Salicylic acid

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Transcript Salicylic acid

Chapter 44
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Antiinflammatory and Antigout Drugs
Fall 2012
NSAIDs
non-steroidal anti-inflammatory drugs
 Large and chemically diverse group of
drugs with the following properties:
Analgesic
 Antiinflammatory
 Antipyretic
 Antirheumatic

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NSAIDs: Mechanism of Action
 Activation of the arachidonic acid
pathway causes:
Pain
 Headache
 Fever
 Inflammation
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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

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NSAIDs: Mechanism of Action (cont’d)
 Antipyretic—reduces fever
 Inhibits prostaglandin within the area of the
brain that controls temperature
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Chemical Categories of NSAIDs
 Salicylates
 Acetic acid derivatives
 Cyclooxygenase-2 (COX-2)
inhibitors
 Enolic acid derivatives
 Propionic acid derivatives
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NSAIDs: Salicylates
 Salicylates also have antiplatelet
activity
Inhibit platelet aggregation
 Examples: aspirin, diflunisal (Dolobid),
others
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NSAIDs: Acetic Acids
 indomethacin (Indocin)
 ketorolac (Toradol)
 diclofenac sodium (Voltaren)
 sulindac (Clinoril)
 tolmetin (Tolectin)
 etodolac (Lodine)
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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
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NSAIDs: Enolic Acid Derivatives
 piroxicam (Feldene)
 meloxicam (Mobic)
 namumetone (Relafen)
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NSAIDs: Propionic Acids
 fenoprofen (Nalfon)
 flurbiprofen (Ansaid)
 ibuprofen (Motrin, Advil, others)
 ketoprofen (Orudis KT)
 naproxen (Naprosyn, Aleve)
 oxaprozin (Daypro)
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NSAIDs: Indications
 Analgesia (mild to moderate)
 Antigout effects
 Antiinflammatory effects
 Antipyretic effects
 Relief of vascular headache
 Platelet inhibition (aspirin)
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NSAIDs: Indications (cont’d)
 Relief of mild to moderate pain
 Acute gout
 Various bone, joint, and muscle
pain
 Osteoarthritis
 Rheumatoid arthritis
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NSAIDs: Indications (cont’d)
 Rheumatoid arthritis
 Dysmenorrhea
 Fever
 Many other conditions
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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
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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
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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)

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Increase excretion of uric acid in the urine
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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.
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NSAIDs: Adverse Effects (cont’d)
Renal
 Reductions in creatinine clearance
 Acute tubular necrosis with renal
failure
Cardiovascular
 Noncardiogenic pulmonary edema
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NSAIDs: Salicylate Toxicity
 Adults: tinnitus and hearing loss
 Children: hyperventilation and CNS
effects
 Metabolic acidosis and respiratory
alkalosis may be present
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NSAIDs: Interactions
Serious interactions can occur when given with:
 Anticoagulants
 Aspirin
 Corticosteroids and other ulcerogenic drugs
 Protein bound drugs
 Diuretics and ACE Inhibitors
 Others
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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)
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NSAIDs: Nursing Implications
 Before beginning therapy, assess for
conditions that may be contraindications to
therapy, especially:

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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)
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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
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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
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Nursing Implications (cont’d)
 Monitor for therapeutic effects, which vary
according to the condition being treated

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Decrease in swelling, pain, stiffness,
and tenderness of a joint or muscle area
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