1) Neutralize acid.

2) Decrease acid production.

3) Increase mucosal resistance.

Antacid.

MECH: Reacts with HCl forming calcium chloride and carbonic acid, raising pH. High pH reduces proteolysis of pepsin and reduces damaging effect of acid.

USE: Relieves pain. Heals ulcer faster than placebo. Requires high dosage; best taken 1 hr. after meal.

TOX: Constipating. Milk-alkali syndrome, nephrocalcinosis, rebound acidity, digitalis antagonism.

Antacid.

MECH: Raises pH. High pH reduces proteolysis of pepsin and reduces damaging effect of acid.

USE: Relieves pain. Heals ulcer faster than placebo. Requires high dosage; best taken 1 hr. after meal.

TOX: Rarely used due to systemic alkalosis. Enhances effect of amphetamine, quinidine and cinchophen.

Magnesium Hydroxide and Magnesium Carbonate

(Maalox, Mylanta, Gelusil, Riopan)

Antacid.

MECH: Reacts with HCl forming calcium chloride and carbonic acid, raising pH. High pH reduces proteolysis of pepsin and reduces damaging effect of acid.

USE: Relieves pain. Heals ulcer faster than placebo. Requires high dosage; best taken 1 hr. after meal.

TOX: May cause Magnesium toxicity in the presence of renal disease. Diarrhea, hypokalemia, iron deficiency due to complexing in gut.

Aluminum hydroxide

(Alternagel, Amphoijel)

Antacid.

MECH: Reacts with HCl forming aluminum chloride and water, raising pH. High pH reduces proteolysis of pepsin and reduces damaging effect of acid. Aluminun chloride forms aluminum phosphate in intestines which is non-absorbable, therefore it's not likely to disturb the serum electrolytes or serum pH.

USE: Relieves pain. Heals ulcer faster than placebo. Also exerts a protective effect on mucosa. Requires high dosage; best taken 1 hr. after meal. Good for renal failure patients (unload phos).

TOX: Constipation, phosphate depletion, weakness, anemia, tetany, apnea; delayed gastric emptying; concretions--fecaloma, colonic perforation and stercoral peritonitis; encephalopathy; impaired absorption of many drugs--tetracycline, digoxin, INH.

Anticholinergic.

MECH: Vagotomy-effect. Reduces hydrochloric acid secretion.

AE: Dry mouth, blurred vision, atony of bladder, constipation, drowsiness and mental confusion.

CONTRA: Pyloric obstruction, hiatal hernia, peptic esophagitis.

Anticholinergic.

MECH: Vagotomy-effect. Reduces hydrochloric acid secretion.

AE: Dry mouth, blurred vision, atony of bladder, constipation, drowsiness and mental confusion.

CONTRA: Pyloric obstruction, hiatal hernia, peptic esophagitis.

Anticholinergic.

MECH: Vagotomy-effect. Reduces hydrochloric acid secretion.

AE: Dry mouth, blurred vision, atony of bladder, constipation, drowsiness and mental confusion.

CONTRA: Pyloric obstruction, hiatal hernia, peptic esophagitis.

MECH: Blockage of Histamine H2 receptor on parietal cells lowering acid secretion. Inhibit 50-80% of acid secretion.

USE: Healing of ulcers. Prophylaxis of stress ulcers (in patients).

AE: Headache, lethargy, confusion, depression, hallucinations. Binds CYT P450 interfering with metabolism of theophylline, warfarin, dilantin or lidocaine.

MECH: Blockage of Histamine H2 receptor on parietal cells lowering acid secretion. Inhibit 50-80% of acid secretion.

USE: Healing of ulcers. Prophylaxis of stress ulcers (in patients).

AE: Headache, lethargy, confusion, depression, hallucinations. Binds CYT P450 interfering with metabolism of theophylline, warfarin, dilantin or lidocaine.

MECH: Blockage of Histamine H2 receptor on parietal cells lowering acid secretion. Inhibit 50-80% of acid secretion.

USE: Healing of ulcers. Prophylaxis of stress ulcers (in patients).

AE: Headache, lethargy, confusion, depression, hallucinations.

MECH: Blockage of Histamine H2 receptor on parietal cells lowering acid secretion. Inhibit 50-80% of acid secretion.

USE: Healing of ulcers. Prophylaxis of stress ulcers (in patients).

AE: Headache, lethargy, confusion, depression, hallucinations. Binds CYT P450 interfering with metabolism of theophylline, warfarin, dilantin or lidocaine.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia. Strong inhibitor of P450 delaying metabolism of diazepam, warfarin, and dilantin. Gastric hyperplasia--not good for long-term usage.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia. Inhibitor of P450 delaying metabolism of diazepam, warfarin, and dilantin. Gastric hyperplasia--not good for long-term usage.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia. Moderate inhibitor of P450 delaying metabolism of diazepam, warfarin, and dilantin. Gastric hyperplasia--not good for long-term usage.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia. Inhibitor of P450 delaying metabolism of diazepam, warfarin, and dilantin. Gastric hyperplasia--not good for long-term usage.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia. Does NOT inhibit P450 delaying metabolism of diazepam, warfarin, and dilantin--good for polypharmacy patients. Gastric hyperplasia--not good for long-term usage.

MECH: Inhibition of H⁺/K⁺ ATPase on activated parietal cells.

