Musculoskeletal/Skin/CT- Pharmacology

Question 1

What breaks down membrane phospholipids to arachidonic acid?

Answer 1

phospholipase A2

Question 2

What drugs prevent the action of phospholipase A2?

Answer 2

corticosteroids (e.g. cortisone, hydrocortisone, prednisone,, dexamethasone)

Question 3

What two things can happen to arachidonic acid?

Answer 3

1) lipoxygenase can convert it to 5-HPETE
2) COX1/2 can convert it to the cyclic endoperoxides (prostacyclin (PGI2), prostaglandins, and thromboxane (TXA2))

Question 4

What drug can inhibit the action of lipoxygenase?

Answer 4

Zileuton (used in tx of asthma)

Question 5

5-HPETE is converted to leuktrienes such as LTC4, LTD4, LTE4, and LTB4. What does LTB4 do?

Answer 5

neutrophil chemotaxis

Question 6

5-HPETE is converted to leuktrienes such as LTC4, LTD4, LTE4, and LTB4. What do LTC4, LTD4, and LTE4 do?

Answer 6

increase bronchial tone

Question 7

What are some leukotriene (mostly LTC4, LTD4, LTE4) receptor anatagonists?

Answer 7

Montelukast (asthma tx), Zafirlukast

Question 8

What drugs inhibit COX1 and COX2?

Answer 8

Aspirin (irreversible)

NSAIDs (indomethacin, Ibuprofen, Naproxen, Ketorlac, Diclofenac)

Question 9

What is an exclusive COX-2 inhibitor?

Answer 9

Celecoxib

Question 10

What does PGI2 do?

Answer 10

decrease platelet aggregation and vascular tone (inhibitor= epoprostenol)

Question 11

What does PGE1 do?

Answer 11

decrease vascular tone (inhibitor= alprostadil)

Question 12

What does PGE2 and PGF2 do?

Answer 12

increase uterine tone (inhibitor PGE2= dinoprostone; inhibitor PGF2= carboprost)

Question 13

What does acetominophen (Tylenol) do?

Answer 13

reversibly inhibit COX, mostly in the CNS. Inactivated peripherally

Question 14

What are the uses of Tylenol?

Answer 14

antipyreitc, analgesic, but NOT anti-inflammatory

Viral infections in children (do not use Aspirin; Reyes syndrome)

Question 15

What are the AEs of acetaminophen?

Answer 15

hepatic necrosis in overdose due to accumulation of NAPQI (antidote= N-acetylcysteine)

Question 16

How does aspirin work?

Answer 16

irreversibly inhibits COX1 and COX2 via acetylation, which decreases the synthesis of TXA2 and prostaglandins

Question 17

What effect does aspirin have on BT, PT, and PTT?

Answer 17

increased BT

no effect on PT or PTT

Question 18

What are the uses of aspirin?

Answer 18

Low dose (less than 300mg/day): decrease platelet agg

Medium dose (300-2400mg/day): antipyretic and analgesic

High dose (2400-4000mg/day): anti-inflammatory

Question 19

What are the AEs of aspirin?

Answer 19

gastric ulceration

tinnitus

chronic use can lead to acute renal failure, interstitial nephritis, GI bleeding

Reyes syndrome in children

Question 20

What effect does aspirin have on pH?

Answer 20

causes respiratory alkalosis early, but transitions to mixed metabolic acidosis-respiratory alkalosis

Question 21

What advantage does Celecoxib have?

Answer 21

it reversibly inhibits specifically COX2, which is found in inflammatory cells and vascular endothelium and mediates inflammation and pain but spares COX-1, which helps maintain gastric mucosa. Thus, does not have the corrosive effects of other NSAIDs on the GI lining.

Also spares the function of TXA2 (plateley aggregator)

Question 22

What are the main uses of celecoxib?

Answer 22

rheumatoid arthritis and osteoarthritis

Question 23

What are the AEs of celecoxib?

Answer 23

risk of thrombosis and sulfa allergy

Question 24

What are the AEs of NSAIDs (e.g. Indomethacin, naproxen, ibuprofen)?

Answer 24

interstitial nephritis, gastric ulcer, renal ischemia

Question 25

What is Aledronate?

Answer 25

a bisphosphonate, a pyrophosphate analog that binds hydroxyapatite in bone, inhibiting osteoclast activity for tx of osteoporosis, hypercalcemia, and Paget disease of bone

Question 26

What are the main AEs of bisphosphonates?

Answer 26

corrosive esophagitis, jaw osteonecrosis

Question 27

What is Teriparatide?

Answer 27

rcombinant PTH analog given subQ daily to increase osteoblastic activity for tx of osteoporosis

Question 28

What are the drugs used for tx of chronic gout (preventative)?

Answer 28

-allopurinol, febuxostat, pegloticase, and probenecid

Question 29

What does allopurinol do?

Answer 29

inhibits xanthine oxidase after being converted to alloxanthine, and decreases conversion of xanthine to uric acid

Question 30

What is another use of allopurinol?

Answer 30

lymphoma and leukemia to prevent TLS associated urate nephropathy

Question 31

Allopurinol increases the conc of what drugs?

Answer 31

azathiopurine and 6-MP (both normally metabolizes by xanthine oxidase)

Question 32

What does feboxustat do?

Answer 32

inhibit xanthine oxidase

Question 33

What is Pegloticase?

Answer 33

a recombinant uriace that catalyzes the metabolism of uric acid to allantion (a more water soluble product)

Question 34

How does probenecid help in gout tx?

Answer 34

it inhibits reabsorption of uric acid in the proximal convoluted tubules (also inhibits secretion of penicillin)

Question 35

How is an acute gout attack tx?

Answer 35

NSAIDs, steroids, and colchicine

Question 36

What are the main NSAIDs used for gout tx?

Answer 36

indomethacine and naproxen

Question 37

How does colchicine work?

Answer 37

It binds and stabilizes tubulin to inhibit microtubules polymerization, impairing neutrophil chemotaxis and degranulation