Anti-Inflammatory, Anti-Arthritis, and Related Agents

Explaining Anti-Inflammatory, Anti-Arthritis, and Related Agents

This lecture covers the therapeutic actions, uses, and nursing implications of various pharmaceutical agents used to manage inflammation and arthritis.

Key Terms

  • Analgesic: A pain reliever.

  • Anti-inflammatory agents: Drugs that block or alter the chemical reactions involved in inflammation.

  • Crystal therapy: Inflammation treatment using gold salts.

  • Disease-Modifying Antirheumatic Drugs (DMARDs): Drugs used in arthritis treatment; include tumor necrosis factor (TNF) blockers.

  • Gout: A condition characterized by high uric acid in the body, leading to deposits of uric crystals in kidneys or joints.

  • Inflammatory Bowel Disease (IBD): Chronic inflammation of the gastrointestinal (GI) tract.

  • Inflammatory response: The body's reaction to perceived harmful stimuli (e.g., bacteria, trauma, toxins).

  • Nonsteroidal Anti-inflammatory Drugs (NSAIDs): Drugs with anti-inflammatory, analgesic, and antipyretic (fever-reducing) effects.

  • Salicylates: Agents primarily possessing antipyretic and analgesic properties.

  • Salicylism: A condition resulting from too much aspirin or salicylates, manifesting as dizziness, nausea, vomiting, tinnitus (ear ringing), difficulty hearing, mental confusion, and possibly diarrhea.

The Inflammatory Response

  • Body's Protective Mechanism: The inflammatory response is a crucial way the body protects itself from various threats such as bacteria, trauma, or toxins.

  • Cardinal Signs of Inflammation:

    • Pain: Acts as an alert that something is wrong.

    • Heat: Aims to destroy pathogens.

    • Redness: Caused by enlarged blood vessels increasing blood flow to the area.

    • Swelling: Results from chemical reactions of the immune system activating.

    • Loss of Function: Prevents further injury to the affected area.

  • Moderation is Key: While beneficial, excessive or inappropriate inflammatory responses can worsen a patient's condition.

General Considerations for Anti-inflammatory Agents

  • Adverse Effects: All anti-inflammatory agents, including over-the-counter (OTC) options, carry risks of adverse effects.

  • Masking Symptoms: OTC anti-inflammatory drugs can mask signs and symptoms, potentially leading to misdiagnosis when a patient eventually seeks professional care.

  • Patient Assessment: Always inquire about any home remedies or OTC medications a patient has used to manage their ailment.

  • Professional Consultation: Patients on prescribed anti-inflammatory drugs should always check active ingredients and consult their provider before taking any additional OTC medications.

  • Reye's Syndrome: Children taking salicylate-containing medications during fever or viral infections are at risk for Reye's syndrome, which can cause liver failure and encephalopathy.

  • Gold Salts (Crystal Therapy): Generally used as a last resort due to significant risks often outweighing benefits in many patients.

  • Pregnancy and Lactation: Anti-inflammatory use is generally not advised unless the benefits unequivocally outweigh the risks.

  • Older Adults: Increased toxicity risk for both gold salts and regular anti-inflammatory agents, meaning they should be avoided if possible in this population.

Salicylates

  • Therapeutic Actions: Primarily affect fever and pain, derived from willow bark.

  • Safety Profile: Generally safe without a prescription if dosing directions are followed.

  • Types of Salicylates:

    • Aspirin: Used to treat various inflammatory conditions.

    • Mesalamine: Specifically used to treat inflammation of the large intestine.

  • Mechanism of Action: These drugs reduce pain and fever by interrupting prostaglandin production.

  • Significant Effects & Contraindications:

    • Blood Thinning Effect: Contraindicated in patients with clotting problems or impending surgery.

    • Reye's Syndrome: Avoid in children with viral infections due to this risk.

    • Drug Interactions: Can interfere with many drugs, causing malabsorption. Always consult a reliable resource before adjusting a salicylate in a patient's regimen.

  • Salicylism (Mild Overdose): Presents with lack of energy, nausea, vomiting, diarrhea, confusion, fever, and ringing ears (tinnitus).

  • Salicylate Toxicity (Severe Overdose): Indicated by pulmonary edema, convulsions, tetany, severe fever, coma, dehydration, tachycardia, and potentially cardiovascular, renal, and respiratory failure.

  • Nursing Implications:

    • Assessment:

      • Assess for contraindications.

      • Monitor skin for increased risk of reactions and rashes.

      • Assess central nervous system (CNS) status for signs of toxic levels.

      • Monitor for persistent fever, heart rate changes, and respiratory status.

      • Laboratory Tests: Complete Blood Count (CBC), Blood Urea Nitrogen (BUN), creatinine, Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Urinalysis (UA), Prothrombin Time (PT), Partial Thromboplastin Time (PTT). A stool guaiac test is used to check for GI bleeding.

    • Administration: Best taken with food to reduce GI upset and potential stomach lining damage. Verify the patient is not taking other salicylate-containing medications.

