Pre-Operative Antacids

Question 1

What is the normal dosage of Na⁺ Citrate (Bicitra)

Answer 1

15 - 30 mls

Question 2

How does Bicitra work?

Answer 2

Non-particulate neutralization of gastric pH

Question 3

What is the downside of Bicitra (Sodium Citrate)?

Answer 3

• ↑ Na⁺
• ↑ gastric volume
• ↑ gastric pH

-Note: Sodium citrate = non-particulate antacid

Question 4

What are the H₂ antagonists used in the operating room?

Answer 4

-Cimetidine (Tagamet)
-Ranitidine (Zantac)
-Famotidine (Pepcid)

Question 5

What is the most potent H₂ antagonist?

Answer 5

Famotidine

Question 6

What is the dose of Famotidine?

Answer 6

20 mg IV
(1/2 dose for renal failure)

Question 7

What is a major downside to famotidine usage?

Answer 7

Inhibition of phosphate absorption → hypophosphatemia

Question 8

What is the major downside to cimetidine use?

Answer 8

CYP450 inhibition

Consider warfarin, phenytoin, TCA’s, propranolol, nifedipine, meperidine, diazepam

Question 9

What is the dose of cimetidine?

Answer 9

150 - 300 mg IV

Question 10

What is the dose of Ranitidine?

Answer 10

50mg/20mls over 2 min
(1/2 dose for renal impairment)

Question 11

What effects do PPI’s have on anticoagulants?

Answer 11

• Inhibits warfarin metabolism = ↑ INR
• Blocks enzyme that activates clopedigrel (Plavix) = ↓ antiplatelet function of Plavix

Question 12

What is the IV dose of pantoprazole?

Answer 12

40 mg / 100 mls over 2 min

Question 13

What is the IV dose of omeprazole?

Answer 13

40 mg / 100mls over 30 min

Question 14

What is the PO dose of omeprazole?

Answer 14

40 mg → 3 hours prior to surgery