USE: Administer on empty stomach 30mins prior to meal so that parietal cells are in active state. Better pain relief and faster healing thatn with H2 antagonists.

TOX: Headache, gynecomastia.  Inhibitor of P450 delaying metabolism of diazepam, warfarin, and dilantin. Gastric hyperplasia--not good for long-term usage.

1) NSAID use.

2) Helicobacter pylori.

3) Zollinger-Ellison Syndrome (gastrinoma).

MECH: Crystals formed in acidic environment coat ulcer crater.

USE: Lowers recurrence rate of ulcer better than H2 antagonists.

TOX: Causes black discoloration of tongue or stool (can be confused with hemorrhage).

MECH: An aluminum hydroxide complex of sucrose binds to ulcerated tissue when activated by acid environment.

USE: As effective as H2 antagonist for healing and prevention of relapse.

TOX: Constipation, aluminum toxicity in renal failure.

MECH: Prostaglandin agonist increasing mucosal secretions, bicarbonate secretion, decreasing acid production--protecting surface of stomach.

USE: Prevention of NSAID-related gastric ulcers.

Triple therapy:

1) PPI or ranitidine bismuth citrate.

2) Metronidazole.

3) Tetracycline or Amoxicillin.

1) Impaired lower esophageal sphincter.

2) Hypersecretion of acid.

3) Decreased acid clearance (impaired peristalsis; abnormal saliva production).

4) Delayed gastric emptying/duodenogastric reflux.

MECH: Peripheral dopamine antagonist increases gastric motility. CNS dopamine antagonism is anti-emetic.

USE: GERD--decreases acid in stomach. Outlet obstruction - stimulates upper GI motility without stimulating gastric, biliary or pancreatic secretions. Anti-emetic.

TOX: Tremor (extrapyramidal symptoms).

MECH: Seratonin receptor agonist increases gastric motility.

USE: GERD--decreases acid in stomach.

Phenothiazine - neuroleptic class.

MECH: Acts on Chemo Receptor Trigger Zone (CRTZ) in medulla (vomiting center). CNS interaction with dopaminergic receptor - antagonist.

USE: Antiemetic.

AE: Torticollis.

Phenothiazine - neuroleptic class.

MECH: Antihistamineic (H1) receptor, anticholinergic.

USE: Antiemetic.

AE: Somnolence.

Benzamide derivative.

MECH: Unknown but acts on CRTZ.

USE: Antiemetic.

AE: Extrapyramidal symptoms--not as severe.

MECH: Supress the CRTZ by probably anticholinergic mechanism.

USE: Anti-emetic.

Seratonin receptor antagonists.

MECH: 5-HT3 receptor blockade.

USE: Anti-emetic.

AE: Headache, dizziness, somnolence.

Seratonin receptor antagonists.

MECH: 5-HT3 receptor blockade.

USE: Anti-emetic.

AE: Headache, dizziness, somnolence.

Seratonin receptor antagonists.

MECH: 5-HT3 receptor blockade.

USE: Anti-emetic.

AE: Headache, dizziness, somnolence.

MECH: Promotilty drug.

USE: Outlet obstruction and/or loss of gastric tone (DM).

Opioid agonist.

MECH: Increase rectal tone and distrupt peristalsis via mu receptor.

USE: Anti-diarrheal.

Opioid agonist.

MECH: Increase rectal tone and distrupt peristalsis via mu receptor allowing gut time to absorb fluid.

USE: Anti-diarrheal.

Opioid agonist.

MECH: Increase rectal tone and distrupt peristalsis via mu receptor allowing gut time to absorb fluid.

USE: Anti-diarrheal.

Colloid.

MECH: Absorbs water in intestines.

USE: Anti-diarrheal.

AE: Doesn't prevent dehydration.

Pectin.

 MECH: Absorbs water in intestines.

USE: Anti-diarrheal.

AE: Doesn't prevent dehydration.

MECH: Works on lumenal side. Anti-inflammatory agent derivative of salicylic acid.

USE: Inflammatory bowel disease (Crohn's, ulcerative colitis, etc.)

MECH: Works on lumenal side. Anti-inflammatory agent derivative of salicylic acid. Cleaved to release salicylic acid.

USE: Inflammatory bowel disease (Crohn's, ulcerative colitis, etc.)

MECH: Works on lumenal side. Anti-inflammatory agent derivative of salicylic acid. As good as sulfasalazine but with less toxicity.

USE: Inflammatory bowel disease (Crohn's, ulcerative colitis, etc.).

Immunosuppressive agent.

MECH: Anti-metabolite - interferes with DNA synthesis.

USE: Ulcerative colitis; Crohn's disease.

Immunosuppressive agent.

MECH: Anti-TNF alpha antibody.

USE: Crohn's; ulcerative colitis.

Immunosuppressant.

MECH: Supresses T helper and T suppressor lymphocytes.

USE: Crohn's; ulcerative colitis.

MECH: Anticholinergic drug prevents colon spasm.

USE: IBS.

MECH: Anticholinergic drug prevents colon spasm.

USE: IBS.

MECH: Seratonin antagonist at 5HT3 receptor.

USE: Diarrheal prominant IBS. (Also depression).

AE: Constipation; ischemic bowel.

MECH: 5HT4 receptor agonist.

USE: Constipation predominant IBS.