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COX Inhibitors
Pharmacology
Question | Answer |
---|---|
What is COX? | Cyclooxygenase, the enzyme that converts arachidonic acid into prostanoids: prostaglandins and related compounds |
What are the useful effects of COX inhibitors? | Suppress inflammation, relieve pain, and reduce fever |
What is the only COX inhibitor that can protect against MI and stroke? | Aspirin |
What are the principal adverse effects of COX inhibitors? | Gastric ulceration, bleeding, and renal impairment |
What are the two forms of cyclooxygenase? | COX-1 and COX-2 |
Where is COX-1 found? | In all tissues |
Where is COX-2 found? | At sites of tissue injury |
What are the actions of COX-2? | It mediates inflammation and sensitizes receptors to painful stimuli |
What are the actions of COX-1? | Supports renal function, protects gastric mucosa, and promotes platelet aggregation |
Which is the "bad" COX? | COX-2 |
Which the "good" COX? | COX-1 |
What are the 2 major groups of COX inhibitors? | Drugs with antiinflammatory processes (NSAIDs) and drugs without antiinflammatory properties |
What is the only COX inhibitor that lacks antiinflammatory processes? | Acetaminophen |
What are the 2 groups of NSAIDs? | First generation and second generation |
How do first generation NSAIDs act? | By inhibiting COX-1 AND COX-2 |
What is the indication for use of first generation NSAIDs? | To treat inflammatory disorders (e.g., RA), alleviate mild to moderate pain, and to suppress fever |
What is the prototype first generation NSAID? | Aspirin |
What are salicylates associated with? | Aspirin |
Which NSAID is a nonreversible inhibitor of COX? | Aspirin |
How is aspirin absorbed after PO dosing? | Rapidly and completely from the small intestine |
How is aspirin excreted? | By the kidneys |
What is salicylism? | Aspirin toxicity |
When does severe salicylism occur? | When plasma drug levels of aspirin exceed 400 mcg/mL |
How long before surgery should aspirin use be discontinued? | At least 1 week |
True of False; The renal impairment caused by aspirin is reversible. | True |
What are signs and symptoms of salicylism? | Tinnitus, sweating, headache, and dizziness |
Why is aspirin use in children with chicken pox or the flu life threatening? | Because it can cause Reye's syndrome |
What are the signs and symptoms of Reye's syndrome? | Encephalopathy and fatty liver degeneration |
What effect can aspirin have on labor? | It can prolong it |
Does aspirin increase the risk of thrombotic events? | No |
True of False: Daily use of aspirin is not associated with erectile dysfunction. | False |
Can the use of COX inhibitors blunt the immune response to vaccines? | Yes |
What is the lethal dose of aspirin in an adult? | 20-25 gm |
What is the lethal dose of aspirin in a child? | 4 gm |
Describe treatment for acute salicysim. | Largely supportive |
What is the principal use for nonaspirin first generation NSAIDs? | RA and osteoarthritis |
True or False: The use of nonaspirin first generation NSAIDs increase the risk of thrombotic events? | True |
What is an example of a nonaspirin first generation NSAID? | Ibuprofen |
What are coxibs? | Second generation NSAIDs |
How do second generation NSAIDs act? | By inhibiting COX-2 |
Which NSAID is considered a last-choice drug for treatment of long-term pain? | Celebrex |
What are the most common adverse effects of Celebrex? | Dysepsia and abdominal pain |
Which NSAID is contraindicated in patients with a sulfa allergy? | Celebrex |
How does acetaminophen act? | By inhibiting COX only in the CNS; it's inhibition is minimal at peripheral sites |
What can acetaminophen overdose cause? | Serious liver damage |
What 3 medical emergencies are associated with acetaminophen? | Stevens-Johnson Syndrome, acute generalized exanthematous pustulosis, and toxic epidermal necrolysis |
What are signs and symptoms of acute poisoning from acetaminophen? | N/V, diarrhea, sweating, and abdominal discomfort which progress to hepatic necrosis, coma, and death |
How can acute acetaminophen poisoning be treated? | With Mucomyst |