Ch. 71: Cyclooxygen Inhibitors Flashcards Preview

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Flashcards in Ch. 71: Cyclooxygen Inhibitors Deck (17):
1

Cyclooxygenase Inhibitors

Indications:
- suppress inflammation
- relieve pain
- reduce fever
Adverse Effects:
- Gastric Ulceration
- Bleeding
- Renal Impairment
Mechanism of Action
- inhibit COX, enzyme that converts arachidonic acid into prostanoids
Inhibition of COX-1 ("good COX")

2

Inhibition of COX-1: Beneficial Effects

- protection against myocardial infarction (MI)
and stroke
- (bad Effects are gastric ulceration, bleeding and renal impairment)

3

Inhibition of COX-2 ("bad COX): benefical effects

- suppression of inflammation
- alleviation of pain and reduction of fever
- protection against colorectal cancer

4

Classification of Cyclooxygenase Inhibitors

with antiinflammatory properities (nonsteroidal antiinflammatory drugs) NSAIDs
- aspirin, celecoxib, ibuprofen, and naproxen

without antiinflammatory properities (Acetaminophen)

5

First-Generation NSAIDs

- inhibit COX-a and COX-2
- used to treat inflammatory disorders (rheumatoid arthritis): alleviate mild to moderate pain, suppres fever, relieve dysmenorrhea
- suppress inflammation but pose risk of serious harm

6

Aspirin

- nonselective inhibitor of cyclooxygenase
- therapeutic uses: analgesic, antipyretic, antiinflammatory; suppression of platelet aggregation (thrombotic disorder); dysmenorrhea; cancer prevention and prevent Alzheimer's disease

7

Aspirin: Adverse Effects

- GI effects
- bleeding
- renal impairment
- salicyclism: tinnitus, sweating, headache, and dizziness
- Reye's syndrome
- pregnancy: anemia, postpartum hemorrhage, prolong labor
- hypersensitivity reaction

8

Aspirin: Drug Interactions

- Anticoagulants: Warfarin and heparin, glucocorticoids, alcohol, ibuprofen, ACE inhibitors and ARBs
- acute poisoning
- immediate threats to life: resp. depression, hyperthermia, dehydration, and acidosis
- treatment is largely supportive

9

Nonaspirin First-Generation NSAIDs

- aspirin-like drugs with fewer GI, renal, and hemorrhagic effects
- 20+ nonaspirin NSAIDs available (all similar but for unknown reasons some do better on one than another)
- inhibit COX_1 and COX-2: inhibition is reversible (unlike aspirin)
- principle indications: Rheumatoid arthritis and osteoarthritis
- do not protect against MI and stroke

10

First-Generation NSAIDs: Ibuprofen

- inhibit cyclooxyengase and has antiinflammatory, analgesic, and antipyretic actions
- indications: fever, mild to moderate pain, arthritis
- generally well tolerated
- low incidence of adverse effects
- SAFETY ALERT: all first-generation NSAIDs are associated with an increased risk of GI bleeding that can lead to hosp or death

11

Second-Generation NSAIDs

- just as effective as traditional NSAIDs in suppressing inflammation and pain
- somewhat lower risk for GI side effects
- can impair renal function and cause hypertension and edema
- increased risk of MI and stroke

12

Celecoxib

- 2-gen COX-2 inhibitor: fewer adverse effects than 1-gen drugs
- cardiovascular risks, last-choice drug for long-term management of pain
- uses: osteoarthritis, rheumatoid arthritis, acute pain, dysmenorrhea, familial adenomatous polyposis

13

Celecoxib: Adverse Effects

- Dyspepsia
- abdominal pain
- renal impairment
- sulfonamide allergy
- CV impact (stroke, MI)
- use in pregnancy

14

Celecoxib: Drug Interactions

- Warfarin (may decrease diuretic effect of furosemide
- may decrease antihypertensive effect of ACE inhibitors
- may increase levels of lithium
- celecoxib levels may be increased by fluconazole

15

Acetaminophen

therapeutic uses:
- analgesic, antipyretic
- does not have any antiinflammatory or antiheumatic actions
- not associated with Reye's Syndrome
Action:
- inhibits prostaglandin synthesis in CNS

16

Acetaminophen: Adverse Effects

- very few at normal doses
- Stevens-Johnson Syndrome (SJS) , acute generalized exanthematous pustulosis (AGEP), and toxic epidermal necrolysis (TEN)
- Hepatotoxicity: with an overdose or in patients with liver failure
- Overdose: Hepatic necrosis: signs and symptoms of hepatic failure, coma, death
early symptoms: nausea and vomiting, diarrhea, sweating, ab pain
treatment: Acetylcysteine

17

Acetaminophen: Interactions

- alcohol, Warfarin, and vaccines
- AHA Statement: most COX inhibitors, especially COX-2, increase risk for MI and stroke (AHA recommends a stepped-care approach)