What does the lipoxygenase pathway of the arachidonic acid pathway yield?
Leukotrienes (remember: L for Lipoxygenase and Leukotrienes)
Which arachidonic acid product is a neutrophil chemotactic agent?
Leukotriene B4 (remember: Neutrophils arrive B4 others)
What effect do leukotrienes C4, D4, and E4 have on the bronchi and the bronchioles?
What effect do leukotrienes C4, D4, and E4 have on the vasculature?
Vasoconstriction and increase vascular permeability
What effect does prostacyclin (PGI2) have on platelets?
Inhibits platelet aggregation (remember Platelet-Gathering Inhibitor)
What effect does prostacyclin (PGI2) have on the vasculature?
What is the first step of the arachidonic acid pathway?
Membrane lipids are converted to arachidonic acid by phospholipase A2
Within the arachidonic acid cascade, what two enzymes use arachidonic acid as their substrate?
Lipoxygenase and cyclooxygenase
What drug inhibits the enzyme lipoxygenase?
What are the two mechanisms of action of steroids on the arachidonic acid pathway?
Steroids inhibit the action of phospholipase and inhibit the synthesis of cyclooxygenases
Cyclooxygenase directly converts arachidonic acid into what category of compounds resulting in what two products?
Endoperoxides; prostaglandins G and H
Hydroperoxides are the precursors of what class of arachidonic acid products?
Endoperoxides are the precursors of what three arachidonic acid products?
Prostacyclin, prostaglandins, and thromboxane
List two drugs that inhibit leukotrienes from producing an increase in bronchial tone.
Zafirlukast and montelukast
Name three effects of prostacyclin.
Prostacyclin decreases platelet aggregation, causes vasodilation and decreases uterine tone
Name four effects of prostaglandins on the body.
Prostaglandins cause a decrease in vascular tone, increase in pain, increase in uterine tone, increase in temperature
Zileuton inhibits the conversion of _____ to _____.
arachidonic acid to hydroperoxides
Aspirin _____ (reversibly/irreversibly) inhibits cyclooxygenase.
Aspirin causes a decrease in synthesis of what two products?
Thromboxane and prostaglandins
At what dose does aspirin cause decreased platelet aggregation?
Low-dose; < 300 mg/day
At what dose does aspirin have antipyretic and analgesic properties?
Intermediate dose; 300-2400 mg/day
At what dose does aspirin have antiinflammatory properties?
High dose; 2400-4000 mg/day
What is a common toxicity of aspirin use?
Chronic use of aspirin can cause what three problems?
Acute renal failure, interstitial nephritis, and upper gastrointestinal bleeding
What syndrome can develop in children with viral illnesses who are given aspirin?
Name four examples of nonsteroidal antiinflammatory drugs.
Ibuprofen, naproxen, indomethacin, and ketorolac
Nonsteroidal antiinflammatory drugs work by reversibly inhibiting what substance?
Do ibuprofen, naproxen, indomethacin, and ketorolac inhibit cyclooxygenase-1, cyclooxygenase-2, or both?
Nonsteroidal antiinflammatory drugs block the synthesis of what substance?
What are the three effects of administration of nonsteroidal antiinflammatory drugs?
They are antipyretics, analgesics, and antiinflammatory agents