ANTACIDS Flashcards
_______ is secreted from parietal cells when stimulated by the vagus nerve, histamine, and gastrin. CO2 and H2O
react inside parietal cells, under the influence of carbonic anhydrase, to form bicarbonate (HCO3
–) and H+
Gastric acid
is also secreted from parietal cells into the lumen by simple diffusion.
Cl−
_______ is then pumped into the lumen of the stomach by H+/K+ ATPase.
H+
H+, Cl− and water combine in the lumen to form ______
hydrochloric acid (HCl)
_______ produced is secreted into the bloodstream
HCO3–
_______ are weak alkaline compounds used to neutralize hydrochloric acid in the
stomach
Antacid
________ are the substances which reduce gastric acidity resulting in an increase in the pH of stomach and duodenum
Antacids
______ occurs due to excessive secretion of HCl in stomach due to various reasons
Gastric Acidity
The pH of the stomach is _______ when empty
1.5- 2.5
The pH of the stomach raises to ______ when food is ingested.
5-6
_____ is due to the presence of endogenous HCl, which is always present under physiological conditions.
Low pH
When hyperacidity occurs the result can range from:
i. Gastritis (a general inflammation of gastric mucosa)
ii. Peptic ulcer or oesophageal ulcer (lower end of oesophagus)
iii. Gastric ulcer (stomach)
iv. Duodenum ulcers
Symptom of hyperacidity:
Hydrochloric acid is secreted by the stomach to kill harmful organisms, aid digestion and activate digestive
enzymes.
Excess secretion of acid into stomach or impaired resistance by the lining of the stomach or reflux into the
oesophagus may produce symptoms.
Hyperacidity cause gastric reflux, gastritis, upset stomach and heartburn.
______ is secreted by the stomach to kill harmful organisms, aid digestion and activate digestive
enzymes.
Hydrochloric acid
_____ cause gastric reflux, gastritis, upset stomach and heartburn.
Hyperacidity
The antacid should buffer in the _____
pH 4-6 range
Criteria of an ideal antacid preparation:
The antacid should not be absorbable or cause systemic alkalosis
The antacid should not be a laxative or causes constipation
The antacid should exert its effect rapidly and over a long period of time
The antacid should buffer in the pH 4-6 range
The reaction of the antacid with gastric HCl acid should not cause a large evolution of gas
The antacid should probably inhibit pepsin
_____ show the most rapid onset of action and provide faster relief of symptoms.
Absorbable Antacids
Absorbable Antacids inappropriate for patients afflicted with ________
hypertension or kidney failure
less prone to cause a rebound effect
Non-Absorbable Antacids
______ are more potent and
effective in a semi liquid or liquid form than in a capsule or table
Non-Adsorbable Antacids
The usually high presence of _____ and _____ in non-absorbable antacids can be effectively used to prevent significant stress ulcer bleeding in post-operative patients or those with severe burns.
aluminum and magnesium hydroxides
_____ are compounds that are not
absorbed into the systemic circulation.
Non-systemic antacids
These agents do not produce metabolic
alkalosis.
Non-systemic Antacids
Their anionic group neutralizes the H+ ions in gastric acid. This releases their cationic group which combines with HCO3– from the pancreas to form an insoluble basic compound that is excreted in feces.
Non-systemic Antacids
______ are absorbed into the systemic
circulation.
Systemic Antacids
They have a cationic group that does not form insoluble basic compounds with HCO3–.
Systemic Antacids
Non-absorbable antacids have many others favorable properties:
Absorb pepsin, resulting in reduced proteolytic activity of gastric acid.
Connect lysolecithin and bile acid, which have a damaging effect on the gastric mucosa.
Possess cytoprotective function through the activation of prostaglandin synthesis, which stimulate a secretion
of mucin and bicarbonates, improve microcirculation.
Possess ambient function, forming a protective film on the gastric mucosal surface.
Able to bind epithelial growth factor and fix it in the ulcerous defect region effectively stimulating cell
proliferation, angenesis and angiogenesis.
Antacids are used in the intensive care units to prevent so-called _______.
stress ulcers
To avoide undesirable interactions with other drugs, antacids are usually used ______ taking any medication.
2 hours before or after
NaHCO3
Sodium Bicarbonate
appearance, odor, and taste of Sodium Bicarbonate
white crystalline pow(d)er or granules; odorless; saline taste
Above 50 degrees celsius, sodium bicarbonate gradually decomposes into ______.
Sodium Carbonate
_____ can also be useful in removing splinters from the skin.
Bicarbonate of soda
high doses of sodium bicarbonate causes:
headache, nausea or irritablity
Symptoms of Alkalosis or metabolic alkalosis:
• Confusion(can progress to stupor or coma)
• Hand tremor
• Light-headedness
• Muscle twitching
• Nausea, vomiting
• Prolonged muscle spasms (tetany)
Aluminum Hydroxide gel chemical formula
Al(OH)3
appearance, odor, taste of Aluminum Hydroxide gel
white amorphous powder; odorless; tasteless
Aluminum hydroxide is ______ in nature.
Amphoteric
____ use in the tx of GERD.
Aluminum hydroxide
______ is a condition caused by gastrin-secreting pancreatic adenomas that lead to multiple ulcers in the stomach and duodenum.
Zollinger-Ellison Syndrome
_____ is a sensation of pain or discomfort in the upper abdomen.
Dyspepsia
______ softening of the bones, typically through a deficiency of vitamin D or calcium.
Osteomalacia
_____ is a disease where increased bone weakness increases the risk of a broken bone.
Osteoporosis
Magnesium hydroxide chemical formula
Mg(OH)2
appearance, odor, and taste of Magnesium hydroxide
white amorphous powder; odorless; tasteless
______ is effective in relieving heartburn, but it is infrequently used to treat peptic ulcers or GERD.
Calcium carbonate
_____ is a suspension of Magnesium Hydroxide.
Milk of Magnesia
•used for a short time to treat occasional constipation, it is used as Laxative.
•also used to treat symptoms caused by too much stomach acid such as heartburn, upset stomach or indigestion.
Milk of Magnesia
is a weak and slow reacting antacid.
Aluminum hydroxide
is a potent antacid with rapid acid neutralizing capacity, but on long term use, it can cause hypercalcemia, hypercalciuria and formation of calcium stone in kidney.
calcium carbonate
containing preparation e.g. ________ a fast acting antacid with __________ which is a slow acting antacid.
Magnesium hydroxide and Aluminum hydroxide
containing preparation where one is laxative and the later one is constipative in nature.
Magnesium and Calcium
