H2-receptor antagonists
- H2-receotor antagonists (H2 Blockers) suppress gastric acid secretion.
- H2 Blockers work by blocking signals generated by histamine receptors on cells that are responsible for acid secretion.
- H2 blockers begin working within an hour. H2 Blockers, however, usually only work up to 12 hours.
- H2 are capable of healing duodenal ulcers, relieving symptoms, and preventing complications. They are well tolerated and have low side effects
- GERD that occurs 30-60 min PC and when a patient bends over or lies down, results from irritation of the esophagus by stomach acid should be treated with acid suppression therapy such as antacids (neutralizes stomach acid) or histamine -2 receptor antagonist or PPI (Prilosec).
- H2 blockers are given after meals and HS.
- Do not take within 2 hrs. of antacid.
- Do not use PPI and H2 together.
- H2 are less expensive and are also effective. If patient does not see results within a few days, increase dosage of med or change from H2 to PPI.
- Not very effective for healing or preventing gastric ulcers, but do prevent duodenal ulcer.
- Monitor liver enzymes and platelets when taking H2.
- Nizatidine (Axid) is a good substitute for Tagamet.
- Excessive use of histamine H-2 receptor antagonists leads to pharmacological tolerance and decrease effectiveness over time.
- Pylori infection, NSAIDs and Smoking all contributes to Peptic Ulcer formation.
- The Urea Breath test and the Stool Antigen tests are ordered to detect Helicobacter Pylori (H.Pylori).
- PUD (peptic ulcer) caused by helicobacter Pylori is treated with: clarithromycin (Biaxin), Amoxicillin, PPI (Prilosec).
- Cimetidine (Tagamet) and Calcium Channel Blockers (CCBs) have a drug interaction. Because of this, the CCB’s may be increased because cimetidine (Tagamet) may decrease the metabolism of CCBs.
- Cimetidine (Tagamet) is not used much due to many DDI (Coumadin, theophylline, lidocaine).
- Dines are H2 receptors and the prazole are PPI.
- SIDE EFFECTS: HA, dizziness, fatigue, somnolence, and either diarrhea or constipation. These side effects are most likely to appear in the elderly and/or patients with decreased renal function, and metabolic/endocrine changes, such as: gynecomastia, low sperm count and CNS changes (disorientation, hallucinations).
H2-receptor antagonists:
Cimetidine (Tagamet)
Famotidine (Pepcid)
Nizatidine (Axid)
Ranitidine (Zantac)