    • Monitoring: Vigilantly observe for signs of salicylism or salicylate toxicity, and monitor for excessive bleeding.

    • Evaluation: Ensure patient understands their medication comprehensively.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

  • Therapeutic Actions: Possess potent anti-inflammatory, analgesic, and antipyretic effects with fewer complications compared to corticosteroids.

  • Misuse Risks: Common misuse can lead to severe GI bleeds, liver damage, or kidney damage, often requiring hospitalization.

  • Classification and Examples:

    • Propionic Acids: Ibuprofen, Naproxen

    • Oxycam Derivatives: Meloxicam

    • Acetic Acids: Indomethacin, Ketorolac

    • Cyclooxygenase-2 (COX-2) Inhibitors: Celecoxib

  • Mechanism of Action (COX-1 vs. COX-2):

    • COX-1: Found in tissues throughout the body, involved in clotting, renal sodium and water balance, and stomach protection. Blocking COX-1 can lead to GI upset, kidney issues, and increased bleeding.

    • COX-2: Primarily involved in the inflammatory reaction.

    • Differential Effects: NSAIDs with higher COX-1 blocking power are more likely to cause GI effects, bleeding, and kidney problems. NSAIDs with higher COX-2 blocking power are more likely to cause cardiovascular issues.

  • Contraindications and Adverse Effects:

    • Cardiovascular Risks: Can increase the risk of heart attack and stroke, especially in patients with pre-existing cardiovascular problems.

    • Gastrointestinal: Peptic ulcers can worsen with NSAID use; GI effects are very common.

    • Celecoxib: Contraindicated in patients with a sulfonamide allergy because it contains a sulfonamide group.

    • Chronic Use ($$>$3$ months daily): May lead to cardiovascular and CNS effects, and decreased bone marrow production.

    • Prostaglandins' Broad Role: Prostaglandins are involved in inflammation, pain regulation, cardiovascular function, GI protection, and immune response. Their inhibition can lead to diverse and seemingly unrelated adverse effects across multiple body systems.

  • Drug-Drug Interactions:

    • Loop Diuretics: NSAIDs can reduce their effectiveness due to prostaglandin involvement in fluid and electrolyte balance.

    • Beta Blockers: Effectiveness can be reduced or negated due to NSAID-induced hypertension.

    • Lithium: Increased risk of lithium toxicity when combined with NSAIDs.

    • Anticoagulants: NSAIDs can significantly increase the blood-thinning effects of anticoagulants, raising bleeding risk.

    • Hepatotoxic Medications: Not recommended for patients taking other potentially hepatotoxic drugs due to increased risk of liver damage.

  • Nursing Implications: Nursing diagnoses for NSAIDs are similar to those for salicylates.

Acetaminophen

  • Therapeutic Actions: Drug of choice for managing pain and fever in children, as it does not carry the risk of masking Reye's syndrome.

  • Mechanism of Action: Acts on thermoregulatory cells, causing vasodilation and sweating, which helps the body cool down.

  • Contraindications:

    • Known allergy.

    • Pregnancy/Lactation (assess benefits vs. risks).

    • Any form of liver problems due to the potential for serious liver damage.

    • Alcoholism, as it predisposes to liver problems.

  • Adverse Effects:

    • Rebound headaches (with chronic use).

    • Hemolytic anemia (rare).

    • Skin rash and fever (sensitivity reactions).

  • Overdose: Can cause severe liver damage leading to death.

  • Antidote: Acetylcysteine replenishes liver glutathione levels, which neutralizes toxic metabolites, and directly binds to these metabolites to reduce their effect.

  • Nursing Implications:

    • Patient Education: Crucially educate parents/guardians about acetaminophen content in other products to prevent accidental overdose in children.

    • Assessment: Monitor liver and kidney function, assess for GI bleeds, and observe for changes in mental status, which could indicate an overdose.

Anti-Arthritis Agents: Gold Salts (Auranofin)

  • Therapeutic Actions: A type of crystal therapy used to minimize tissue damage and inflammation in arthritis. It prevents further damage but cannot repair existing tissue damage; most effective when given early.

  • Toxicity: Highly toxic, reserved only for cases where traditional treatments have failed.

  • Contraindications:

    • Patients with impaired organs (heart, liver, or kidney problems).

    • Blood dyscrasias (can be exacerbated).

  • Adverse Effects:

    • Can provoke an inappropriate immune response, leading to inflammation in other tissues, potentially severe enough to cause anaphylactic shock.

    • Bone marrow suppression results from the drug's toxicity.

  • Drug Interactions: Combining auranofin with other specific drugs significantly increases the likelihood of severe toxicity.

Anti-Arthritis Agents: Disease-Modifying Antirheumatic Drugs (DMARDs)

  • Type: Biologic or non-biologic. The focus here is on Tumor Necrosis Factor (TNF) blockers, which are biologic DMARDs.

  • Examples of TNF Blockers (Monoclonal Antibodies): Etanercept (a receptor fusion protein), Adalimumab, Infliximab. The