Drugs for Gastrointestinal and Related Diseases Chapter 10 Drugs for Gastrointestinal and Related Diseases

Chapter 10 Definitions Gastrointestinal (GI) tract GI transit time GERD Peptic Disease Ulcer

The Gastrointestinal System Gastrointestinal (GI) tract is a continuous tube Starts at mouth  pharynx  esophagus  stomach  small intestine  large intestine  ends at anus Digestive and absorptive process take place in the GI tract

GI Transit Time Speeding up transit time = less absorption Slowing transit time = more absorption

Gastroesophageal Reflux Disease (GERD) Symptoms Radiating burning or pain in chest Acid taste Recurrent abdominal pain Meal-related esophagitis due to reflux (backflow) of acidic stomach contents through incompetent esophageal sphincter

H2 Histamine Receptor Antagonists Block gastric acid and pepsin secretion Blocks action of histamine in the stomach- decreasing the production of acid All available OTC in some strengths Bedtime dose is most important

Therapeutic Uses of ranitidine (Zantac, Zantac 75) Active duodenal ulcers and benign gastric ulcers Long-term prevention of duodenal ulcers Gastric hypersecretory states GERD Postoperative ulcers Preventing stress ulcers Upper GI bleeding

Therapeutic Uses of ranitidine (Zantac, Zantac 75) Precautions: Pregnancy-B Do not crush, chew or break Side-Effects: Increase risk of Pneumonia HA, dizziness, insomnia, decreased sex drive, swollen breast-men, nausea, vomiting, diarrhea, constipation

Dispensing Issues of Ranitidine Look-alike and sound-alike Ranitidine (H2 antagonist) Amantadine (for flu) Rimantadine (antiviral)

Dispensing Issues of Zantac Look-alike and sound-alike Zantac Xanax (antianxiety)

Proton Pump Inhibitors An enzyme maintains acidity in gastric secretions by pumping Acidic hydrogen ions (protons) into stomach Nonacidic potassium ions out Proton pump inhibitors (PPIs) block this enzyme, reducing stomach acidity PPIs must be taken daily

omeprazole (Prilosec) Indicated for short-term treatment of esophagitis, GERD, and hypersecretory conditions Take before meals Also indicated for peptic disease caused by bacterium Helicobacter pylori (H. pylori)

omeprazole (Prilosec) Precautions: Pregnancy Cat C Do not crush, chew or break Side Effects: Fever Cold symptoms Stomach pain Nausea, vomiting, diarrhea headache

lansoprazole (Prevacid) Indicated for short-term therapy of ulcers and esophagitis Indicated for long-term treatment of hypersecretory disorders and Zollinger-Ellison syndrome (hypersecretion from a tumor)

lansoprazole (Prevacid) Not for immediate relief of heartburn Precautions: 1Q24H for 14days, 4 months between treatments Pregnancy Cat. B Do not crush, chew or break Side Effects: Headache, nausea, stomach pain, diarrhea, constipation

esomeprazole (Nexium) Very similar to Prilosec, but metabolized slower which increases duration of acid suppression Take on an empty stomach

esomeprazole (Nexium) Not for immediate relief of heartburn 4-8 weeks full glass of water, 1 hr before food Precautions: Severe liver disease, low levels of magnesium Pregnancy Cat B Side Effects: Headache, drowsiness, diarrhea, nausea, stomach pain, constipation, dry mouth

Agents for GERD Combinations calcium carbonate-famotidine-magnesium hydroxide (Pepcid Complete) lansoprazole-naproxen (Prevacid NapraPAC)