Pharmacology, part 36: Gastrointestinal Medications - Antiulcer Agents

September 10, 2021 Updated: November 08, 2021 8 min read

This article begins our look at gastrointestinal medications, starting with antiulcer agents. You’ll recognize many of the brand names of these drugs, but note that they fall into different categories, depending on how they work and when best to prescribe them.

You can follow along to this Nursing Pharmacology video series with our Pharmacology Flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.

Cool Chicken When you see this Cool Chicken, that indicates one of Cathy's silly mnemonics to help you remember. The Cool Chicken hints in these articles are just a taste of what's available across our Level Up RN Flashcards for nursing students!

Histamine 2 Receptor Antagonist - ranitidine (Zantac), famotidine (Pepcid)

Cool Chicken Ranitidine will help your stomach feel better when you dine. Many end in -dine.

Histamine 2 receptor antagonists, also known as H2-blockers include ranitidine (Zantac) and famotidine (Pepcid). These medications can be used to treat gastroesophageal reflux disease (GERD), as well as duodenal and gastric ulcers. They may also be prescribed for a rare disorder called Zollinger-Ellison syndrome, which causes excess gastric acid production.

H2-blockers should be administered with meals (“when you dine”) and at bedtime.

Ranitidine mode of action

The mode of action of this drug class is that it blocks H2 receptors in the stomach, reducing gastric acid secretion.

Ranitidine side effects

Side effects of H2-blockers are minimal and can include headache or GI upset.

Proton Pump Inhibitor - omeprazole (Prilosec), pantoprazole (Protonix)

Cool Chicken I’m going to take omeprazole and pray my ulcer pain goes away. Many end in -prazole.

Proton pump inhibitors, or PPIs, are a class of medication that includes omeprazole and pantoprazole. These medications are used to treat the same conditions as histamine-2 receptor antagonists. That means PPIs may be used to treat GERD, duodenal and gastric ulcers, and Zollinger-Ellison syndrome.

Omeprazole mode of action

Proton pump inhibitors' mode of action is to inhibit an enzyme, pepsinogen, that is required for gastric acid secretion. Pepsinogen is secreted into the gastric juice, which is secreted into the stomach. There, it is activated by stomach acid into the active protease pepsin. Pepsin is what aids the stomach's ability to digest proteins. Administering a PPI decreases gastric acid secretion.

Omeprazole side effects

The side effects of omeprazole can include GI upset and C. diff, also known as Clostridioides difficile or C. difficile. C. diff is a germ (bacterium) that causes severe diarrhea and colitis (an inflammatory reaction in the colon).

Long-term use of these medications may lead to bone fractures, as PPIs are reported to be associated with decreased bone mineral density (characteristic of osteoporosis).

Nursing care

Closely monitor the patient for diarrhea, cramping, and bloody stools.

Mucosal Protectant - sucralfate (Carafate)

Cool Chicken Sucralfate gets “sucked” down into ulcers.

Sucralfate (Carafate) is a mucosal protectant used in the treatment of duodenal ulcers. Studies show that mucosal protective agents (MPAs) can help treat intestinal lesions as mucus appears to play an important role in the protection of the inner lining of the intestinal tract.

Administering sucralfate

Administer sucralfate 1 hour before meals and at bedtime (4 times a day). It is important to increase the patient's intake of fluids and fiber when they are taking sucralfate.

Sucralfate mode of action

Sucralfate reacts with the stomach's acid to form a thick paste, which adheres to the ulcers.

Sucralfate side effects

The key side effect with sucralfate is constipation. This is why it is important to encourage the patient to increase their intake of fiber and fluids.

Antacids - aluminum hydroxide (Amphojel)

Cool Chicken Take Antacids After meals.

The next class of antiulcer agents is antacids. Among these is aluminum hydroxide (Amphojel). Antacids are used to treat peptic ulcer disease and GERD (gastroesophageal reflux disease). They may also be administered to lower phosphate levels in patients with chronic kidney disease, who should limit their intake of phosphorus, potassium, and sodium.

Administering antacids

Administer antacids after meals and at bedtime. Think, "A" for Antacids and "A" for After meals.

