Chapter 50 Acid-controlling drugs

Question 1

Antacids are basic compounds used to neutralize stomach acid. Most commonly they are?

Answer 1

nonprescription salts of aluminum, magnesium, calcium, and/or sodium.

Question 2

Many antacid preparations contain the antiflatulent drug?

Answer 2

simethicone, which reduces gas and bloating

Question 3

Many aluminum- and calcium-based formulations also

include?

Answer 3

magnesium, which not only contributes to the acid neutralizing capacity, but also counteracts the constipating effects of aluminum and calcium.

Question 4

Antacids (Calcium carbonate [tums], magnesium hydroxide [milk of magnesia]) MOA

Answer 4

neutralizing gastric acidity. They do not prevent the overproduction of acid but instead help to neutralize acid secretions. It is also believed that antacids promote gastric mucosal defensive mechanisms, especially at lower dosages.

• They do this by stimulating secretion of mucus, prostaglandins, and bicarbonate from cells inside gastric glands
• mucus serves a protective barrier against destructive actions of hydrochloric acid
• bicarbonate helps buffer acidity of hydrochloric acid
• prostaglandins prevent histamine from binding to its corresponding parietal cell receptors, which inhibits production of adenylate cyclase. W/out adenlyate cyclase, no cAMP can be formed and no second messenger is available to activate proton pum

Question 5

The primary drug effect of antacids is?

Answer 5

reduction of the symptoms associated with various acid-related disorders, such as pain and reflux “heartburn”
-Antacid pain reduction is thought to be a result of base-mediated inhibition of the protein-digesting ability of pepsin, increase in the resistance of the stomach lining to irritation, and increase in the tone of the cardiac sphincter, which reduces reflux from the stomach

Question 6

Antacids indications

Answer 6

indicated for the acute relief of symptoms associated with peptic ulcer, gastritis, gastric hyperacidity, and heartburn

Question 7

Antacids contraindications

Answer 7

• known allergy to specific drug product
• severe renal failure or electrolyte disturbances (because of the potential toxic accumulation of electrolytes in the antacids themselves)
• GI obstruction (magnesium antacids may be contraindicated for pt’s with small bowel obstruction because of the laxative effect)

Question 8

Antacids adverse effects

Answer 8

Adverse effects are limited

• Magnesium preparations, such as milk of magnesia, can cause diarrhea.
• Aluminum- and calcium-containing formulations can cause constipation
• Calcium products can cause kidney stones; rebound hyperacidity, or acid rebound, when antacid use is discontinued; chronic use of high-dose calcium containing antacids or use in renal failure can cause a syndrome known as milk-alkali syndrome (HA, nausea, alkalosis, hypercalcemia)
• excessive use of any antacid can result in systemic alkalosis; more common with sodium bicarbonate

Question 9

long term self medication with antacids may?

Answer 9

mask symptoms of serious underlying disease such as bleeding ulcer or malignancy

Question 10

Antacids interactions

Answer 10

Many drug interactions occur with the acid-controlling drugs due to alteration of oral dosage forms, and so other medications are to be avoided within 1 to 2 hours of taking an antacid. Antacids are sometimes to be avoided when other acid-controlling drugs are taken.

Question 11

Combination products containing both magnesium and aluminum may have fewer adverse effects than either type of antacid by itself. The net effect is a?

Answer 11

balancing of both adverse effects and fewer problems with altered bowel patterns.

Question 12

Cautious use of antacids high in sodium is recommended in patients who have?

Answer 12

heart failure, hypertension, or other cardiac diseases or who require sodium restriction.

Question 13

Many drug interactions occur with the acid-controlling drugs due to alteration of oral dosage forms, and so other medications are to be avoided within?

Answer 13

1 to 2 hours of taking an antacid. Antacids are sometimes to be avoided when other acid-controlling drugs are taken.

Question 14

Four basic mechanisms by which antacids cause interactions include:

Answer 14

(1) adsorption of other drugs to antacids, which reduces the ability of the other drug to be absorbed into the body (2) chelation, which is the chemical inactivation of other drugs that produces insoluble complexes
(3) increased stomach pH, which increases the absorption of basic drugs and decreases the absorption of acidic drugs
(4) increased urinary pH, which increases the excretion of acidic drugs and decreases the excretion of basic drugs.

Question 15

Examples of drugs whose effects may be chemically enhanced by the presence of antacids (due to pH effects) are?

