Chapter 57- Antacids Flashcards

1
Q

Antacids-Generic Medications

A

Sodium bicarb (Bell-ans)
Calcium carbonate (Osytercal, Tums)
Magnesium salts (Milk of Magnesia)
Aluminum salts (Amphojel)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Antacids-MOA

A

Antacids neutralize stomach acid by direct chemical reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Antacids-Sodium Bicarb
(oldest drug in this group)

A

Readily available in many preparations, including baking soda powder, tablets, solutions, and as an injectable for treating systemic acidosis.

This drug is widely distributed when absorbed orally, reaching peak levels in 1-3hr, crossing the placenta, and entering breast milk.

Excreted in the urine

Can cause serious electrolyte imbalance in people with renal impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Antacids-Calcium carbonate

A

Precipitated chalk and is available in tablet and powder forms

The main drawbacks are constipation and acid rebound.

Onset of action is about 3-5min

It can be absorbed systemically and cause calcium imbalance

When absorbed, it is metabolized in the liver

Excreted in the urine and feces

Known to cross the placenta and enter breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Antacids-Magnesium salts

A

Effective in buffering acid in the stomach but have been known to cause diarrhea; sometimes used as laxatives.

Available as tablets, chewable, tablets, capsules, and liquid forms.

Although not absorbed systemically, magnesium can lead to nerve damage and even coma if absorbed systemically

Excreted in the feces, but excreted in the urine if absorbed systemically.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Antacids-Aluminum salts

A

Available as tablets, capsules, suspensions, and liquid form.

Do not cause acid rebound but are not very effective in neutralizing acid.

Bound in the feces for excretion

Related to severe constipation

Binds dietary phosphates and causes hypophosphatemia, which can then cause a calcium imbalance throughout the system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Antacids-Contraindications & cautions

A

Caution should be used in the following instances:
Any condition that can be exacerbated by electrolyte or acid-base imbalance

GI obstruction- Could cause systemic absorption of the drug

Renal dysfunction

Pregnancy and lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Antacids-Adverse effects

A

Frequent administration can cause acid rebound, in which the stomach produces more acid in response to the alkaline environment

In many cases, acid rebound causes an increase in symptoms, which results in an increased intake of the antacid. The more frequent administration, the higher the incidence of systemic effects. Alkalosis with resultant metabolic changes (N/V, neuromuscular changes, headache, irritability, muscle twitching, and even coma) may occur.

Calcium salts may lead to hypercalcemia and milk-alkali syndrome (seen as alkalosis, renal calcium deposits, or severe electrolyte disorders)

Constipation or diarrhea may occur depending on the antacid being used

Hypophosphatemia can occur with the use of aluminum salts

Fluid retention and heart failure can occur with sodium bicarb because of the high sodium content.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Antacids-Drug to drug interactions

A

Because most drugs are prepared for an acidic environment, an alkaline environment can prevent them from being broken down for absorption, or can render them neutralized so they cant be absorbed. Patients taking antacids should take them 2 hr before/after any other medication

If the pH of the urine is affected by large doses of antacids, the levels of drugs such as quinidine may increase and the levels of salicylates may decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sodium Bicarb-Antacid Prototype

A

Adjunctive treatment of severe diarrhea

Also used for the treatment of metabolic acidosis (IV form)

May also be used to treat certain drug intoxication to minimize the uric acid
crystallization

Adverse effects:
Gastric rupture, systemic alkalosis (headache, nausea, irritability, weakness, tetany, confusion) hypokalemia (secondary to intracellular shifting of potassium, and gastric acid rebound)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Antacids- Pre/post medication assessment

A

Monitor lab test results, including serum electrolyte levels and renal function

Give 1hr before, or 2hr after any other oral medications

Monitor for S/S of acid-base imbalance or electrolyte imbalance

Monitor for diarrhea or constipation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly