Ppt chapter 57

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Drugs Affecting Gastrointestinal Secretions

Drugs Affecting Gastrointestinal Secretions

Chapter 57


Underlying Causes of GI DisordersUnderlying Causes of GI Disorders• Dietary Excess

• Stress

• Hiatal Hernia

• Esophageal Reflux

• Adverse Drug Effects

• Peptic Ulcer Disease


Effect of Drugs on GI SecretionsEffect of Drugs on GI Secretions• Decrease GI secretory activity

• Block the action of GI secretions

• Form protective coverings on the GI lining to prevent erosion from GI secretions

• Replace missing GI enzymes that the GI tract or ancillary glands and organs can no longer produce


Peptic Ulcer DiseasePeptic Ulcer Disease• Definition

– Erosions in the lining of the stomach and adjacent areas of the GI tract

• Symptoms

– Gnawing, burning pain, often occurring after meals

• Cause

– Bacterial infection by Helicobacter pylori bacteria


Drugs Used in the Treatment of UlcersDrugs Used in the Treatment of Ulcers

• Histamine-2 (H2) Antagonists

– Block the release of hydrochloric acid in response to gastrin

• Antacids

– Interact with acids at the chemical level to neutralize them

• Proton Pump Inhibitors

– Suppress the secretion of hydrochloric acid into the lumen of the stomach


Drugs Used in the Treatment of Ulcers (cont.)

Drugs Used in the Treatment of Ulcers (cont.)

• Antipeptic Agents

– Coat any injured area in the stomach to prevent further injury from acid

• Prostaglandins

– Inhibit the secretion of gastrin and increase the secretion of the mucous lining of the stomach, providing a buffer


Sites of Actions of Drugs Affecting Gastrointestinal Secretions

Sites of Actions of Drugs Affecting Gastrointestinal Secretions


Histamine-2 (H2) AntagonistsHistamine-2 (H2) Antagonists

• Actions

– Selectively block histamine-2 receptor sites

– This blocking leads to a reduction in gastric acid secretion and reduction in overall pepsin production

• Indications

– Short-term treatment of active duodenal ulcer or benign gastric ulcer

– Treatment of pathological hypersecretory conditions such as Zollinger–Ellison syndrome

– Prophylaxis of stress-induced ulcers and acute upper GI bleeding in critical patients


Histamine-2 (H2) Antagonists (cont.)Histamine-2 (H2) Antagonists (cont.)

• Indications (cont.)

– Treatment of erosive gastroesophageal reflux

– Relief of symptoms of heartburn, acid indigestion, and sour stomach (OTC preparations)

• Pharmacokinetics

– Readily absorbed after oral administration

– Metabolized in the liver and excreted in urine

• Contraindications

– Known allergy


Histamine-2 (H2) Antagonists (cont.)Histamine-2 (H2) Antagonists (cont.)• Caution

– Pregnancy or lactation

– Hepatic or renal dysfunction

• Adverse Effects

– GI effects

– CNS effects

– Cardiac arrhythmias and hypotension

• Drug-to-Drug Interactions

– Warfarin, phenytoin, beta blockers, alcohol, quinidine, lidocaine, theophylline, chloroquine, benzodiazepines, nifedipine, pentoxifylline, tricyclics, procainamide, and carbamazepine


QuestionQuestion

Drugs act in several ways on the secretions of the GI tract. Which action affects the GI secretions least?

A. Decreases secretory activity

B. Blocks secretions

C. Replaces secretions

D. Prevents erosions


AnswerAnswer

C. Replaces secretions

Rationale: The effects of drugs on GI secretions: decrease GI secretory activity; block the action of GI secretions; form protective coverings on the GI lining to prevent erosion from GI secretions; replace missing GI enzymes that the GI tract or ancillary glands and organs can no longer produce


AntacidsAntacids• Actions

– Neutralize stomach acid by direct chemical reaction

• Indications

– Symptomatic relief of upset stomach associated with hyperacidity, as well as hyperactivity


– Allergy

• Caution

– Any condition that can be exacerbated by electrolyte imbalance

– GI obstruction


Antacids (cont.)Antacids (cont.)• Adverse Effects

– Relate to their effects on acid-base levels and electrolytes

– Rebound acidity

– Alkalosis

– Hypercalcemia

– Constipation or diarrhea

– Hypophosphatemia


– Affect the absorption of many other drugs


Proton Pump InhibitorsProton Pump Inhibitors• Actions

– Act at specific secretory surface receptors to prevent the final step of acid production and thereby decrease the level of acid in the stomach

• Indications

– Short-term treatment of active duodenal ulcers, GERD, erosive esophagitis, and benign active gastric disease

– Long-term treatment of pathological hypersecretory conditions


– Acid labile, rapidly absorbed in the GI tract

– Metabolized in the liver and excreted in the urine


Proton Pump Inhibitors (cont.)Proton Pump Inhibitors (cont.)


– Allergy

• Caution


• Adverse Effects

– CNS effects

• Dizziness, headache, asthenia, vertigo, insomnia, apathy


Proton Pump Inhibitors (cont.)Proton Pump Inhibitors (cont.)

