Gastrointestinal Agents

Drugs Used to Treat Gastrointestinal Diseases

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Histamine2-Receptor Antagonists cimetidine (Tagamet) nizatidine (Axid) “tidine” • H2 antagonist- block the action of histamine on parietal cells in the stomach = decrease acid production • Indications: Peptic Ulcer Diseas (PUD), gastroesophageal reflux disease (GERD) • Use decreased r/t Proton Pump Inhibitors (PPIs) use (PPIs more effective) Elsevier Inc. items and derived items © 2007 by Saunders, an imprint of Elsevier Inc.

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• Reduces metabolism of drugs r/t decreased acid production • Increases serum concentrations i.e. – warfarin (Coumadin) – phenytoin (Dilantin) – Cardiac medications i.e. Calcium Channel blockers; Beta blockers

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Proton Pump Inhibitors omeprazole (Prilosec) pantoprazole( Protonix)

“azole” • Used for long-lasting reduction of gastric acid production • Most potent / most effective – Short half-life / short-term therapy • Given PO or IV • Adverse effects Most common H/A; Nausea; Diarrhea Elsevier Inc. items and derived items © 2007 by Saunders, an imprint of Elsevier Inc.

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sucralfate (Carafate) • Locally acting in an acidic environment (pH < 4), reacts with HCL to form a acid buffer • Protective barrier up to 6 hours to 8 hours after a single dose • Uses – Acute ulcers – preferred agent for stress ulcer prophylaxis • Adverse effects – Constipation Elsevier Inc. items and derived items © 2007 by Saunders, an imprint of Elsevier Inc.

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Nursing Implications • Assess reports of GI complaints • Administration guidelines – H2RAs: oral: take with or w/o meals IV: must be diluted with 0.9% saline – PPIs:

oral: take one hr before meals IV: must be diluted with 0.9% saline and use an “in-line filter”

• Monitor therapeutic effects

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Antiemetics Drugs used to prevent or treat N/V induced by drugs, radiation, surgery, and most other stimuli

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Benzodiazepine Antianxiety Drugs • Used in multidrug regimens to prevent N/V r/t cancer chemotherapy • Relax and inhibit cerebral input to vomiting center • Lorazepam (Ativan) commonly used Elsevier Inc. items and derived items © 2007 by Saunders, an imprint of Elsevier Inc.

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5-Hydroxytryptamine3 Receptor Antagonists • Ondansetron (Zofran), granisetron (Kytril), and dolasetron (Anzemet) • Used to prevent or treat moderate to severe N/V r/t cancer chemotherapy, radiation, and postoperatively • Antagonize receptors and prevent activation by emetogenic anticancer drugs Elsevier Inc. items and derived items © 2007 by Saunders, an imprint of Elsevier Inc.

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Miscellaneous Antiemetics • metoclopramide (Reglan) – Agent that increases GI motility and rate of gastric emptying

• phosphorated carbohydrate solution (Emetrol) – Reduces smooth muscle contraction in GI tract (OTC)

• Scopolamine is an anticholinergic drug – Active in relieving motion sickness; – available as transdermal patch

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