:

  • Immediately report chest pain or shortness of breath.

  • Do not combine with other NSAIDs.

  • Adhere strictly to the prescribed dosage.

  • Report swelling or sudden weight gain.

• ATI/NCLEX Pearl: Celecoxib is COX-2 selective but can still adversely affect the heart and kidneys.

Acetaminophen

• Prototype: Acetaminophen (APAP).

• Category/Class: Non-opioid analgesic and antipyretic.

• Purpose of Medication:

  • Mild to moderate pain relief.

  • Fever reduction.

  • Treatment of headache and muscle aches.

  • Frequently combined with opioids in various formulations.

• Expected Pharmacological Action:

  • Acts primarily within the Central Nervous System (CNS).

  • Reduces pain and fever.

  • Does not significantly reduce inflammation.

  • Does not increase bleeding risk like NSAIDs.

• Complications:

  • Liver toxicity (hepatotoxicity).

  • High risk of overdose.

  • Increased toxicity risk when used with alcohol.

  • Risk of unintentional overdose due to its presence in many combination medications.

• Nursing Interventions:

  • Verify the total daily dose from all sources.

  • Monitor liver function tests (LFTs) during long-term use.

  • Assess the client's alcohol consumption habits.

  • Monitor for signs of overdose: nausea, vomiting, and Right Upper Quadrant (RUQ) pain.

• Client Education:

  • Do not exceed $4,000\,mg/day$.

  • Avoid alcohol.

  • Check all medication labels for "APAP."

  • Report jaundice (yellowing of skin/eyes) or dark urine.

• ATI/NCLEX Pearl: Acetaminophen affects the liver; NSAIDs affect the kidneys, stomach, and bleeding.

Opioid Agonists and Antagonists

Opioid Agonists

• Prototypes: Morphine, Fentanyl, Oxycodone, Hydromorphone, Codeine, Methadone.

• Category/Class: Opioid analgesics.

• Purpose of Medication:

  • Moderate to severe pain management.

  • Post-operative pain.

  • Cancer-related pain.

  • Chronic severe pain cases.

• Expected Pharmacological Action:

  • Stimulates opioid receptors in the CNS.

  • Decreases pain perception.

  • Induces CNS depression, producing sedation and analgesia.

• Complications:

  • Respiratory depression.

  • Sedation.

  • Constipation.

  • Hypotension.

• Nursing Interventions:

  • Verify respiratory rate (RR) before administration.

  • Assess Level of Consciousness (LOC) and sedation level.

  • Ensure naloxone is available as a reversal agent.

  • Initiate a bowel regimen early to prevent constipation.

• Client Education:

  • Avoid alcohol and other CNS sedatives.

  • Change positions slowly to avoid orthostatic hypotension.

  • Increase fluid and fiber intake if not contraindicated.

  • Avoid driving until the medication's effects on the individual are known.

• ATI/NCLEX Pearl: The priority assessments before giving an opioid are respiratory rate and LOC.

Agonist-Antagonist Opioids

• Prototype: Butorphanol.

• Category/Class: Mixed opioid agonist-antagonist.

• Purpose of Medication:

  • Moderate to severe pain.

  • Migraine pain.

  • Labor pain.

  • Alternative option to pure opioid agonists.

• Expected Pharmacological Action:

  • Activates certain opioid receptors while blocking others.

  • Provides analgesia.

  • Can precipitate immediate withdrawal symptoms in opioid-dependent clients.

• Complications:

  • Sedation and dizziness.

  • Nausea.

  • Respiratory depression is still possible.

• Nursing Interventions:

  • Assess pain levels and sedation scores.

  • Monitor respirations.

  • Inquire about physical dependence on opioids.

  • Implement fall precautions.

• Client Education:

  • Do not mix with alcohol.

  • Sit or lie down if dizziness occurs.

  • Report any difficulty breathing.

  • Avoid driving.

• ATI/NCLEX Pearl: Butorphanol can trigger withdrawal if the client is physically dependent on pure opioid agonists.

Opioid Antagonist

• Prototype: Naloxone.

• Category/Class: Opioid antagonist.

• Purpose of Medication:

  • Reversal of opioid overdose.

  • Reversal of opioid-induced respiratory depression when RR is critically low.

  • Emergency medication.

• Expected Pharmacological Action:

  • Competitive antagonist that blocks opioid receptors.

  • Reverses sedation and improves respiratory drive.

  • Can reverse analgesia, causing the return of pain.

• Complications:

  • Acute withdrawal symptoms.

  • Return of severe pain.

  • Nausea and vomiting.

  • Short duration of action; may require repeated doses compared to the long-acting opioid it is reversing.

• Nursing Interventions:

  • Assess airway first.

  • Monitor RR, oxygen saturation ($SpO_2$), and LOC.

  • Be prepared to administer repeat doses.

  • Continue monitoring even after Initial client improvement.

• Client Education:

  • Naloxone is for emergency use during opioid overdose.

  • Call emergency services immediately after use.

  • The effects can wear off, and withdrawal symptoms are expected.

• ATI/NCLEX Pearl: Naloxone's priority is fixing breathing; the return of pain is an expected outcome.

Adjuvant Medications for Pain

Amitriptyline

• Category/Class: Tricyclic antidepressant (TCA).

• Use in Pain: Neuropathic pain.

• Purpose of Medication:

  • Neuropathic pain management.

  • Depression.

  • Migraine prevention.

  • Support for chronic pain.

• Expected Pharmacological Action:

  • Increases levels of norepinephrine and serotonin.

  • Reduces nerve pain signals.

  • Induces sedation.

  • Possesses anticholinergic effects.

• Complications:

  • Dry mouth, constipation, and urinary retention.

  • Orthostatic hypotension.

• Nursing Interventions:

  • Monitor mood and suicide risk.

  • Assess fall risk.

  • Monitor for urinary retention.

  • Assess cardiovascular history.

• Client Education:

  • Take at bedtime if it causes sleepiness.

  • Change positions slowly.

  • Increase fluid and fiber intake.

  • Do not discontinue the medication suddenly.

• ATI/NCLEX Pearl: TCAs cause anticholinergic effects: "dry mouth, constipation, urinary retention."

Gabapentin

• Category/Class: Anticonvulsant.

• Use in Pain: Neuropathic pain.

• Purpose of Medication:

  • Nerve pain (e.g., diabetic neuropathy, postherpetic neuralgia).

  • Seizures.

• Expected Pharmacological Action:

  • Stabilizes overactive nerve signals.

  • Decreases neuropathic pain signals.

  • Reduces seizure activity.

  • Exerts CNS depressant effects.

• Complications:

  • Dizziness and drowsiness.

  • Ataxia (unsteady gait).

  • Peripheral edema.

• Nursing Interventions:

  • Implement fall precautions.

  • Monitor level of sedation.

  • Assess kidney function.

  • Ensure the medication is not stopped abruptly.

• Client Education:

  • Avoid alcohol.

  • Rise from sitting or lying slowly.

  • Report any changes in mood.

  • Take strictly as prescribed.

• ATI/NCLEX Pearl: Gabapentin is associated with nerve pain management, dizziness, and fall risks.

Migraine Medications

Sumatriptan

• Category/Class: Serotonin receptor agonist; Triptan.

• Purpose of Medication:

  • Acute treatment of migraines.

  • Most effective when taken early in a migraine attack.

  • Not for migraine prevention or regular daily use.

• Expected Pharmacological Action:

  • Stimulates serotonin receptors.

  • Causes cranial blood vessel constriction.

  • Interrupts the migraine pain pathway.

• Complications:

  • Chest tightness and tingling.

  • Dizziness.

  • Serotonin syndrome risk.