Note that it is very important never to give antacids at the same time as other medications — the best time to give antacids is one to two hours before or after other medications.

Aluminum hydroxide mode of action

Antacids work by neutralizing the stomach acid and by binding phosphate in the stomach.

Aluminum hydroxide side effects

One key side effect of antacids is constipation. Make sure that the patient is encouraged to increase their intake of fiber and fluids when taking antacids.

Prostaglandins - misoprostol (Cytotec)

Cool Chicken Me so pregnant, so I shouldn’t take misoprostol for prevention of gastric ulcers. FYI - OK for ripening the cervix during labor and delivery.

Prostaglandins are the last class of antiulcer agent. This includes misoprostol (Cytotec). Misoprostol is used to prevent gastric ulcers in patients taking NSAIDs. It also induces labor by ripening the cervix.

Misoprostol mode of action

The mode of action of misoprostol is to decrease stomach acid secretion and increase the production of protective mucus in the stomach. It also increases the production of bicarbonate, which helps thicken the mucus, allowing it to produce new cells.

When used for labor induction, misoprostol causes uterine contractions.

Misoprostol side effects

Side effects include dysmenorrhea (painful menstruation) and GI upset.

Misoprostol black box warning

Misoprostol carries a black box warning because it can cause a miscarriage, premature birth, and birth defects. So any time misoprostol is administered for ulcer prevention in a patient who could become pregnant, it is important to run a pregnancy test first.


Full Transcript

Hi, I'm Cathy, with Level Up RN. In this video, I'm going to start in on our coverage of gastrointestinal medications. So if you have our pharmacology second edition flashcards, definitely pull those out. We are in the green section so you can follow along. Specifically, in this video, I will be covering anti-ulcer agents. And at the end of the video, I'm going to provide you guys a quiz to test your understanding of some of the key facts I'll be covering in this video. So definitely stay tuned for that.

Histamine-2 receptor antagonist is the first drug class I'm going to cover. Medications that fall within this class include ranitidine and famotidine. These medications can be used to treat gastroesophageal reflux disease, so GERD, as well as duodenal and gastric ulcers, and also a rare disorder called Zollinger-Ellison syndrome, which causes excess gastric acid production. So the mode of action of this drug class is that it blocks H2 receptors in the stomach, and this reduces gastric acid secretion. Side effects are minimal. They can include a headache as well as GI upset. The way I remember these medications and what they're for, if you look at the drug name-- so ranitidine and famotidine, they end in that dine, spelled D-I-N-E like dine. So I remember that if you take your ranitidine, or dine, it will help your stomach feel better when you dine. So when you eat. So hopefully that's helpful for you as well.

Next, we have our proton pump inhibitors or PPIs. Medications that fall within this class include omeprazole, as well as pantoprazole. And these medications are used to treat the same conditions as our histamine-2 receptor antagonists. So we can use PPIs to treat GERD, to treat ulcers, as well as Zollinger-Ellison syndrome. So PPIs inhibit an enzyme that is required for gastric acid secretion. So we have decreased gastric acid secretion with PPIs. Side effects can include GI upset, C. diff, and with long term use, we can end up with bone fractures. Nursing care includes closely monitoring the patient for diarrhea, cramping, and bloody stools. And then my way of remembering these drugs, if you look at how they're spelled, they both have that P-R-A-Z in the middle, so praise. It's not pronounced that way. It's pronounced omeprazole, but it kind of looks like oma-praise-all. So my son's little tip for how to remember this is, I want to praise you for taking your anti-ulcer medications. So if you like that tip, be sure to leave him a comment here because he was just accusing me of not giving him credit for his tricks that he gives me. So I definitely want to give him credit, and I have given him credit in the past, so leave him a comment. Thank you so much.

