Med chem: antacids & H2RAs (1-17)

Antacids are ____.

• weak bases

• strong bases

What is the primary mechanism of antacids?

• inhibit proton pump

• neutralize the stomach acid that is already there.

Antacids prevent acid over production as well as neutralizes acid already present in the stomach.

• True

• False

Answer explanation

Antacids DO NOT prevent acid over production

Secondary mechanisms of antacids:

• promote gastric mucosal defenses

• secretion of mucus

• secretion of bicarb

• secretion of prostaglandins

match

• secretion of bicarb

• protective barrier against HCl

• prostaglandins

• prevents activation of proton pump

• secretion of mucus

• helps buffer acidic properties of HCl

Raising gastric pH from 1.3 to 1.6 neutralizes ___ of gastric acid

• 90%

• 50%

Raising gastric pH a single point from 1.3 to 2.3 neutralizes ___ of the gastric acid.

• 90%

• 50%

What are the by products of sodium bicarb? (NaHCO3)

• NaCl

• CO3

Answer explanation

CO3 goes on to react with water to give CO2.

CO2=gas=belching

Which is a better antacid?

• NaHCO3

• Al(OH)3

Answer explanation

Al(OH)3 does not produce a gas and sodium bicarb does. So there is no gas production.

What type of antacid can commonly cause laxative effects?

• magnesium salts

• calcium salts

Answer explanation

magnesium carbonate, hydroxide, oxide, trisilicate