Hyperuricemia & Gout Pharm

Question 1

Colchicine

Answer 1

Prophylactic against attacks of gouty arthritis & termination of acute attacks.
Breaks down microtubules to prevent mitosis & affects neutrophil function & motility

Question 2

Side effects of colchicine

Answer 2

Dose-related GI disturbances, blood dyscrasias (chronic)
Impaired renal & hepatic function → ↑ toxicity. Myopathy, peripheral neuropathy, rhabdomyolysis.
Monitor with CBC, serum alk phos.

Question 3

Indomethacine

Answer 3

Treats acute gout attacks

COX inhibitor, analgesic, antipyretic, inhibits leukocyte motility

Question 4

Side effects of indomethacine

Answer 4

N/V, ulcers - take with antacid
CNS - severe frontal HA
Hematopoietic disorders
Antagonizes furosemide & HCTZ

Question 5

Allopurinol

Answer 5

Competitive inhibitor of xanthine oxidase, and metabolized to oxypurinol that is a non-competitive inhibitor of xanthine oxidase. Prevents conversion from hypoxanthine to xanthine.
↑ excretion of precursors, prevents formation of uric acid kidney stones, allows for dissolution of crystals

Question 6

Side effects of allopurinol

Answer 6

↑ incidence of acute gout, hypersensitivity skin rxns, affects liver function, reduce dose with renal insufficiency.
Interacts with 6-MP
Contraindicated with ampicillin and others

Question 7

Febuxostat

Answer 7

Inhibits xanthine oxidase irreversibly. Similar action to allopurinol.

Question 8

Reasons to use febuxostat over allopurinol

Answer 8

More potent with less side effects.
For hypersensitivity to allopurinol.
In pts with renal impairment

Question 9

Side effects of febuxostat

Answer 9

Mild. Rare elevation of LFTs.

Question 10

Probenecid

Answer 10

Uricosuric agent.
Inhibits transport of organic anions across epithelium - interferes with post-secretory uric acid reabsorption in proximal tubule.
Used for pts who excrete < 1 g/day. Req. good hydration

Question 11

Side effects of probenecid

Answer 11

Action inhibited by salicylates, diuretics

Question 12

Pegloticase

Answer 12

IV infusion, pegylated for long half life.
Urate oxidase analog that breaks down urate to allantoin. Allantoin is easily excreted in urine.
Rapidly lowers serum levels of uric acid and decreases urinary acid excretion. Rapidly dissolves tophi.

Question 13

Side effects of pegloticase

Answer 13

Gout flares with dissolution of tophi. Prophylactic colchicine, NSAIDs.
Can develop Abs to PEG.
Very expensive.