Final

The GI system is the only system in the body open to the external environment

• Begins at the mouth
• Progresses through the esophagus, stomach, and small and large intestines
• Ends at the anus

• Pancreas
• Liver
• Gallbladder

• Secretion: Of enzymes, acid, bicarbonate, and mucus
• Absorption: Of water and almost all of the essential nutrients needed by the body
• Digestion: Of food into usable and absorbable component
• Motility: Movement of food and secretions through the system

• Saliva
• Mucus
• Acid and Digestive Enzymes (Gastin, Pepsin)
• Secretin
• Sodium Bicarbonate
• Pancreatic Enzymes, Other Lipases, and Amylases
• Bile
• Endocrine Hormones

• Dietary Excess
• Stress
• Hiatal Hernia
• Esophageal Reflux
• Peptic Ulcer Disease
• Adverse Drug Effects

• 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

• 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

• 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
• 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

• Selectively block histamine-2 receptor sites
• This blocking leads to a reduction in gastric acid secretion and reduction in overall pepsin production
• Cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), ranitidine (Zantac)

Short-term treatment of active duodenal ulcer or benign gastric ulcer Treatment of pathological hypersecretory conditions such as Zollinger–Ellison syndrome

Known allergy

• Pregnancy or lactation
• Renal or hepatic dysfunction

• Prototype: Cimetidine
• GI effects: diarrhea or constipation
• CNS effects: headache, dizziness, confusion
• Cardiac arrhythmias and hypotension
• Reproductive system – gynecomastia, impotence

Slows metabolism of warfarin, phenytoin, beta blockers, alcohol, quinidine, lidocaine, theophylline, chloroquine, benzodiazepines, nifedipine, pentoxifylline, tricyclics, procainamide, and carbamazepine

• Administer with or before meals and bedtime
• Monitor cardiac status continually if administering IV
• Decreased dose in renal/hepatic disease
• Do NOT administer and antacid and ranitidine together
• Cimetidine is NOT for < 16 years, nizatidine and ranitidine are NOT for children

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

• Neutralize stomach acid by direct chemical reaction
• sodium bicarbonate (Bell-ans), calcium carbonate (Tums), magnesium salts (MOM), aluminum salts (Amphojel), magaldrate (Riopan)

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

Allergy

• Any condition that can be exacerbated by electrolyte imbalance
• GI obstruction

• Prototype: Sodium Bicarbonate
• Monitor acid-base levels and electrolytes
• Rebound acidity
• Alkalosis – n/v, h/a, irritability, muscle twitching, coma
• Hypercalcemia
• Constipation or diarrhea
• Hypophosphatemia w/aluminum salts
• Sodium bicarbonate – fluid retention, heart failure

Affect the absorption of many other drugs

• Administer 1 hour before or 2 hours after other medications
• Chew tablets thoroughly with glass of water
• Monitor electrolytes
• Monitor for diarrhea or constipation
• Teach acid rebound

• Act at specific secretory surface receptors to prevent the final step of acid production and thereby decrease the level of acid in the stomach
• omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid), dexlansoprazole (Kapidex), pantoprazole (Protonix), rabeprazole (Aciphex)

• Short-term treatment of active duodenal ulcers, GERD, erosive esophagitis, and benign active gastric disease
• Long-term treatment of pathological hypersecretory conditions

Allergy

Pregnancy or lactation

• Prototype: Omeprazole
• CNS effects:
• Dizziness, headache, asthenia, vertigo, insomnia, apathy
• GI Effects:
• Diarrhea, abdominal pain, and tongue atrophy
• Upper respiratory tract symptoms:
• Cough, stuff nose, hoarseness, and epistaxis
• Rash, alopecia, pruritis, dry skin, back pain, and fever

• Administer before meals
• Do NOT open, chew, crush capsules
• Monitor for diarrhea or constipation
• Teach to eat small frequent meals
• Medical follow-up after 4- 6 weeks
• Administer w/ antibiotics for H. pylori

• Forms an ulcer-adherent complex at duodenal ulcer sites, protecting the sites against acid, pepsin, and bile salts
• Inhibits pepsin activity to prevent further breakdown
• sulcralfate (Carafate)

Promote Ulcer Healing

• Allergy
• Renal Failure

Pregnancy or lactation

• GI effects:
• Constipation, diarrhea, nausea, indigestion, gastric discomfort, dry mouth
• Dizziness, vertigo, sleepiness, skin rash, back pain

• Aluminum salts
• Phenytoin, fluoroquinolone, or penicillamine

• Administer on empty stomach, 1 hour before or 2 hours after meals and bedtime
• Monitor for GI pain, constipation
• Do NOT administer antacids or antibiotics within 30 minutes of sulcralfate
• Provide frequent oral care
• Increase fluid & fiber in diet – small, frequent meals

• Inhibits gastric acid secretion and increases
• bicarbonate and mucous production in the stomach
• misoprostol (Cytotec) – PGE1

Pregnancy

Lactation

• GI effects: Nausea, diarrhea, abdominal pain, flatulence, vomiting, dyspepsia, and constipation
• GU effects: Miscarriages, excessive bleeding, spotting, cramping, hypermenorrhea, dysmenorrhea, and other menstrual disorders

• Administer during NSAID therapy
• Administer four times/day – w/ meals, bedtime
• Provide small, frequent meals, increase fluids
• Pregnancy category X
• Check pregnancy test w/in 2 weeks of beginning therapy
• Assess menstrual activity – begin on 2nd or 3rd day of menstrual period
• Teach to use barrier contraceptives
• Provide written and oral information on pregnancy risks
• Teach risks of menstrual disorders and pain, miscarriage risk, excessive bleeding

• Saliva Supplements:
• Stroke
• Salivary gland disorder
• Extreme surgery of the head and neck
• Pancreatic Enzyme Supplements:
• Common duct problems
• Pancreatic disease
• Cystic fibrosis

• Saliva substitute: Contains electrolytes and carboxymethylcellulose to act as a thickening agent in dry mouth conditions
• Salivart, MouthKote
• Pancreatic enzymes are replacement
• enzymes that help the digestion and absorption of fats, proteins, and carbohydrates
• Pancrelipase (Pancrease, Creon)
• LactAid for lactose intolerance

Replacement Therapy

• Saliva: Allergy
• Pancreatic enzymes: Allergy to pork

• Saliva: HF, hypertension, or renal failure
• Pancreatic enzyme: Pregnancy and lactation

• Prototype: Pancrelipase
• Saliva substitute: Complications from abnormal electrolytes – increased levels of magnesium, sodium, or potassium
• Pancreatic enzyme: GI irritation, nausea, abdominal cramps, and diarrhea

• Swish saliva substitute as needed
• Administer pancreatic enzymes with meals and snacks
• Avoid spilling pancreatic enzymes on skin
• Do NOT crush or chew pancreatic capsule
• Monitor for electrolyte imbalances

• 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