Answer 15

• Benzodiazepines
• Sulfonylureas
• Sympathomimetics
• Valprioic acid

Question 16

Presence of antacids reduces the efficacy of interacting drugs by?

Answer 16

Interfering with their GI absorption
-such drugs include: allopurinol, tetracycline, thyroid hormones, captopril, corticosteroids, digoxin, histamine antagonists, phenytoin, isoniazid, nitrofurantoin, phenothiazines, salicylates, and quinolone antibiotics

Question 17

Significant patient harm may ensue when the quinolone antibiotics (ciprofloxacin, levofloxacin, and moxifloxacin) are given with?

Answer 17

antacids
-these antibiotics are administered orally to treat serious infections. Antacids can reduce their absorption by more than 50%. Thus, antacids must be given either 2 hours before or 2 hours after the dose of a quinolone antibiotic

Question 18

Antacids are generally excreted quickly through the?

Answer 18

GI tract and/or the electrolyte homeostatic mechanisms of the kidneys

Question 19

Antacids are considered safe for use during pregnancy if?

Answer 19

Prolonged administration and high dosages are avoided

Question 20

Aluminum and sodium based antacids recommended for?

Answer 20

Patients with renal compromise because they are more easily excreted than antacids in other categories

Question 21

Calcium-containing antacids can be used as an extra?

Answer 21

Source of calcium

Question 22

Calcium carbonate neutralization will produce?

Answer 22

Gas and possibly belching

-for this reason it is combined w/an antiflatulent drug such as simethicone

Question 23

Magnesium-containing antacids commonly have a?

Answer 23

Laxative effect, and frequent administration of these antacids alone often cannot be tolerated

Question 24

Both calcium and magnesium antacids are more likely to accumulate?

Answer 24

To toxic levels in pt’s with renal disease and are often avoided in this patient group

Question 25

Some of the more serious concerns with antacids include?

Answer 25

acid rebound, hypercalcemia, milk-alkali syndrome, and metabolic alkalosis.

Question 26

H2 receptor antagonists, also known as H2RAs and H2 receptor blockers, are the prototypical acid-secretion antagonists. They are H2 blockers that bind to and block?

Answer 26

histamine receptors located on parietal cells. This blockade renders these cells less responsive to stimuli and thus decreases their acid secretion. Up to 90% inhibition of acid secretion can be achieved. -they competively block the H2 receptor of acid-producing parietal cells. This makes the parietal cell less responsive not only to histamine but also to the stimulation of ACh and gastrin

Question 27

H2 receptor antagonist drugs

Answer 27

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

Question 28

The effects of H2 receptor antagonists is

Answer 28

reduced hydrogen ion secretion from the parietal cells results in an increase in the stomach pH and relief of symptoms associated with hyperacidity-related conditions.

Question 29

H2 receptor antagonists indications

Answer 29

used for GERD, peptic ulcer disease, and erosive esophagitis; adjunct therapy in the control of upper GI tract bleeding; and treatment of pathologic gastric hypersecretory conditions such as Zollinger-Ellison syndrome.

Question 30

H2 receptor antagonists contraindications

Answer 30

- known drug allergy | - liver and/or kidney dysfunction are relative contraindications that my warrant dosage adjustment

Question 31

H2 receptor antagonists Adverse effects

Answer 31

- CNS AEs occur less than 1% of pt's but sometimes seen in older adults (confusion & disorientation) - Cimetidine (Tagamet) may induce impotence and gynecomastia (result of the drugs inhibition of estradiol metabolism and displacement of dihydrotestosterone from peripheral androgen-binding sites) - all 4 drugs may increase secretion of prolactin from the anterior pituitary gland - Thrombocytopenia has been reported with Ranitidine and Famotidine

Question 32

H2 receptor antagonists interactions

Answer 32

- Cimetidine carries a higher risk of drug interactions than ranitidine, famotidine, and nizatidine, especially in elderly. Cimetidine binds enzymes of the hepatic cytochrome P-450 microsomal oxidase system. By inhibiting the metabolism of drugs metabolized via this pathway, it may raise the blood concentrations of certain drugs. - Ranitidine has 10-20% of the binding action of cimetidine on the P-450 enzyme system, and famotidine has essentially no effect - significant interactions more likely to arise with medications having a narrow therapeutic range, such as theophylline, warfarin, lidocaine, and phenytoin - All 4 drugs may inhibit absorption of certain drugs, such as ketoconazole, that require an acidic GI environment for gastric absorption - smoking decreases effectiveness of H2 antagonists - they are taken 1-2 hours BEFORE antacids

