Top 200 Drugs Section 3: GI Agents

Stomach pH

1 to 3

Small intestine pH

6 to 7.5

Large intestine pH

5.5 to 7

Heartburn

When stomach acid washed back up into the esophagus

GERD

Gastroesophageal Reflux Disease (Acid reflux) - chronic condition

Causes of GERD

foods (high fat foods, spicy food, caffeine), alcohol, large meals, certain exercises, medications

Medicine used to treat GERD

antacids, H2 antagonists, Proton Pump Inhibitors (PPI)

Antacids

neutralize stomach acid

What formulation of antacids work more quickly

liquid formulations

Antacid examples

Maalox, Mylanta, Rolaids

H2 antagonists

histamine is a chemical that tells the stomach to produce acid

• this is the 1st step in the production of acid in the stomach

this drug works within 1 hr and lasts 22 hrs

QD or BID

Zantac

ranitidine

Pepcid

famotidine

Tagamet

cimetidine

Proton Pump Inhibitors (PPI)

Shut down the cells in the stomach that pump acid molecules

takes 24 hrs to work but can last 72 hrs

QD or BID

Aciphex

rabeprazole

Nexium

esomeprazole

Prevacid

lansoprazole

Prilosec

omeprazole

Protonix

pantoprazole

Stomach (peptic) ulcers

sores on inner lining of stomach

Most common cause for stomach ulcers

bacteria called Helicobacter pylori

Treatment of stomach ulcers

H2 antagonist, PPIs, and antibiotics

Medical term for vomiting

emesis

Anti-emetics

work to block neurotransmitters that set off the complex vomiting reflex

Zofran

ondansetron

Phenergan

promethazine

Acute diarrhea

lasts 1 or 2 days, goes away on its own

Chronic diarrhea

lasts several days or weeks

Treating diarrhea

needs to slow down motility of the gut

Imodium

loperamide

Lomotil

diphenoxylate/atropine

Constipation

bowel movement less than 3 times per week

Medications used to treat constipation

4 types of laxatives

• Bulk forming

• Softeners

• Hydrating

• Stimulant

Bulk forming laxatives

gentlest, useful for maintaining regularity, take w lots of water, works in 12-72 hrs

Softener laxatives

increase water content of stool and lubricate passage, take w lots of water and useful for occasional use. works overnight (12+ hrs)

Hydrating laxatives

works in 1/2 -5 hrs, can cause dehydration and cramping

two types: saline and osmotic

Saline hydrating laxatives

attract/retain water in intestine

Osmotic hydrating laxatives

attract/retain water in colon; used for irrigation prior to colonoscopy

Stimulant laxatives

works on intestinal mucosa to stimulate the contraction of muscles, causes cramping and dehydration and are for short term use only

Miralax

polyethylene glycol (PEG)

Colace

docusate sodium

Dulcolax

bisacodyl

Bentyl

dicyclomine

Reglan

metoclopramide

What medication is used to treat IBS

dicyclomine as an anticholinergic - reduces contractions in intestinal muscles that can cause cramping