KG - Pharm 3, Exam 1, Gout

Question 1

what is gout?

Answer 1

dz caused by increase in amt of uric acid in body

Question 2

gout - overproducers?

Answer 2

• excrete 1 g uric acid/day in urine
• have larger body pool uric acid

(ie: as in polycythemia vera, myeloid metaplasia, leukemia, lymphoma)

Question 3

gout - underexcreters?

Answer 3

• renal excretion of uric acid = low

ie: as in lead neuropathy, glycogen storage dz, sickle cell

Question 4

2 goals of gout tx?

Answer 4

1. terminate inflammatory process of acute attack

2. reduce hyperuricemia to prevent formation of irate deposits and acute attacks

Question 5

why acute attacks gout?

Answer 5

• follow deposition of usic acid crystals in peripheral joints
• crystals PHAGOCYTOSED, initiates inflammatory rxn (mediated by PGs & cells immune system)
• inflammatory causes pain

Question 6

Colchicine: info

Answer 6

• NO ANALGESIC EFFECT
• no effect on COX enzyme
• BINDS TO TUBULIN, inhibits assembly microtubules
• INHIBITS LEUKOCYTE MIGRATION & PHAGOCYTOSIS

Question 7

Colchicine: when to use?

Answer 7

• used to reduce pain in ACUTE ATTACK

Question 8

Colchicine: pharmacokinetics

Answer 8

• admin = ORAL

- effective in 12-24 hrs (need NSAID meantime)

Question 9

Colchicine: adverse effects

Answer 9

• DIARRHEA!!!
• N/V
• abd pain

Question 10

which NSAID used as primary NSAID for tx gout?

Answer 10

Indomethacin

also naproxen, Sulindac

Question 11

which NSAIDS contraindicated in tx gout?

Answer 11

• ASPIRIN, SALICYLATES

decr urate excretion

Question 12

uricosuric agents: moa

Answer 12

• increase excretion uric acid by BLOCKING ACTIVE REABSORPTION OF URIC ACID in proximal tubule
• must maintain large urine volume (prevent kidney stone formation)

Question 13

What to be aware of when initiated tx uricosuric agents?

Answer 13

• initial admin may trigger gouty attack, may need prophylactic colchicine
• NOT effective in acute attacks

Question 14

uricosuric agents: side effects

Answer 14

GI IRRITATION

Question 15

probenicid: info

Answer 15

• admin = oral
• start 2-3 weeks after attack
• decrease excretion of acidic compound/metabolites (ie: PCN, methotrexate, clofibrate, glucoronides, etc…)

Question 16

Allopurinol/Febuxostat: info

Answer 16

• INHIBIT XANTHINE OXIDASE (INHIBIT SYNTHESIS OF URIC ACID)

- for primary/secondary forms gout

Question 17

Allopurinol/Febuxostat: side effects

Answer 17

• vasculitis
• agranulocytosis
• hypersensitivity rxns

Question 18

Allopurinol/Febuxostat: what to keep in mind when initiating tx?

Answer 18

• initial tx may provoke acute gouty attack

- sue colchicine prophylaxis

Question 19

Allopurinol/Febuxostat: drug interactions

Answer 19

• **alluminum hydroxide = decr absorption allopurinol
• **increase effect chemotherapeutic 6-MP/Imuran
• **inhibit activation 5-FU (reducing therapeutic effect)
• inhibit metabolism warfarin, probenicid
• inhibit elimination chlorpropamide
• increase effet clyclophosphamide

Question 20

Rasburicase: moa

Answer 20

• ENZYME CONVERTING URIC ACID TO ALLANTOIN
• RECOMBINANT FORM OF URATE OXIDASE
• catalyzes oxidation of uric acid to excreted metabolite - lowering serum uric acid levels
• URATE OXIDASE is NOT endogenous in humans!!!

Question 21

what patients are at high risk for tumor lysis syndrome (and thus hyperuricemia)?

Answer 21

• pts w/ hematological malignancies or solid tumors

- esp post-chemo

Question 22

Rasburicase: pharmacokinetics

Answer 22

• admin = IV

Question 23

Rasburicase: adverse rxns

Answer 23

• severe hypersensitivity incl anaphylaxis

- N/V, fever, HA, abd pain, constipation, diarrhea