Question 33

H2 Receptor Antagonist: Cimetidine (Tagamet)

Answer 33

- Because of potential to cause drug interactions, its use has been replaced by ranitidine and famotidine - still used to treat certain allergic reactions

Question 34

H2 Receptor Antagonist: Ranitidine (Zantac)

Answer 34

- does not carry concerns over drug interactions that cimetidine has and has become most widely used - oral and IV - dosing different for different forms - oral ranitidine is dosed as 150mg twice a day or 300 mg at bedtime - IV dosed at 50 mg every 8 hours

Question 35

H2 Receptor Antagonist: Famotidine (Pepcid)

Answer 35

- Has no drug interaction concerns - oral and injectable froms - dosing same for both forms

Question 36

The newest drugs introduced for the treatment of acid-related disorders are the PPIs. These include?

Answer 36

lansoprazole (Prevacid) pantoprazole (Protonix) esomeprazole (Nexium)

Question 37

The PPIs bind directly to the?

Answer 37

hydrogen–potassium–ATPase pump mechanism and irreversibly inhibit the action of this enzyme, resulting in total blockage of hydrogen ion secretion. PPIs block the final step in the acid production pathway, the hydrogen–potassium–ATPase pump and they block all acid secretion.

Question 38

Proton Pump inhibitors bind irreversibly to the proton pum. This inhibition prevents the movement of?

Answer 38

Hydrogen ions out of the parietal cell into the stomach and thereby blocks all gastric acid secretion. -PPIs stop more than 90% of acid secretion over 24 hrs, which makes most pt's temporarily achlorhydric (without acid) Achlorhydrai complications: bacterial overgrowth, intestinal metaplasia, hip fracture (food absorption NOT affected)

Question 39

For acid secretion to return to normal after a PPI has been stopped what happens?

Answer 39

The parietal cell must synthesize new hydrogen-potassium-ATPase

Question 40

The action of PPIs is limited to its effects on?

Answer 40

Gastric acid secretion

Question 41

Proton pump inhibitors indications

Answer 41

PPIs are currently indicated as first-line therapy for erosive esophagitis, symptomatic GERD that is poorly responsive to other medical treatment such as therapy with H2 receptor antagonists, short-term treatment of active duodenal ulcers and active benign gastric ulcers, gastric hypersecretory conditions (e.g., Zollinger-Ellison syndrome), nonsteroidal anti-inflammatory drug (NSAID)–induced ulcers, and for stress ulcer prophylaxis.

Question 42

long term therapeutic uses of PPIs include?

Answer 42

Maintenance of healing of erosive esophagitis and pathologic hypersecretory conditions, including GERD and Zollinger-Ellison syndrome

Question 43

All PPI can be used in combination with?

Answer 43

Antibiotics to treat pt's with H.pylori infections

Question 44

PPIs can be given?

Answer 44

Orally or through an NG or percutaneous enterogastric tube

Question 45

PPI: Pantoprazole granules are to be used with NG tubes that are?

Answer 45

Larger than 16 French because it may clog smaller tubes

Question 46

PPIs Adverse effects

Answer 46

-well tolerated -may predispose to GI tract infections -potential long term use associated with osteoporsis - The U.S. Food and Drug Administration issued a warning in 2010 regarding long-term use of high-dose PPIs, which has been associated with Clostridium difficile infections; risk of wrist, hip, and spine fractures; and pneumonia. In 2011, depletion of magnesium was added to the warning.

Question 47

PPIs interactions

Answer 47

- PPIs may increase serum levels of diazepam and phenytoin and there may be an increased chance of bleeding in patients who are taking both a PPI and warfarin. - interference w/absorption of ketoconazole, ampicillin, iron salts, and digoxin - when given w/clopidogrel increased risk for death if have acute coronary syndrome - Sucralfate may delay absorption of PPIs - DON'T take w/food

Question 48

PPI: Lansoprazole (Prevacid)

Answer 48

- delay release capsule, granule for oral suspension, & orally disintegrating tablets - capsules can be opened and mixed (NOT crushed) with apple juice for administration via NG tube, or the SoluTab can be dissolved in water - also available as combination products for Tx of H. Pylori infection

Question 49

PPI: Pantoprazole (Protonix)

Answer 49

- first PPI for IV use - first to be used as a continuous infusion for Tx of GI bleeding - oral tablet and as delayed-release granules for NG administration - granules are large, and the NG tube must be at least size 16 French, or the granule may clog tube

Question 50

Miscellaneous Acid-Controlling Drugs: Simethicone (Mylicon)

Answer 50

- used to reduce discomforts of gastric or intestinal gas (flatulence) and aid in its release via the mouth or rectum - antiflatulent - works by altering the elasticity of mucus-coated gas bubbles, which causes them to break into smaller ones. This reduces gas pain and facilitates the expulsion of gas via the mouth or rectum - ORAL - dosage is 1-2 tabs four to six times daily

Question 51

Before an acid-controlling drug is given, perform a thorough patient assessment with attention to past and present medical history and with special focus on?

