Drugs Affecting the Gastrointestinal System and Nutrition.ppt by shenreng9qgrg132


									Drugs Affecting the
Gastrointestinal System and
    Jan Bazner-Chandler MSN, CNS, RN,
Acid-related Pathophysiology

   Hydrochloric acid (HCL) aids in digestion and
    serves as a barrier to infection.
   Pepsinogen is an enzyme that digests dietary
   Mucous protects the lining of the stomach
    from both HCL and digestive enzymes.
   Prostaglandins has an anti-inflammatory and
    protective function.

   Are basic compounds used to neutralize
    stomach acid.
OTC Products

   Antacids were the most common products
    used for acid-indigestion until the 1970’s
    when histamine-2 (H2 antagonists) were

   Primary drug effect of antacids is the
    reduction of symptoms associated with acid-
    related disorders: pain and reflux (heartburn)
   Raises gastric pH from 1.3 to 1.6.

   Acute relief of symptoms associated with:
       peptic ulcer disease (PUD)
       Gastritis
       gastric hyperacidity
       Heartburn or gastro esophageal reflux (GEF)

   Most common disorder of esophagus
   Characterized by regurgitation of gastric
    contents into esophagus and exposure of
    esophageal mucous to gastric acid and
   Main symptom is heart burn - occurs after
   Cause is thought to be incompetent lower
    esophageal sphincter
Peptic Ulcer Disease

   Ulcer formation in the esophagus, stomach or
   Mucous exposed to gastric acid and pepsin
   Imbalance between cell-destructive and cell-
    protective effects
       Gastric acid and pepsin
       H. pylori – infectious process
Peptic Ulcer Disease
Adverse Effects

   Magnesium preparations especially milk of
    magnesium or MOM can cause diarrhea.
   Calcium products can cause kidney stones.
   Sodium bicarbonate products can cause
    systemic alkalosis.
   Self-treatment can result in masking
    symptoms of a disease (bleeding ulcer or
    stomach cancer).
Keep away from small children

   Alkalosis

   Allergy to the drug
   Severe renal failure
   Electrolyte disturbances
   Gastro intestinal obstruction

   May effect absorption of other drugs.
   Chemically inactivates certain drugs
   Increased stomach pH decreasing absorption
    of acidic drugs
OTC Preparations

   Magnesium-containing antacids
       Gaviscon Liquid, Milk of Magnesium
   Aluminum-containing antacids
       Amphogel, Maalox
   Sodium-containing antacids
       Alka-seltzer, Tums
Gelusil / Mylanta

   Chewable forms needs to be thoroughly
   Liquid forms need to be shaken well before
   Take with 8 ounces of water to enhance
   Do not take within 1 to 2 hours of taking other
    medications – may effect absorption
H 2 Antagonists

   H2 receptor blockers
       cimetadine (Tagamet),
       ranitidine (Zantac)
       famotidine (Pepcid)
       nizatidine (Axid)
H2 antagonist HAs

   Action:
       blocks the H2 receptor of acid-producing parietal
       Reduce hydrogen ion secretions to increase pH of
Therapeutic Uses

   GERD or gastro-esophageal reflux
   PUD or peptic ulcer disease
   Zollinger-Ellison Syndrome (excessive gastric
Adverse Effects

   Overall very low incidence of adverse effects
   May cause some CNS effects in the geriatric
   Smoking reduces effectiveness
   H2 antagonist should be taken 1 hours before
    taking any antacids
Proton Pump Inhibitors

   Newest drugs used in the treatment of acid-
    related disorders.
       lansopraxole (Prevacid)
       omeprazole (Prilosec)
       rabeprzole (Acephex)
       pantoprazole (Protonix)
       exomepraxole (Nexium)

   Action: Binds directly to the hydrogen-
    potassium - ATPase pump mechanism,
    inhibiting the action of the enzyme which
    results in a total blockage of hydrogen ion
    secretion from the parietal cells.
Adverse Effects

   Long term use might promote malignant
    gastric tumors.
   Concern about over prescribing resulting in
    reduction of normal acid-mediated
    antimicrobial protection.
   May need a probiotic when using PPI drug
Miscellaneous Acid-Controlling Drugs

   sucralfate (Carafate)
   Uses: long-term therapy for PUD
   Action: acts locally binding directly to the
    surface of the ulcer.
   Note: not used as often due to short-term
    action and multiple daily dosing.

