Pharmacology, Intravenous Therapy & Nutrition Flashcards
What are antacids
Antacids commonly prescribed have at least one of the following elements as their main ingredient:
1. Aluminum salts
2. Calcium carbonate
3. Magnesium salts
The ingredient alginate is not an antacid but may provide barrier protections
Are available OTC
What is the mechanism of action of antacids
- Antacids have no direct effect on gastric acid secretin and do not coat or protect the mucous lining.
- Instead, antacids neutralize gastric acid, reducing the total acid load in the GI tract and leading to a transient rise of gastric pH.
- This decreases pepsin activity because pepsin is rendered inactive in alkaline conditions.
- It also increases LES tone, reducing reflux
- Aluminum ions inhibit smooth muscle contraction and gastric emptying. This action is counterproductive because in gastroesophageal reflux disease (GERD), prompt gastric emptying is beneficial
What are the indications for antacids
Antacids are indicated in the treatment of:
1. Hyperacidity—heartburn (pyrosis)
2. Gastroesophageal reflux disease (GERD)
3. Acid indigestion
4. Hyperacidity associated with peptic ulcer disease
- Research studies demonstrate that antacids are clearly superior to placebos in healing gastric ulcers
Because antacids leave the stomach rapidly, they are best used for intermittent symptoms.
Taken on an empty stomach, the effects of antacids last less than 1 hour.
After meals, the buffering effect may last as long as 3 hours
For optimal effect, antacids should be given about 1 hour after meals or feedings and during periods of acid rebound
What are adverse effects of antacids
- Prolonged use of magnesium or calcium containing antacids may cause systemic absorption of toxic quantities of these ions.
- Excessive use of aluminum containing antacids my lead to hypophosphatemia
- Aluminum and calcium preparations tend to be constipating, whereas magnesium preparations tend to produce a laxative effect
- In chronic patients with renal failure, administration of aluminum-containing antacids is best at mealtime
- Antacids containing sodium can precipitate edema in patients with cirrhosis, hypertension, or renal or congestive heart failure
What are contraindications of use of antacids
- In patients taking tetracycline, iron, or H2-receptor antagonists
—Calcium binds and prevents absorption of tetracycline, whereas antacids decrease the absorption of iron and H2blockers - Magnesium containing antacids can precipitate hypermagnesemia in patients with chronic renal failure and should be avoided in these patients, as central nervous system depression, skin irritation, and rarely, muscle paralysis with respiratory failure can occur
What are examples of antacids
- Aluminum hydroxide gel
- Calcium carbonate (Alkaline-Seltzer, Tums)
- Magnesium hydroxide (Milk of Magnesia)
- Gaviscon, Gelusil, Maalox, Mylanta, Rolaids
- Pepto-Bismol
What are antibiotics
- May be prescribed for pediatric and adult patients
- The nurse needs to have a basic knowledge of mechanism of action, antimicrobial spectrum, typical uses, and toxicity of commonly used antibiotics
- Cost and dosing schedules must be considered in the decision-making process when prescribing, in order to enhance patient compliance
- Knowledge of patient drug allergies, recommended dosages, and bacterial taxonomy is of critical importance for GI nurses in order to provide safe medical care and promote patient and family education
What is the mechanism of action for antibiotics
- Antibiotics are antimicrobial agents
- The specific antibiotic drug selection depends on the pathogen, drug adverse-effect profile, patient drug allergies, age of the patient, and any comorbid illness
What are the indications for antibiotics
For infectious agents found in the GI tract
- Mouth infections
- Gastroenteritis
- Traveler’s diarrhea
- Severe diarrhea
- Diverticulitis
- Gastritis and ulcers
What are indications of using antibiotics for prophylaxis
- Prosthetic cardiac valves, including trans catheter implanted prostheses and homografts
- Prosthetic material used for cardiac valve repair such as annuloplasty rings and chords
- previous IE (infectious endocarditis)
- Unrepaired cyanotic congenital heart disease or repaired congenital heart disease with residual shunts or valvular regurgitation at the site of or adjacent to the site of a prosthetic patch or prosthetic device
- Cardiac transplant with valve regurgitation due to a structurally abnormal valve
What are adverse effects of antibiotics
- Side effects may vary depending on agent given and can include nausea, vomiting, diarrhea, rash, urticaria, headache, and anaphylaxis
- The administering provider should be familiar with the medication, its potential side effects and their contraindications prior to drug administration
What are contraindications of antibiotics
Contraindications include a known sensitivity to the antibiotic agent
What are examples of antibiotics
- Clindamycin
- Ampicillin
- Tetracycline
- Ciprofloxacin
- Levofloxacin
- Moxifloxacin hydrochloride
- Metronidazole
- Azithromycin
- Clarithromycin
- Trimethoprim-sulfamethoxazole (TMP-SMX)
- Vancomycin
What are Anticholinergic
Substances that block the action of the neurotransmitter called acetycholine at synapses in the central and peripheral nervous system
What is the mechanism of action for Anticholinergic drugs
- Inhibit gastric acid secretions at its source by blocking the acetylcholine receptor on gastric parietal cells
- Decrease the output of pepsin and block vagal stimulation of the smooth muscle, thus decreasing GI tone and motility
- They also decrease gastric emptying tome, presumably through their inhibition of vagal and cholinergic-mediated motility
What are indications for Anticholinergic medications
In treatment for:
- Diffuse esophageal spasm
- Peptic ulcer disease
- IBS
- Diverticulitis
- Hypermotility disorders
- Ulcerative colitis
Can be use to relived the gastric distress caused by gastric spasms, hyperperistalsis, and rapid emptying of the stomach
Because of their side effects they are primarily used as an adjunctive therapy for peptic ulcer disease in combination with antacids or H2 blockers
Best given approximately 1 hour after meals, when food-stimulated acid is at its peak
Their effects persist for 4-5hours
What are adverse effects of Anticholinergics
- Dry mouth, nose and throat
- Hoarseness
- Tachycardia
- Blurred vision
- Urinary hesitancy or retention
- Flushing of the skin
- Constipation
What are contraindications of anticholinergics
In patients who experience bleeding or who have tachycardia, closed angle glaucoma, Achalasia, obstruction, or suspected toxic mega colon
What are examples of Anticholinergic drugs
- Atropine sulfate
- Hyoscyamine
- Dicyclomine hydrochloride (Bentyl)
- Lomotil
What are cholinergic drugs
Mimic the action of acetycholine and/or butrylcholine
What is the mechanism of action for cholinergic drugs
- In contrast to Anticholinergic agents, they increase GI tone and motility
- Produce the same effects as stimulation of the parasympathetic nervous system, thereby stimulating GI secretion and motility
What are indications for the use of cholinergic drugs
- Bethanechol may be used to increase LES pressure in patients suffering from GERD
- also used in children with GERD who are unresponsive to metoclopramide (reglan)
- Domperidone is a peripheral dopamine antagonist that has a safety profile similar to reglan, used to enhance gastric emptying. - not FDA approved in the US
- Cisapride used to relieve symptoms of reflux esophagitis by increasing contractions in the stomach to improve stomach emptying - removed from the market in late 2000
What are adverse effects of cholinergic medications
Cause the same parasympathetic symptoms as anticholinergics, which may include diaphoresis and bladder contractions
What are contraindications of cholinergic medications
Peptic ulcers or possible GI obstruction