Gout Flashcards Preview

4Qpharm3-test1 > Gout > Flashcards

Flashcards in Gout Deck (19):
1

What is gout?
Describe the two types

Gout is a dz caused by an ↑ in the amt of uric acid in the body

OVERPRODUCERS of uric acid: (U) excrete 1g uric acid/day in urine & have larger body pool of uric acid (as in polycythemia vera, myeloid metaplasia, leukemia or lymphoma)

UNDEREXCRETORS: renal excretion of uric acid is somehow low (as in lead neuropathy, glycogen-storage dz, sickle cell dz)

2

2 objectives in tx of gout & their meds:

TERMINATE INFLAMMATORY PROCESS of acute attack w/colchicine, indomethacin & other anti-inflammatory agents

↓HYPERURICEMIA: to prevent the formation of urate deposits & acute attacks of gouty arthritis & to promote resolution of tophi w/URICOSURIC AGENTS that↓ pool of uric acid in tophacious gout & 2*hyperuricemia (probenecid & sulfinapyrazone) & by allopurinol (↓formation of uric acid)

3

Colchicine is only effective against what?

only effective against gouty arthritis (is a unique anti-inflammatory agent)

↓ pain & inflammation of an ACUTE ATTACK & is also an effective prophylactic agent against acute attacks

4

Colchicine effects

NO ANALGESIC EFFECT, NO EFFECT on COX enzymes, NO effect on urate excretion

-binds to tubulin; inhibits assembly of microtubules (this causes SEs)
-anti-inflammatory effects due to inhibiting leukocyte migration & phagocytosis
-inhibits formation of leukotriene B4

5

Cochicine: admin, effective when, AWs

ORAL admin (IV:increased toxicity)
effective in 12-24 hrs
AEs: DIARRHEA, N/V, abdominal pain

6

NSAIDs used in gout

very effective for inflammation a/w gouty arthritis
-INDOMETHACIN is primary NSAID used in gout tx
-NAPROXEN & sulindac are often used
-specific reversible inhibitors of COX-2 enzymes

7

NSAIDs CONTRAINDICATED in gout

ASPIRIN, SALICYLATES are contraindicated b/c they ↓ urate excretion!!!

8

Uricosuric agents (Probenecid): how do they work?

BLOCK THE ACTIVE REABSORPTION OF URIC ACID in proximal tubule (↑ urinary excretion of uric acid)

-ineffective in acute attacks, and may aggravate the sxs

9

Uricosuric agents (Probenecid): what must be done during tx

-maintain large urine volume to minimize pos of KINDEY STONE formation
-keep urine pH>6.0 (alkali administration)
-PROPHYLACTIC COLCHICINE THERAY may be needed as initial admin may trigger couty attack

10

Uricosuric agent (Probenecid) SE

GI irritation

11

What is the only uricosuric agent on the market today?

Probenecid

12

Probenecid: use, admin, interactions, SE

increases excretion of uric acid (gout)
ORAL admin
start tx 2-3 weeks AFTER an acute attack
-↓excretion of many acidic compounds or metabolites (most imp: PENICILLIN, others: methotrexate, clofibrate, glucuronides of NSAIDs etc)

13

Allopurinol (Zyloprim): class, use effects

xanthine oxidase inhibitor (inhibits synthesis of uric acid)

effective in both 1* & 2* forms of gout

serious SEs can occur, including vasculitis, agranulocytosis & hypersensitivity rxns

initial therapy MAY PROVOKE ACUTE GOUTY ATTACK, colchicine prophylaxis may be necessary

14

Febuxostate (Uloric): class, use, effects

xanthine oxidase inhibitor (inhibits synthesis of uric acid)

effective in both 1* & 2* forms of gout

serious SEs can occur, including vasculitis, agranulocytosis & hypersensitivity rxns

initial therapy MAY PROVOKE ACUTE GOUTY ATTACK, colchicine prophylaxis may be necessary

15

Allopurinol (Zyloprim) & Febuxostat (Uloric): class & intrxns

allopurinol & Febuxostat are xanthine oxidase inhibitors
drug intxns:
-ALUMINUM HYDROXIDE ↓ ABSORPTION of allopurinol
-↑ effect of MERCAPTOPURINES (6-MP) & azathioprine [both anti-CA agents]
-↑effect of CYCLOPHOSPHAMIDE
-inhibits elimination of CHLORPROPAMIDE
-inhibits metabolism of WARFARIN & PROBENECID
-inhibits activation of FLUOROURACIL (5-FU), reducing its therapeutic effect

16

What is the enzyme that converts uric acid to allantoin?

Rasburicase (Fasturtec)

17

Rasburicase: what is it, effects

RECOMBINANT FORM OF URATE OXIDASE, NOT endogenous in humans
-it catalyzes enzymatic oxidation of uric acid into a readily excreted metabolite, allantois, thus lowering serum uric acid levels
-effective in tx pediatric pts w/hematologic malignancies or hyperuricemia

18

Rasburicase: route of admin, adverse rxns

administered by IV infusion
AE: severe hypersensitivity rxns incl. anaphylactic shock & anaphylactoid rxns
N/V, fever, HA, abd. pain, constipation, diarrhea

19

What meds are contraindicated in gout

every drug that is ACIDIC can DECREASE THE EXCRETION OF URIC ACID
(acidic meds include: ASA, ethambutol, furosemide, niacin, etc.)