Drugs for Gout

Question 1

Why take NSAID or Colchicine while taking Allopurinol?

Answer 1

-allopurinol has the paradoxical effect of inducing an acute gout attack.

Question 1

why is probenecid contraindicated in pts with kidney disease or are overproducers of uric acid?

Answer 1

they are more likely with probenecid to produce uric acid stones in their kidney

Question 1

this gout drug has interactions with 6-MP and azathioprine. why?

Answer 1

Allopurinol.

-as a xanthase oxidase inhibitor, it inhibits purine metabolism. 6-MP (azathioprine is its produg) is a purine analog, so allopurinol increases risk of 6-MP toxicity.

Question 3

Colchicine:

-side effects

Answer 3

• GI symptoms! nausea, vomiting, diarrhea, pain.
• occurs because rapidly growing GI cells are affected

Question 3

Allopurinol

-theurapeutic use

Answer 3

-prevent primary hyperurecemia of chronic gout

Question 4

probenecid,

therapeutic use

Answer 4

• chronic gout
• however, not in pts with kidney disease or overproducers of uric acid because they are more likely to produce uric acid stones in the kidney

Question 6

When would you use steroid over NSAID in gout patient?

Answer 6

When NSAIDS are contraindicated in the patient (eg stomach ulcers)

Question 6

Pegloticase

-mech

Answer 6

• uricase
• converts uric acid to allantoin, which is excreted.

Question 7

pegloticase

-therapeutic use

Answer 7

• refractory chronic gout
• limited use

Question 8

Colchicine:

-why do certain drugs interact with it?

Answer 8

1. active form is metabolized by CYP3A4
2. it is a substrate for P-glycoprotein pump
   - drugs that interact with either will increase colchicine to toxic levels.

Question 9

If your patient presents with gout, what 2 common drugs he might already be using do you tell him to stop taking?

and why?

Answer 9

1. aspirin (low doses decrease renal urate excretion)
2. HCTZ (thiazaide diuretics decrease renal urate excretion)

Question 10

Colchicine:

-therapeutic uses (2)

Answer 10

• decreases inflammation
  1. acute gout attacks (use within hours)
  2. chronic gout prophylaxis

Question 11

pegloticase

-adverse effects (3)

Answer 11

• infusion site reactions
• gout flare
• immune response: body may make Ab against PEG porion of drug

Question 12

This gout drug is metabolized by P450 and p-glycoprotein

Answer 12

colchicine.

So, drugs that block CYP3A4 or P-gp transport can increase colchicine to toxic levels

Question 13

Why is colchicine not the drug of choice in tx of gout?

Answer 13

Strong adverse GI effects

Question 15

Why is aspirin contraindicated in gout?

Answer 15

At low doses, aspirin inhibits uric acid secretion

Question 17

Colchicine

-mech

Answer 17

• antimitotic–arrests cell in G1 by interfering with microtubule formation
• in gout, colchicine binds to microtubules in neutrophils, inhibiting their activation/migration and inflammatory response

Question 18

probenecid

-mech

Answer 18

• increases renal urate excretion
• OAT blocker
• competes with OAT (which normally reabsorbs urate)

Question 19

probenecid

• side effects
• contraindications

Answer 19

• GI effects
• ineffective in pts with renal sufficiency
• contraindicated in pt with uric acid kidney stones

Question 20

Allopurinol

-adverse effects

Answer 20

1. hypersensitivity
2. acute gout attack (paradoxical!)–allopurinol mobilizes tissue stores of uric acid. So, give drug with NSAID or colchicine

Question 21

Allopurinol

-mech

Answer 21

• inhibits terminal steps in uric acid synthesis
• blocks xanthine oxidase

Question 22

Febuxostat

-mech

Answer 22

• xanthine oxidase inhibitor, just like allopurinol
• more potent than allopurinol