Answer 51

GI tract–related disorders and signs and symptoms of ulcer disease and GERD. - assess current bowel patterns, any change in bowel patterns or GI tract functioning, and GI tract related pain - pay attention to hepatic function (serum ALP, ALT, AST levels) and renal function (serum creatinine and BUN levels) - take cardiac history with close attention to history of heart failure, HTN, other cardiac diseases, the presence of edema, fluid and electrolyte imbalances, and renal disease. This is important because high sodium content of various antacids, if used, could lead to exacerbation of cardiac problems, renal dysfunction, and fluid-electrolyte problems

Question 52

Since acid-controlling drugs have many interactions, underscore the importance of obtaining a?

Answer 52

medication history about prescription drugs, over-the-counter drugs, and herbals.

Question 53

When antacids containing aluminum and/or magnesium are used, identify all other medications the patient is taking. It is important to note that combination products containing both magnesium and aluminum may have?

Answer 53

Fewer AEs than either type of antacid by itself

Question 54

Magnesium-containing antacids may lead to?

Answer 54

Diarrhea

Question 55

Calcium-based antacids may also be used, especially as a source of calcium; however, they carry the risk for?

Answer 55

Rebound hyperacidity, milk-alkali syndrome, and changes in systemic pH, especially if pt has abnormal renal functioning

Question 56

For patients using H2 receptor antagonist drugs, assess?

Answer 56

renal and liver function and level of consciousness. Elderly patients react to these drugs with more disorientation and confusion.

Question 57

Do not administer drugs such as cimetidine and famotidine simultaneously with?

Answer 57

antacids | -these drugs may be spaced 1 hour apart if both drugs need to be given

Question 58

In patients taking Ranitidine (H2 receptor antagonist) assess?

Answer 58

Baseline blood chemistry results, with attention to levels of BUN, creatinine, bilirubin, ALP, AST, and ALT to document renal and hepatic functioning BEFORE Tx is initiated

Question 59

For PPIs (Lansoprazole, Esomeprazole, Pantoprazole), assess?

Answer 59

Swallowing capacity because of the size of some of the oral capsules - medical history w/emphasis on GI tract infection due to decreased acid-mediated antimicrobial protection - Since there are documented concerns about the use of PPIs and development of osteoporosis, thoroughly assess patientsnfor any history of this disorder or manifestations

Question 60

PPI (Lansoprazole, Esomeprazole, Pantoprazole) Interactions

Answer 60

Diazepam, phenytoin, warfarin, ampicillin, iron salts

Question 61

Miscellaneous acid-controlling drugs: The use of simethicone and sucralfate requires assessment of the patient’s?

Answer 61

bowel patterns and bowel sounds and evaluation | for abdominal distention and rigidity (medical emergency)

Question 62

Treatment of peptic ulcer disease has become focused on the use of antibiotics (to attack the H. Pylori bacteria) with frequent dosing of other drugs. Inquire about the presence of any unusual s/s related to the?

Answer 62

GI tract

Question 63

When giving acid-controlling drugs, instruct the patient to?

Answer 63

1) thoroughly chew the chewable tablets 2) thoroughly shake liquid forms 3) Antacids need to be given with at least 8 ounces of water to enhance absorption, except for newer forms that are rapidly dissolving drugs

Question 64

If constipation or diarrhea occurs with single-component drugs, a combination?

Answer 64

Aluminum and magnesium-based antacid may be preferred | -educate about AEs of aluminum only or magnesium only products

Question 65

It is recommended that antacids be given as ordered, but not?

Answer 65

Within 1-2 hours of other medications because antacids may impair absorption of other oral medications

Question 66

With quinolone antibiotics, there may be serious harm if | given with?