• Nursing Interventions:

  • Assess cardiac history (contraindicated in Coronary Artery Disease).

  • Monitor blood pressure.

  • Do not administer with ergot medications.

  • Watch for signs of serotonin syndrome.

• Client Education:

  • Take at the onset of a migraine.

  • Report chest pain immediately.

  • Do not use with ergotamine within a $24\,hour$ window.

  • Avoid overuse (medication-overuse headaches).

• ATI/NCLEX Pearl: Triptans are contraindicated with CAD, history of stroke/TIA, and uncontrolled hypertension.

Ergotamine

• Category/Class: Ergot alkaloid.

• Purpose of Medication:

  • Acute migraine treatment.

  • Used less frequently than triptans.

  • Not for daily use.

  • Induces strong vasoconstriction.

• Expected Pharmacological Action:

  • Constricts cranial blood vessels.

  • Reduces throbbing migraine pain by affecting serotonin receptors.

• Complications:

  • Nausea and vomiting.

  • Numbness and tingling in extremities.

  • Hypertension.

  • Ischemia or ergotism.

• Nursing Interventions:

  • Assess cardiovascular history.

  • Check pregnancy status (contraindicated in pregnancy).

  • Monitor for cold or numb extremities.

  • Avoid use with strong CYP3A4 inhibitors.

• Client Education:

  • Do not take while pregnant.

  • Report chest pain or cold fingers/toes immediately.

  • Do not combine with triptans.

• ATI/NCLEX Pearl: Ergotamine causes vasoconstriction; avoid in pregnancy and vascular disease.

Connective Tissue Disorders

Methotrexate

• Category/Class: Disease-Modifying Antirheumatic Drug (DMARD); Antimetabolite.

• Purpose of Medication: Rheumatoid arthritis (RA), psoriasis, and some cancers.

• Expected Pharmacological Action:

  • Folic acid antagonist.

  • Inhibits rapidly dividing cells.

  • Suppresses the immune response and decreases inflammation in RA.

• Complications:

  • Bone marrow suppression (anemia, leukopenia, thrombocytopenia).

  • Hepatotoxicity and pulmonary toxicity.

  • Teratogenicity (birth defects).

• Nursing Interventions:

  • Monitor Complete Blood Count (CBC).

  • Monitor liver enzymes and renal function.

  • Assess for mouth sores (stomatitis) or signs of infection.

• Client Education:

  • Avoid alcohol and pregnancy.

  • Report fever, sore throat, or mouth ulcers.

  • Take folic acid if prescribed to mitigate side effects.

• ATI/NCLEX Pearl: Methotrexate risks involve the liver, bone marrow, lungs, and pregnancy.

Etanercept

• Category/Class: Biologic DMARD; Tumor Necrosis Factor (TNF) inhibitor.

• Purpose of Medication: RA, psoriatic arthritis, and ankylosing spondylitis.

• Expected Pharmacological Action:

  • Blocks TNF-alpha to decrease inflammation.

  • Slows joint damage and suppresses the immune response.

• Complications:

  • Serious infections and Tuberculosis (TB) reactivation.

  • Injection-site reactions.

  • Possible malignancy risk.

• Nursing Interventions:

  • Screen for TB prior to starting therapy.

  • Monitor for signs of infection.

  • Ensure the client avoids live vaccines.

• Client Education:

  • Report fever or cough immediately.

  • Avoid contact with sick individuals.

  • Rotate injection sites.

• ATI/NCLEX Pearl: Biologic DMARDs increase infection risk; always screen for TB.

Auranofin

• Category/Class: Gold compound DMARD.

• Purpose of Medication: RA (slows disease progression).

• Expected Pharmacological Action: Modifies the immune response to decrease inflammation and joint damage. Takes weeks to months to be effective.

• Complications: Diarrhea, rash, stomatitis, and bone marrow suppression.

• Nursing Interventions: Monitor CBC, kidney function, and skin/mouth condition.

• Client Education: Report mouth ulcers, unusual bleeding, or rash. It takes time to work.

Cyclosporine

• Category/Class: Immunosuppressant; calcineurin inhibitor.

• Purpose of Medication: Prevention of transplant rejection, autoimmune disorders, and severe RA.

• Expected Pharmacological Action: Inhibits T-cell activation to suppress the immune system.

• Complications: Nephrotoxicity, hypertension, infection, and gingival hyperplasia.

• Nursing Interventions: Monitor creatinine, blood pressure, and drug levels.

• Client Education: Avoid grapefruit; report decreased urine output; maintain good oral hygiene.

• ATI/NCLEX Pearl: Cyclosporine affects kidneys, BP, and increases infection risk.

Gout Medications

Colchicine

• Category/Class: Antigout medication for inflammation.

• Purpose: Acute gout flares or prevention of flares. Does NOT lower uric acid levels.

• Action: Inhibits neutrophil activity to reduce inflammation and pain.

• Complications: Diarrhea, nausea, bone marrow suppression, and muscle toxicity.

• ATI/NCLEX Pearl: Toxicity often begins with GI symptoms (severe diarrhea).

Allopurinol

• Category/Class: Xanthine oxidase inhibitor.

• Purpose: Long-term prevention of gout attacks and kidney stones; lowers uric acid levels.

• Action: Inhibits uric acid production.

• Complications: Rash, Stevens-Johnson Syndrome, hepatotoxicity, and kidney injury.

• ATI/NCLEX Pearl: Allopurinol prevents gout; colchicine treats the acute inflammation.

Systemic Lupus Erythematosus (SLE)

Belimumab

• Category/Class: Monoclonal antibody.

• Purpose: Treatment of SLE flares.

• Expected Pharmacological Action: Blocks B-lymphocyte stimulators to reduce autoantibody activity.

• Complications: Infection, infusion reactions, depression/mood changes.

• Client Education: Report mood changes or suicidal thoughts.

Immunizations and Immunoglobulin

• Vaccines (Active Immunity): Prototypes include Tdap, Hepatitis B, Influenza, MMR, Varicella, Pneumococcal, Herpes Zoster. Stimulate antibody production and memory.

  • Live Vaccines: MMR and Varicella (Avoid in pregnancy/immunocompromise).

• Immunoglobulin G (Passive Immunity): Provides immediate, temporary antibodies after exposure or in deficiency. Does not create long-term memory. Risk of infusion reactions and kidney dysfunction.

Chemotherapy and Growth Factors

• Tamoxifen: Estrogen receptor blocker for breast cancer. Increases risk for venous thromboembolism (VTE) and endometrial cancer. Report calf pain or abnormal vaginal bleeding.

• Interferon alfa-2b: Biologic response modifier. Complications include flu-like symptoms and depression.

• Cetuximab: EGFR inhibitor for colorectal/head and neck cancer. Risks: Infusion reaction, acne-like rash, and hypomagnesemia ($Mg^{2+}$).

• Epoetin alfa: Stimulates RBC production for anemia. Risk of hypertension ($BP$) and clots. Monitor hemoglobin ($Hgb$).

• Filgrastim: Stimulates WBC/neutrophil production. Common complication is bone pain. Monitor Absolute Neutrophil Count (ANC).

