Beevers GI drugs

Question 1

Acid-peptic disorder therapy drugs are divided into what two main classes?

Answer 1

• agents that reduce intragastric acidity

- agents that promote mucosal defense

Question 2

Weak bases will react with HCl to from what?

Answer 2

salt and water

Question 3

What are antacids?

Answer 3

Inorganic compounds that function as wea bases

Question 4

What is the mechanism of action of anacids?

Answer 4

As weak bases, they react with gastric hydrochloric acid (HCl) to form a salt and water

Question 5

Give examples of antacids.

Answer 5

1. Sodium bicarbonate
2. CaCO3
3. MgOH2
4. AlOH3 2

Question 6

What are the products of sodium bicarb plus hydrogen?

Answer 6

water and CO2 and NaCl

Question 7

Sodium bicarbonate

Answer 7

-antacid
-Reacts RAPIDLY with HCl to produce CO2 and NaCl
ADVERSE EFFECTS:Gastric distention and belching (due to CO2 formation), metabolic alkalosis (from rapid absorption of unreacted alkali), fluid retention (due to NaCl absorption; usually occurs in patients with heart failure, hypertension, and renal insufficiency)
CONTRAINDICATIONS:
1. Hypochloremia, alkalosis, excessive doses with calcium-containing dairy products (may cause hypercalcemia, renal insufficiency, and metabolic alkalosis; known as milk-alkali syndrome)
2. Pregnancy/Lactation—Category C/precaution (safety unknown)

Question 8

Calcium carbonate

Answer 8

-antacid
-Reacts SLOWLY with HCl to produce CO2 and CaCl2
ADVERSE EFFECTS: Hypercalcemia, nephrolithiasis, milk-alkali syndrome (see below), hypercalciuria, hypomagnesemia, constipation, nausea
CONTRAINDICATIONS:
1. Hypophosphatemia, nephrolithiasis, hypercalcemia, excessive doses with calcium-containing dairy products (milk-alkali syndrome)
2. Pregnancy/Lactation—Category C/precaution (probably safe)

Question 9

Magnesium hydroxide

Answer 9

-antacid
- Reacts SLOWLY with HCl to produce MgCl2 and water
- Usually co-administered with aluminum hydroxide
ADVERSE EFFECTS: Osmotic diarrhea (caused by unabsorbed magnesium salts; co-administration of aluminum hydroxide with magnesium hydroxide minimizes the overall net effect on bowel function), hypermagnesemia, abdominal pain, dehydration, nausea/vomiting
CONTRAINDICATIONS:
1. Colostomy, ileostomy, renal failure
2. Pregnancy/Lactation—Category B/safe

Question 10

Aluminu hydroxide

Answer 10

• Reacts SLOWLY with HCl to produce AlCl3 and water
• Usually co-administered with magnesium hydroxide
  ADVERSE EFFECTS: Constipation (caused by unabsorbed aluminum salts; co-administration of aluminum hydroxide with magnesium hydroxide minimizes the overall net effect on bowel function), aluminum intoxication, encephalopathy, osteomalacia, hypophosphatemia, abdominal pain
  CONTRAINDICATIONS:
  1. GI obstruction, pregnancy (high doses)
  2. Drug combinations
  o Sodium citrate/citric acid
  3. Pregnancy/Lactation—Category B/precaution (probably safe)

Question 11

Name the drug class: Cimetidine

Answer 11

H2 receptor antagonist

Question 12

Name the drug class: Famotidine

Answer 12

H2 receptor antagonist

Question 13

Name the drug class: Nizatidine

Answer 13

H2 receptor antagonist

Question 14

Name the drug class: Ranitidine

Answer 14

H2 receptor antagonist