   Generic: misoprostol
   Action: acts on prostaglandin E analogue
   Indication: reduces the incidence of gastric
    ulcers in patients taking NSAIDs.

   Generic: simethicone
   Action: alters the elasticity of mucus-coated
    gas bubbles, causing them to break down
    into smaller ones

   Used to reduce the discomfort of gastric or
    intestinal gas (flatulence)
   Used post-operatively and in post-partum
    patients to relieve gas pain.
   Often used in combination with activated
    charcoal in oral poisoning (overdose).

   Probiotics are live microorganisms (in most
    cases, bacteria) that are similar to beneficial
    microorganisms found in the human gut.
    They are also called "friendly bacteria" or
    "good bacteria." Probiotics are available to
    consumers mainly in the form of dietary
    supplements and foods. They can be used as
    complementary and alternative medicine.

   Probiotics are available in foods and dietary
    supplements. Examples of foods containing
    probiotics are yogurt, fermented and
    unfermented milk, miso, and some juices and
    soy beverages. In probiotic foods and
    supplements, the bacteria may have been
    present originally or added during

   Most probiotics are bacteria similar to those
    naturally found in people's guts, especially in
    those of breastfed infants (who have natural
    protection against many diseases). Most
    often, the bacteria come from two groups,
    Lactobacillus or Bifidobacterium. A few
    common probiotics, such as Saccharomyces
    boulardii, are yeasts, which are different from

   Chronic Diarrhea
   Irritable Bowel Syndrome
   Digestive disorders
   Clients on oral or IV antibiotic therapy
   Status post abdominal surgery
Antidiarrheals and Laxatives

    Chapter 42
Antidiarrheal Drugs

   Used to treat diarrhea.
       Adsorbents
       Antimotility (anticholenergic and opiates)
       Intestinal flora modifiers or bacterial replacement

   Act by coating the walls of the GI tract.
   Bind with the causative bacteria or toxin to
    their adsorbent surface for elimination
    through the stool.
Pepto-Bismul and Kaoectate

   Generic: bismuth subsalicylate
   Same chemical structure as salicylate
        use with caution in children. May cause Reyes
       Use with caution in clients who are on anti-
        coagulation therapy.
FDA Warning

   The main ingredient, bismuth subsalicylate,
    has been linked with Reye Syndrome, a
    potentially life-threatening disorder that has
    been associated with kids that have viral
    illnesses, especially the flu and chicken pox,
    and who take aspirin and other salicylate
    containing medications, like Pepto-Bismol.
   Label advises not to give to children under
    age 12 years.

   Used either alone or in combination with
    other antidiarrheal drugs.
   Acts by slowing GI tract motility
       Atropine
       hyoscyamine
       hyoscine

   Products containing Codeine
   Nursing consideration: clients on opioids for
    post-operative pain control may suffer from
   Atropine: often used to control secretions
    during surgical procedure – may contribute to
    post-operative constipation
Imodium A D

   Generic name: loperamide
   Classification: Opiate antidiarrheal
   Action: inhibits both peristalsis in the intestine
    and intestinal secretions, decreasing the
    number of stools and their water content.
   Contraindications: ulcerative colitis, acute
    diarrhea due to E-coli (Escherichia coli)

   Laxative act by:
       Affecting the consistency of the stool
       Increasing fecal movement through the colon
       Facilitating movement through the colon

   Definition: abnormally infrequent and difficult
    passage of feces.
   Constipation is a symptom not a disease.
Bulk-forming Laxatives

   Composed of water-retaining natural and
    synthetic cellulose derivates.
       Psylium is an example of natural bulk-forming
       Methylcellulose is an example of a synthetic
        cellulose derivative.
Bulk-forming Laxative

   Action: increases water absorption, which
    results in greater bulk of the intestinal
   Tend to produce normal, formed stools.
   Action limited to GI tract so adverse effects
    are minimal.
Citrucel (methylcellulose)
Nursing Alert

   Have client take with 8 ounces of water.
   If powdered form needs to be mixed with 8
    ounces of water.
   Fluid must be taken immediately to avoid
    swelling of the product in the throat or
    esophagus or fecal impaction.
   Best for clients with chronic constipation.
Emollient laxative

   Generic classification: docusate salts
   Trade names: Colace, Surfak
   Action: work by lowering the surface tension
    of GI fluids; more water and fat are absorbed
    into the stool and intestine.