Practice Questions and Answers

1. NSAID/Ibuprofen: Client reports black tarry stools. Action: B. Hold medication and notify provider.

2. Naproxen Monitoring (SATA): Answers: A (GI Bleeding), B (Kidney injury), C (Bruising), E (Increased BP).

3. Acetaminophen Understanding: Answer: B. "I should avoid alcohol while taking this."

4. Acetaminophen/RUQ Pain/Jaundice: Answer: B. Liver toxicity.

5. Morphine Priority: Answer: B. Respiratory rate.

6. Hydromorphone/RR 8: Answer: B. Naloxone.

7. Naloxone Expectation: Answer: A. Pain may return.

8. Butorphanol/Opioid Dependence: Answer: B. It can precipitate withdrawal.

9. Amitriptyline Side Effect: Answer: A. Dry mouth.

10. Amitriptyline Teaching: Answer: C. "I should stop this medication suddenly…" (Requires more teaching).

11. Gabapentin Safety: Answer: B. Fall precautions.

12. Sumatriptan Contraindication: Answer: B. Coronary artery disease.

13. Sumatriptan Statement: Answer: B. "I should take it at the onset of migraine symptoms."

14. Ergotamine/Cold fingers: Answer: B. Report immediately (Ischemia).

15. Methotrexate/Bone Marrow: Answer: A. CBC.

16. Methotrexate Teaching (SATA): Answers: A (Avoid alcohol), B (Mouth sores), C (Avoid pregnancy), D (Report fever).

17. Etanercept Screening: Answer: B. TB screening.

18. Cyclosporine Monitoring: Answer: A. Nephrotoxicity.

19. Colchicine/Diarrhea: Answer: B. Hold medication and notify provider.

20. Allopurinol Thinking: Answer: B. "This helps prevent future gout attacks."

21. Live Vaccines: Answer: A. MMR and varicella.

22. Vaccine vs Immunoglobulin: Answer: B. Vaccine is active; immunoglobulin is passive.

23. Tamoxifen Reporting: Answer: B. Calf pain and swelling (VTE).

24. Interferon Assessment: Answer: A. Depression.

25. Cetuximab Lab: Answer: A. Low magnesium.

26. Epoetin concern: Answer: A. Blood pressure $180/96\,mmHg$.

27. Filgrastim Effectiveness: Answer: A. Increased neutrophil count.

Dosage Calculations

1. Acetaminophen Daily Max:

   • Order: $650\,mg$ every $6\,hr$.

   • Calculation: $650\,mg \times 4\,\text{doses/day} = 2,600\,mg/day$.

2. Morphine Volume:

   • Order: $2\,mg$; Available: $4\,mg/mL$.

   • Calculation: $2\,mg \div 4\,mg/mL = 0.5\,mL$.

3. Naloxone Volume:

   • Order: $0.4\,mg$; Available: $0.4\,mg/mL$.

   • Calculation: $0.4\,mg \div 0.4\,mg/mL = 1\,mL$.

4. Ketorolac Volume:

   • Order: $15\,mg$; Available: $30\,mg/mL$.

   • Calculation: $15\,mg \div 30\,mg/mL = 0.5\,mL$.

5. Fentanyl Infusion Rate:

   • Order: $1\,mcg/kg/hr$; Weight: $154\,lb$ ($70\,kg$); Available: $500\,mcg$ in $100\,mL$.

   • Calculation: $1\,mcg \times 70\,kg = 70\,mcg/hr$.

   • Concentration: $500\,mcg \div 100\,mL = 5\,mcg/mL$.

   • Rate: $70\,mcg/hr \div 5\,mcg/mL = 14\,mL/hr$.

6. Complex Infusion Pump Rate:

   • Order: $10\,mcg/kg/min$; Weight: $120\,lb$ ($54.5\,kg$); Available: $800\,mg$ in $500\,mL$.

   • Calculation: $10\,mcg \times 54.5\,kg = 545\,mcg/min$.

   • Hourly Rate (mcg): $545\,mcg/min \times 60\,min/hr = 32,700\,mcg/hr$.

   • Hourly Rate (mg): $32,700\,mcg \div 1,000 = 32.7\,mg/hr$.

   • Concentration: $800\,mg \div 500\,mL = 1.6\,mg/mL$.

   • Pump Setting: $32.7\,mg/hr \div 1.6\,mg/mL = 20.4\,mL/hr$ (Rounded: $20\,mL/hr$).