Chapter 45 Anti-inflammatory, antiarthritic Drugs

Question 1

NSAIDs mechanism of action and indications

Answer 1

• Has the following properties: analgesic, anti-inflammatory, antipyretic, and antiarthritic
• Analgesic: Blocks the chemical activity of either or both COX enzymes (PG/prostaglandin and LT/leukotriene). This limits the inflammatory effect of PGS
• In comparision, opioids work directly in the brain
• Antipyretic: inhibits prostaglandin E2 within the area of the brain that controls temperature
• Used for acute gout, acute gouty arthritis, acute painful shoulder, fever, mild to moderate pain, juvenile RA, OA, RA, tendonitis
• Effectiveness is limited by a ceiling effect in that a further increase in a dose beyond a certain level increases the risk for adverse effects without an increase in therapeutic effects (unlike opioids)

Question 2

Salicylates

Answer 2

• Have antiplatlet activity by inhibiting platelet aggregation (reduces TXA2 formation within platelets).
• Used prophylactically for cardiac patients (81 or 325 mg
• Contraindicated in children (up to 18) with flulike symptoms because associated with Reye’s syndrome, which is an acute and potentially life threatening neurological condition that can lead to coma and liver damage. Used acetaminophen or ibuprofen instead.

Question 3

COX 1 and 2 enzymes

Answer 3

• COX 1 enzyme has a role in maintaining intact gastric mucosa. This is the reason that NSAIDs that inhibit COX1 have ulcergenic properties and create GI disturbances
• COX 2 allows for beneficial anti-inflammatory effects without GI issues of the nonspecific NSAIDS

Question 4

Classes and drug names

Answer 4

• Acetic Acids: sodium indomethacin and diclofenac
• Carboxylic Acids: acetylsalicylic acid and ketorolac (Toradol)
• Propionic Acids: Ibuprofen
• COX2: celecoxib (Celebrex)

Question 5

NSAIDS contraindications

Answer 5

• Contraindications include vitamin k deficiency, PUD, severe kidney or liver disease, lactation (may inhibit natural PG synthesis and is excreted in the breast milk)
• Patients who have been diagnosed with “Aspirin Triad”: asthma, nasal polyps, and rhinitis should not be given aspirin because of the increased risk of allergic reaction to aspirin. Causes respiratory effect leading to anaphylaxis.

Question 6

Adverse effects

Answer 6

• Adverse effects include heartburn, epigastric distress, nausea, GI bleeding, mucosal lesions, reductions in creatinine clearance, acute tubular necrosis with renal failure, and pulmonary edema
• misoprostol can be used to reduce these dangerous GI effects because it is an Synthetic PGE1 analogue that inhibits gastric acid secretion of parietal cells and also cytoprotective
• kidney function depends on PGs which stimulate vasodilation and increase kidney blood flow

Question 7

Interactions

Answer 7

• Anticoagulants, aspirin, corticosteroids (increase risk for ulcer), and other protein bound drugs
• Activated charcoal is used for NSAID overdose

Question 8

Antigout drugs

Answer 8

• probenecid (Benuryl) and sulfinpyrazone increases the excretion of uric acid in the urine
• Allopurinol reduces the production of uric acid and is used for maintenance therapy
• colchicine reduces inflammatory response to the deposits of urate crystals in joint tissues and is used for acute therapy

Question 9

Antirheumatoid drugs

Answer 9

• Also known as disease modifying antirheumatic drugs (DMARDs)
• Has slow onset of action (several weeks) and may take 3-6 months to see full effects
• Can have much more toxic adverse effects than NSAIDs
• Gold therapy includes: auranofin (Ridaura), gold sodium thiomalate (Myochrysine), and leflunomide (Arava)
• Cheaper drugs include:
  Methotrextate which is commonly used for the treatment of RA even though it is an antineoplastic
  Hydroxychloroquine is also used for RA but is originally used for malaria treatment and prevention

Question 10

Nursing Implications

Answer 10

• Check uric acids levels for gout
• Gold therapy should never be given IV (only IM) and they should be laying down
• Explain to patients that therapeutic effects may not be seen for 3-4 weeks
• Ketorolac is for short term use only (no more then 5 days) and may be take with food to reduce GI upset
• Avoid other ulcerogenic substances in general (alcohol, prednisone, aspirin-containing products, other NSAIDs
• Avoid alcohol