Answer 66

antacids because of a 50% reduction in antibiotic absorption. -serious infections may then go unsuccessfully treated due to altered absorption

Question 67

Antacid overuse/misuse or the rapid discontinuation of antacids with high acid-neutralizing capacity may lead to ?

Answer 67

Acid rebound

Question 68

H2 receptor antagonist: cimetidine is to be taken?

Answer 68

With meals, and antacids, if also used, need to be taken 1-2 hours after the cimetidine

Question 69

H2 Receptor antagonist: Famotidine may be given?

Answer 69

Orally in tablet or suspension and without regard to meals or food -rapid release forms dissolve quickly under tongue and can be taken w/out water

Question 70

Give Ranitidine (H2 receptor antagonist) as ordered, and, if administered with antacids, give?

Answer 70

The antacids 1 hour BEFORE or 1 hour AFTER ranitidine

Question 71

Dilute IV forms of famotidine or ranitidne with?

Answer 71

Appropriate solutions, and infuse over the documented time frame

Question 72

With IV H2 receptor antagonists, what may occur?

Answer 72

Hypotension may occur with rapid infusion, so careful monitoring is critical

Question 73

For all of these H2 receptor antagonists, monitor?

Answer 73

blood pressure readings as needed during intravenous infusion because of the risk of hypotension. Continue to monitor the patient for GI tract bleeding with the diagnosis of ulcers or GI irritation. -Report any blood in the stools or the occurrence of black, tarry stools or hematemesis -listen to bowel sounds, and examine the abdomen to monitor for possible complications

Question 74

With PPIs, give lansoprazole oral dosage forms as ordered. If patient has difficulty swallowing these capsules what can you do?

Answer 74

A capsule may be opened and the granules sprinkled over at least a table spoon of applesauce, which then must be swallowed immediately

Question 75

PPI: Pantoprazole (Protonix) may be given?

Answer 75

Orally without crushing or splitting of the tablet form | -give IV forms exactly as ordered using correct dilutional fluids & infuse over recommended time

Question 76

Simethicone (Mylicon) may also be added to the oral medication protocol with PPIs. It is usually well tolerated. It is taken?

Answer 76

After meals and at bedtime | -chew tablets or shake suspensions well before use

Question 77

Antacids are to be avoided for?

Answer 77

30 minutes before or after administration of sucralfate

Question 78

Contact prescriber if there is severe or prolonged?

Answer 78

Constipation and/or diarrhea; increase in abdominal pain; abdominal distention; nausea; vomiting; hematemesis; black tarry stools (sign of possible GI tract bleeding)

Question 79

If patient is taking enteric-coated medications, educate about the fact that the use of antacids may?

Answer 79

Promote premature dissolution of the enteric coating -enteric coatings used to diminish the stomach upset caused by irritating medications, if coating is destroyed early in the stomach, gastric upset may occur

Question 80

Antacids should not be used for prolonged periods without medical attention. A health care provider should be contacted after?

Answer 80

2 weeks

Question 81

Encourage the patient to take H2 Receptor antagonists exactly as prescribed. Inform the patient that smoking?

Answer 81

Decreases the drugs effectiveness | -Advise the pt taking cimetidine and antacids that the antacid is to be taken either 1 hour before or after cimetidine

Question 82

What may occur with cimetidien (h2 receptor antagonist)

Answer 82

Gynecomastia and impotence may occur and are reversible | -report bruising, fatigue, diarrhea, black tarry stools, sore throat, or rash

Question 83

Ranitidine (h2 receptor antagonist) is not to be taken for?

Answer 83

More than 2 weeks. Once daily dosing is recommended before bedtime

Question 84

Omeprazole and other PPIs are to be taken?

Answer 84

Before meals. Inform pt if lansoprazole is being used, the granules may be sprinkled from the capsule into a tablespoon of applesauce

Question 85

For pt's with GERD or hyperacidity, educate about the avoidance of?

Answer 85

Black pepper, caffeine, alcohol, harsh spices, and extremes in food temp

Question 86

Instruct patient to follow directions when taking simethicone (misc acid-controlling drug). Chewable forms must always be?

Answer 86

Chewed thoroughly; liquid preparations need to be shaken thoroughly before administration -encourage pt's experiencing flatulence to avoid problematic foods (spicy, gas-producing foods) and carbonated beverages

Question 87

For a pt taking the drug regimen for the tx of H. pylori infection-peptic ulcer disease, it is important to emphasize the need to take each drug, including the antibiotic, exactly as prescribed and without fail to guarantee

Answer 87

Successful tx