Chapter 44 Antiinflammatory and Antigout Drugs 1 Fall 2012

NSAIDs non-steroidal anti-inflammatory drugs Large and chemically diverse group of drugs with the following properties:  Analgesic  Antiinflammatory  Antipyretic  Antirheumatic 2 Fall 2012

NSAIDs: Mechanism of Action Activation of the arachidonic acid pathway causes:  Pain  Headache  Fever  Inflammation 3 Fall 2012

NSAIDs: Mechanism of Action (cont’d) Analgesia—treatment of headaches, mild to moderate pain, and inflammation  Block the chemical activity of either or both COX enzymes (prostaglandin [PG] pathway) and lipoxygenase (LT pathway)  Result in limiting the undesirable inflammatory effect of PGs 4 Fall 2012

NSAIDs: Mechanism of Action (cont’d) Antipyretic—reduces fever  Inhibits prostaglandin within the area of the brain that controls temperature 5 Fall 2012

Chemical Categories of NSAIDs Salicylates Acetic acid derivatives Cyclooxygenase-2 (COX-2) inhibitors Enolic acid derivatives Propionic acid derivatives 6 Fall 2012

NSAIDs: Salicylates Salicylates also have antiplatelet activity  Inhibit platelet aggregation  Examples: aspirin, diflunisal (Dolobid), others 7 Fall 2012

NSAIDs: Acetic Acids indomethacin (Indocin) ketorolac (Toradol) diclofenac sodium (Voltaren) sulindac (Clinoril) tolmetin (Tolectin) etodolac (Lodine) 8 Fall 2012

NSAIDs: COX-2 Inhibitor celecoxib (Celebrex)  First and only remaining COX-2 inhibitor  Indicated for osteoarthritis, rheumatoid arthritis, acute pain symptoms, ankylosing spondylitis, and primary dysmenorrhea 9 Fall 2012

NSAIDs: Enolic Acid Derivatives piroxicam (Feldene) meloxicam (Mobic) namumetone (Relafen) 10 Fall 2012

NSAIDs: Propionic Acids fenoprofen (Nalfon) flurbiprofen (Ansaid) ibuprofen (Motrin, Advil, others) ketoprofen (Orudis KT) naproxen (Naprosyn, Aleve) oxaprozin (Daypro) 11 Fall 2012

NSAIDs: Indications Analgesia (mild to moderate) Antigout effects Antiinflammatory effects Antipyretic effects Relief of vascular headache Platelet inhibition (aspirin) 12 Fall 2012

NSAIDs: Indications (cont’d) Relief of mild to moderate pain Acute gout Various bone, joint, and muscle pain Osteoarthritis Rheumatoid arthritis 13 Fall 2012

NSAIDs: Indications (cont’d) Rheumatoid arthritis Dysmenorrhea Fever Many other conditions 14 Fall 2012

Salicylates: Indications Salicylic acid (aspirin) More potent effect on platelet aggregation and thermal regulatory center in the brain  Analgesic  Antipyretic  Antiinflammatory Antithrombotic effect: used in the treatment of MI and other thromboembolic disorders 15 Fall 2012

Antigout Drugs: Indications Gout: condition that results from inappropriate uric acid metabolism  Underexcretion of uric acid  Overproduction of uric acid Uric acid crystals are deposited in tissues and joints, resulting in pain 16 Fall 2012

Antigout Drugs: Indications (cont’d) allopurinol (Zyloprim)  Used to reduce production of uric acid colchicine  Reduces inflammatory response to the deposits of urate crystals in joint tissue probenecid (Benemid), sulfinpyrazone (Anturane)  Increase excretion of uric acid in the urine 17 Fall 2012

NSAIDs: Adverse Effects Gastrointestinal Dyspepsia, heartburn, epigastric distress, nausea  GI bleeding*  Mucosal lesions* (erosions or ulcerations) * Misoprostol (Cytotec) can be used to reduce these dangerous effects. 18 Fall 2012

NSAIDs: Adverse Effects (cont’d) Renal Reductions in creatinine clearance Acute tubular necrosis with renal failure Cardiovascular Noncardiogenic pulmonary edema 19 Fall 2012

NSAIDs: Salicylate Toxicity Adults: tinnitus and hearing loss Children: hyperventilation and CNS effects Metabolic acidosis and respiratory alkalosis may be present 20 Fall 2012

NSAIDs: Interactions Serious interactions can occur when given with: Anticoagulants Aspirin Corticosteroids and other ulcerogenic drugs Protein bound drugs Diuretics and ACE Inhibitors Others 21 Fall 2012

Herbal Products: Glucosamine and Chondroitin Used to treat the pain of osteoarthritis Adverse effects  GI discomfort  Drowsiness, headache, skin reactions (glucosamine) Drug interactions  Enhance effects of warfarin  May increase insulin resistance (glucosamine) 22 Fall 2012

NSAIDs: Nursing Implications Before beginning therapy, assess for conditions that may be contraindications to therapy, especially:  GI lesions or peptic ulcer disease  Bleeding disorders Assess for conditions that require cautious use Perform lab studies as indicated (cardiac, renal, and liver function studies, CBC, platelet count) 23 Fall 2012

Nursing Implications Do NOT give salicylates to children and teenagers because of the risk of Reye’s syndrome Because these drugs generally cause GI distress, they are often better tolerated if taken with food, milk, or an antacid to avoid irritation Explain to patients that therapeutic effects may not be seen for 3 to 4 weeks 24 Fall 2012

Nursing Implications (cont’d) Educate patients about the various adverse effects of NSAIDs, and inform them to notify their physician if these effects become severe or if bleeding or GI pain occurs Inform patients to watch closely for the occurrence of any unusual bleeding, such as in the stool Advise patients that enteric-coated tablets should not be crushed or chewed 25 Fall 2012

Nursing Implications (cont’d) Monitor for therapeutic effects, which vary according to the condition being treated  Decrease in swelling, pain, stiffness, and tenderness of a joint or muscle area 26 Fall 2012