Sucralfate is the next medication I want to cover, which is a mucosal protectant that is used in the treatment of duodenal ulcers. So sucralfate reacts with the stomach's acid to form a thick paste which adheres to the ulcers. Key side effect with sucralfate is constipation. You want to administer this medication one hour before meals and at bedtime, so four times a day. Also, you want to encourage your patient to increase their intake of fiber and fluids because of that side effect of constipation. So my way of remembering this medication and what it's for, and the cool chicken hint here on the card, is sucralfate gets sucked down into ulcers. So S-U-C, sucralfate becomes sucked down into ulcers, which is pretty much what it does. So hopefully that's helpful for you.

Next, we have antacids, including aluminum hydroxide. Antacids are used to treat peptic ulcer disease as well as GERD. They work by neutralizing the stomach acid, and a key side effect of antacids is constipation. In terms of administration, we're going to give antacids after meals and at bedtime. So A for antacids and A for after meals. Another important thing to know about administration is that we never want to give antacids at the same time as other medications, so we want to give antacids one to two hours before or after other medications. So antacids are a little fussy when it comes to administration, because we need to give it after each meal and at bedtime, and we need to make sure we're not giving it with other medications.

The last medication I want to cover in this video is misoprostol, which is a prostaglandiin that is used to prevent gastric ulcers in patients taking NSAIDs. It also induces labor by ripening the cervix. So the mode of action of misoprostol is that it decreases stomach acid secretion, and it increases the production of protective mucus in the stomach as well as bicarbonate. And it also causes uterine contractions when used for labor induction. So side effects include dysmenorrhea as well as GI upset.

This medication does carry a black box warning because it can cause a miscarriage, premature birth and birth defects. So any time we are administering misoprostol for ulcer prevention in a female of childbearing age, we always want to run a pregnancy test first because it can cause a miscarriage. So my cool chicken hint here on this card, if you look at misoprostol, it kind of looks like me-so-prostol. So when you're pregnant, miso soup is okay; misoprostol is not. And again, it's pronounced misoprostol, but it looks like that miso. So I hope that hint was helpful for you.

Okay, time for quiz. I have three questions for you. First question. When should your patient take sucralfate? The answer is one hour before meals and at bedtime. Question number two. Aluminum hydroxide should be administered at the same time as other medications. True or false? The answer is false. So aluminum hydroxide is an antacid, and antacids should never be given at the same time as other medications. You need to give them one to two hours before or after other medications. Question number three. What nursing assessment should be done prior to administration of misoprostol? The answer is, you should run a pregnancy test for any woman of childbearing age who is prescribed misoprostol for ulcer prevention because this medication can cause a miscarriage.

Okay. I hope these quiz questions have been helpful. Hope the video was helpful. And hopefully my little silly ways of remembering these medications were also helpful. If you have other mnemonics or suggestions for how to remember these meds, definitely leave a comment so that everyone can benefit from your ideas as well. Thank you so much for watching.


Leave a comment

Comments will be approved before showing up.


Related Posts

Pharm, part 49: Immune Medications - TB, Systemic Antifungal, and Antiviral

Pharm, part 49: Immune Medications - TB, Systemic Antifungal, and Antiviral

Sep 25, 2021 0 min read

Tuberculosis (TB) medications (rifampin, isoniazid, pyrazinamide, ethambutol), systemic antifungal agents (amphotericin B, ketoconazole, fluconazole), and antivirals (acyclovir, ganciclovir, oseltamivir, zanamivir).
Read Article
Pharm, part 48: Immune Medications - Antibiotics - Others

Pharm, part 48: Immune Medications - Antibiotics - Others

Sep 25, 2021 0 min read

The following antibiotics: fluoroquinolones (ciprofloxacin, levofloxacin), sulfonamides (trimethoprim/sulfamethoxaole), urinary tract antiseptic (nitrofurantoin), and antiprotozoal (metronidazole).
Read Article
Pharm, part 47: Immune Medications - Antibiotics - Cell Wall Inhibitors

Pharm, part 47: Immune Medications - Antibiotics - Cell Wall Inhibitors

Sep 25, 2021 0 min read

Antibiotics that inhibit the bacterial cell wall, including: vancomycin, penicillins (penicillin G, amoxicillin, piperacillin/tazobactam), cephalosporins (cephalexin, ceftriaxone, ceftazidime, cefepime), and carbopenems (imipenem/cilastatin).
Read Article