• Adverse Effects (cont.)

– GI Effects

• Diarrhea, abdominal pain, and tongue atrophy

– Upper respiratory tract symptoms

• Cough, stuff nose, hoarseness, and epistaxis

– Other

• Rash, alopecia, pruritis, dry skin, back pain, and fever


Antipeptic AgentAntipeptic Agent• Actions

– Forms an ulcer-adherent complex at duodenal ulcer sites, protecting the sites against acid, pepsin, and bile salts

• Indications

– Promote ulcer healing


– Rapidly absorbed, metabolized in the liver, and excreted in feces


– Allergy

– Renal failure


Antipeptic Agent (cont.)Antipeptic Agent (cont.)• Caution


• Adverse Effects

– GI effects – Constipation, diarrhea, nausea, indigestion, gastric discomfort, dry mouth

– Dizziness

– Sleepiness

– Vertigo

– Skin rash

– Back pain


Antipeptic Agent (cont.)Antipeptic Agent (cont.)


– Aluminum salts

– Phenytoin, fluoroquinolone, or penicillamine


ProstaglandinProstaglandin• Actions

– Inhibits gastric acid secretion and increases bicarbonate and mucous production in the stomach

• Indications

– Prevention of NSAID-induced gastric ulcers

– Treatment of duodenal ulcers


– Rapidly absorbed from GI tract, metabolized in the liver, and excreted in the urine


– Pregnancy


Prostaglandin (cont.)Prostaglandin (cont.)

• Caution

– Lactation

• Adverse Effects

– GI effects – Nausea, diarrhea, abdominal pain, flatulence, vomiting, dyspepsia, and constipation

– GU effects – Miscarriages, excessive bleeding, spotting, cramping, hypermenorrhea, dysmenorrhea, and other menstrual disorders


QuestionQuestion

Please answer the following statement as true or false.

There is a drug-drug interaction between the antipeptides and penicillin.


AnswerAnswer

False

Rationale: Drug-to-drug interactions include aluminum salts, phenytoin, fluoroquinolone, or penicillamine.


Patients Who May Require Digestive Enzyme Supplements

Patients Who May Require Digestive Enzyme Supplements

• Saliva Supplements

– Stroke

– Salivary gland disorder

– Extreme surgery of the head and neck

• Pancreatic Enzyme Supplements

– Common duct problems

– Pancreatic disease

– Cystic fibrosis


Digestive EnzymesDigestive Enzymes

• Actions

– Saliva substitute – Contains electrolytes and carboxymethylcellulose to act as a thickening agent in dry mouth conditions

– Pancreatic enzymes are replacement enzymes that help the digestion and absorption of fats, proteins, and carbohydrates

• Indications

– Replacement therapy


Digestive Enzymes (cont.)Digestive Enzymes (cont.)


– Saliva – Allergy

– Pancreatic enzymes - Allergy

• Caution

– Saliva – CHF, hypertension, or renal failure

– Pancreatic enzyme – Pregnancy and lactation


Digestive Enzymes (cont.)Digestive Enzymes (cont.)

• Adverse Effects

– Saliva – Complications from abnormal electrolytes – increased levels of magnesium, sodium, or potassium

– Pancreatic enzyme – GI irritation, nausea, abdominal cramps, and diarrhea


Use of Agents Affecting Gastrointestinal Secretions Across the Lifespan

Use of Agents Affecting Gastrointestinal Secretions Across the Lifespan


Prototype Histamine-2 (H2) AntagonistsPrototype Histamine-2 (H2) Antagonists


Prototype AntacidsPrototype Antacids


Prototype Proton Pump InhibitorsPrototype Proton Pump Inhibitors


Prototype Digestive EnzymesPrototype Digestive Enzymes


QuestionQuestion

What H2 antagonist has been associated with antiandrongenic effects?

A. Famotidine

B. Cimetidine

C. Nizatidine

D. Ranitidine


AnswerAnswer

B. Cimetidine

Rationale: Cimetidine was the first drug in this class to be developed. It has been associated with antiandrongenic effects, including gynecomastia and galactorrhea.


Nursing Considerations for Histamine-2 (H2) Antagonists

Nursing Considerations for Histamine-2 (H2) Antagonists

• Assessment: History and Physical Exam

• Nursing Diagnosis

• Implementation

• Evaluation


Nursing Considerations for AntacidsNursing Considerations for Antacids



• Implementation

• Evaluation


Nursing Considerations for Proton Pump Inhibitors

Nursing Considerations for Proton Pump Inhibitors



• Implementation

• Evaluation


Nursing Considerations for Antipeptic Agent

Nursing Considerations for Antipeptic Agent



• Implementation

• Evaluation


Nursing Considerations for Prostaglandin Nursing Considerations for Prostaglandin



• Implementation

• Evaluation


Nursing Considerations for Digestive Enzymes

Nursing Considerations for Digestive Enzymes



• Implementation

• Evaluation

Ppt chapter 57

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