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Have you ever heard that a little bit of knowledge is a dangerous thing? When we look at the history of treating stomach peptic ulcers, the importance of thoroughly understanding a medical condition in order to treat it effectively becomes obvious.

 So, what is a peptic ulcer?

It’s a hole in the mucous membrane of the stomach. This hole allows the gastric acid in your stomach to reach the stomach lining, irritating it and causing dull or burning pain*. If left untreated, peptic ulcers can result in severe bleeding and even death. However, there have been effective treatments around for ulcers since the 1970’s.

When pharmaceutical companies first looked at developing medicines for treating stomach ulcers, they were thought to be caused by stress, spicy food or alcohol. Nowadays, we know otherwise, but these factors can make the symptoms of a peptic ulcer worse.

It was understood then, and still is today, that gastric acid makes peptic ulcers worse. So the first type of medication developed for treating peptic ulcers were H2 Histamine antagonists.

Histamine, a hormone, can cause the release of gastric acid from parietal cells in the stomach. This happens when histamine interacts with a special type of receptor on these cells called the H2 receptor. H2 Histamine antagonists such as cimetidine (trade name Tagamet) bind to H2 receptors without stimulating gastric acid release, blocking Histamine from binding and so decreasing the amount of gastric acid produced in the stomach.

Cimetidine, marketed in the UK in 1976, was the first really effective antiulcer drug. No longer was it necessary to swallow large amounts of antacids (bases such as sodium bicarbonate or calcium carbonate) to try to neutralize gastric acid. No longer was surgery the only way to get rid of a peptic ulcer.

As effective as drugs like cimetidine were, a new and superior class of medication to treat ulcers was developed in the 1980’s. These new drugs are called Proton Pump Inhibitors (PPI’s).

All gastric acid production is done in the parietal cells through an enzyme complex called a proton pump. A Proton Pump Inhibitor such as omeprazole (trade name Losec) is a weak base. When it reaches the highly acidic openings to the parietal cells, it is ionized to an active form and binds irreversibly to the proton pump by forming a covalent bond to a free Histidine residue. This prevents formation of hydrochloric acid, the main component of gastric acid.  

Drugs like cimetidine prevent histamine from stimulating the proton pump to produce hydrochloric acid, blocking one stimulatory pathway. But there are other ways to activate the proton pump. Drugs like omeprazole prevent the proton pump from producing any hydrochloric acid. This is clearly a better way to reduce the amount of gastric acid in the stomach near a peptic ulcer.

However, one of the puzzling aspects of stomach ulcers is their tendency to reoccur after finishing a course of medication.

This was explained to be because of a microorganism called H. pylori in the stomach. Scientific evidence has implicated H. pylori infection as one of the main causes of peptic ulcers. H. pylori are associated with inflammation of the stomach, as they can produce cytotoxins that have been specifically linked to peptic ulceration**.

Treatment of H. pylori infection is done using antibiotics. Combination therapy of a PPI and at least two bacterial agents has been shown to eradicate H. pylori in over 90% of ulcers and significantly reduce the likelihood of reoccurrence of a peptic ulcer***.

So from an approach aimed at preventing aggravation of an ulcer by reducing the amount of gastric acid in the stomach, medicine is now trying to kill off one of the main cause of ulcers: H. pylori.

It is worth mentioning briefly that the other main cause of ulcers is non-steroidal anti-inflammatories (NSAIDS) such as asprin. NSAIDS prevent a special enzyme called COX-1 from working. This enzyme produces a chemical messenger to stop acid secretion and protect the walls of the stomach.

Please note: This information is not designed to help anyone make self-diagnoses. There is a reason our doctors train for at least 6 years before they are allowed to practice medicine. The human body is wonderfully made and a complex biological environment. Stomach pain can be an indicator of many different medical problems.

*See website: US Department of Health and Human Services (2010) What I need to know about Peptic ulcers, available: http://digestive.niddk.nih.gov/ddiseases/pubs/pepticulcers_ez/                  Accessed 12/3/12.

**See website: University of Oxford Medical Sciences Division (1995) Helicobacter Pylori and Peptic Ulcer, available: http://www.medicine.ox.ac.uk/bandolier/bandopubs/hpyl/hpall.html#background  Accessed 12/3/12.

 ***See book: Patrick, G. (2009) An Introduction to Medicinal Chemistry, 4th Ed., New York: Oxford University Press. pp642-673

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