   Uses:
       post partum
       postoperative patients
       Clients on long-term pain control
   Outcomes: soft stool with easier defecation
Mineral Oil

   Action: eases the passage of stool by
    lubricating the intestines and preventing
    water from escaping the stool.
   Contraindications
       Abdominal pain
       Nausea and vomiting
       Intestinal obstruction
Hyperosmotic Laxatives

   Glycerine
   Action: promotes bowel movement by
    increasing the osmotic pressure in the
   Note: given in the form of a suppository
Stimulant Laxatives

   Through the use of natural plant products and
    synthetic chemical drugs induces intestinal
   Note: the stimulant class is the most likely to
    cause dependence.
Stimulant Laxatives

   Generic: senna
   Trade: Senokot
   Action: stimulates the GI tract
   Adverse effects: may cause abdominal pain.
   Onset of action: complete bowel evacuation
    in 6 to 12 hours.
Irritable Bowel Syndrome IBS

   A condition of chronic intestinal discomfort,
    including cramps, diarrhea / or constipation.
   Two drugs to manage symptoms:
       Lotronex (alostron) – approved for women only
       Zelnorm (tegaserod) – approved for men and
           Action: works on serotonin receptors in the intestinal
Antiemetic and Antinausea

    Chapter 52
Chemoreceptor Trigger Zone (CTZ)

   The area of the brain that is involved in the
    sensation of nausea and the action of
Vomiting Center (VT)

   The area of the brain that is involved in
    stimulating the physiologic events that lead to
    nausea and vomiting.
Antiemetic Drugs

   Drugs used to relieve nausea and vomiting.
   All emetic drugs work at some site in the
    vomiting pathways.
Syrup of Ipecac

   AAP recommendations in 2003 issued an
    alert to stop the use of this drug to induce
    vomiting after drug overdose.
Anticholinergic Drugs

   Act by binding to and blocking acetylcholine
    receptors (ACh) in the vestibular nuclei,
    located deep in the brain.
   One drug scopolamine
   Most commonly used drug for treatment and
    prevention of nausea and vomiting
    associated with motion sickness and

   Action: binds to H1 receptors, potentiate
    anticholinergic activity.
   Most popular OTC medications
   Generic name: dimenhydrinate
   Trade name: Dramamine and Benadryl
   OTC drugs used for motion sickness

   Action: antidopaminergic, antihistamine and
    anticholinergic properties.
   Trade names: Compazine, Thorazine,
   Often given as preoperative medication.
   Used to treat psychotic disorders due to
    effect on dopamine.
Compazine: Nursing Alert

   Adverse reaction: extrapyramidal reaction--a
    muscle spasm of the tongue. Other typical
    adverse extrapyramidal reactions include
    tremors, drooling, and muscle spasms that
    usually involve muscles in the shoulders,
    neck, or eyes.
   Antidote: Benadryl

   Metoclopramide
   Trade name: Reglan
   Action: promote the movement of substances
    through the GI tract and increases motility.
   Often given in patients getting tube feeding to
    promote gastric emptying time.
Serotonin Blockers

   Called 5-HT3 receptor blockers because they
    block the 5-HT3 receptors in the GI tract,
    CTZ and vomiting centers VC.
   Four drugs in this category

    Trade name: Zofran is the prototype drug.
        Approved in 1992.
        Major break through in treating chemotherapy induced
         nausea and vomiting and postoperative nausea and
        Approved for use in pregnancy.
Side effects from all antiemetics

   May cause dizziness
   Caution with use while driving.
   CNS depression
   Hypotension
Herbal Therapies

   Ginger Root
   May increase absorption of all oral
    mediations, may increase bleeding in clients
    taking Coumadin and Plavix.

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