GI Pharmacology for Antacids and H2-Blockers

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In this lecture, we will be going over gastrointestinal (GI) medications that are usually used for peptic ulcer disease, gastritis, heartburn or basically the overproduction of acid. To counter the effects of these conditions on the body and bring down acid production three types of medications that are given.

The Rule of Three

Just like any other medications given – insulins or pain medications, there’s always the rule of three. The rule of three is composed of therapeutic approaches ranging from mild, moderate, and severe. This is because, when considering pharmacology, the medical team always focuses on different treatment angles to deal with a specific manifestation.

For example, if there is increased blood pressure, a diuretic can be given to decrease the volume and relieve pressure from the heart. Then a beta-blocker to block the beta-adrenergic agents and calcium channel blocker to soften the heart are given. There are a lot of angles that are taken into consideration when dealing with increased blood pressure; this is similar when dealing with gastrointestinal issues.

The Antacids

Antacids or anti-acids are usually the first lines of approach when someone has an overproduction of acids. Antacids come in the form of Tums. Tums are calcium-based types of buffers decreasing acid production. You can think of Tums as the alkaline antacid that serves as fire extinguishers which put out the burning flame inside your GI tract.

Heartburn, also known as gastroesophageal reflux disease (GERD), is mainly a reflux disorder that causes pain mainly at the orifice between the stomach and esophagus. To neutralize the fires burning within antacids are given.

The good thing about antacids is that they work as quickly as 20 minutes. Make sure that before ingesting antacids, you have taken something that’s upsetting or harsh to the GI tract, for example, spices, meats, coffee, and dairy. After eating one of these leading causes of increased acid production, antacids must follow immediately. You can also compare antacids to fast-acting insulins with regards to their onset.

Peptic Ulcer

Before getting into the mechanism of action of H2 blockers, we will take a quick second to discuss peptic ulcers.

There are gastric parietal cells inside the GI tract that secrete acid which comes in the form of hydrochloric acid (HCL). Remember, hydrogen ions are very acidic. Histamines are then released causing inflammation, irritation, and breakdown which then leads to peptic ulcer disease. A peptic ulcer is just a fancy term of a hole in the lining of the stomach – perforation of the stomach. This condition is dangerous because the acids will get out and the peritoneal cavity will become infected, causing severe bleeding.

H2 Blockers

To prevent peptic ulcers from happening, and to bring down inflammation and protect the stomach lining or the GI tract, in general, the doctors will prescribe H2 blockers or histamine 2 blockers.

H2 blockers decrease HCL production which thereby decreases stomach acids. If your client has alcohol hypersensitivity, you have to instruct him or her to avoid alcohol when taking H2 blockers.

Recall Tip

How can you remember what H2 blockers are?

Think of H2 blockers as football players that are tasked as linemen to block the opposing team from attacking the quarterback. Now, football players have dirty jersey due to the sport, so their jerseys need Tide or “-tidine” to tidy up their soiled articles. And because football players love to play loud music, you will hear someone say, “Turn down the volume,” which can also be interpreted as H2 blockers decreasing the volume of acid being produced inside the stomach. Hope this works for making you remember what H2 blockers do and its suffix.

On our next lecture, we’ll be focusing on the third medication used for increased acid production – proton-pump inhibitor (PPI). See you there!