ACVIM consensus statement on GI protectants: What you need to know

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The American College of Veterinary Internal Medicine (ACVIM) recently released a consensus statement addressing concerns about excessive gastrointestinal (GI) protectant administration in dogs and cats. According to the statement, “Inappropriate prescription of acid suppressants is commonplace in veterinary medicine,” particularly during routine management of certain conditions such as pancreatitis and renal disease, so “judicious use … is warranted.”

Gastroprotectant drug options

The ACVIM statement includes consensus opinions detailing the use of various acid-suppressing drugs. None of these options are approved for use in dogs and cats, underscoring the need for continuous pharmaceutical research specifically in companion animal species.

Antacids

Typically composed of insoluble salts, antacids lack any systemic effects. Because of this, they are short-acting and not strong enough to increase gastric pH significantly. Therefore, they should be considered relatively ineffective treatments for gastroduodenual ulceration and erosion (GUE) or gastroesophageal reflux disease (GERD) compared with other drug options.

Histamine type 2 receptor antagonists (H2RAs)

The H2RAs, which include cimetidine, ranitidine and famotidine, inhibit gastric acid secretion by blocking receptors on the stomach's parietal cells. When administered once or twice a day, the ACVIM concludes, H2RAs offer inferior benefits compared with proton pump inhibitors (PPIs) for treatment of GUE and reflux esophagitis. Furthermore, combining an H2RA with a PPI may decrease efficacy of the PPI.

Proton pump inhibitors

PPIs, including omeprazole, pantoprazole, esomeprazole and lansoprazole, have a longer duration of action than either antacids or H2RAs, and maximum effect occurs about two to four days after administration. When administered twice daily, PPIs are the best option for treating GUE in dogs and cats; however, the ACVIM notes that long-term administration should be tapered. Diarrhea and intestinal dysbiosis are the most common adverse effects associated with PPI administration.

Because PPIs increase gastric lumen pH, their use may decrease the effectiveness of other drugs that need an acidic environment for maximum absorption. These include azole antifungal drugs, the immunosuppressive drug mycophenolate, iron and the platelet inhibitor clopidogrel.

Misoprostol

A synthetic prostaglandin E1 analog, misoprostol decreases the release of histamine, pentagastrin and meal-stimulated gastric acid. In one study, the drug significantly reduced, but did not eliminate, gastric damage in dogs treated with high-dose aspirin. However, it remains unknown whether misoprostol is an effective gastroprotectant against damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs), other than aspirin, or by glucocorticoids.

Sucralfate

Sucralfate is a complex salt that acts by forming stable complexes with proteins in damaged areas of the GI mucosa. The ACVIM consensus statement notes only “weak evidence” supporting the use of sucralfate for treating esophageal injury, and its analgesic properties in companion animal species are unknown. The drug is more effective when administered as a liquid suspension than intact tablets. Sucralfate should be considered an inferior treatment for GUE compared with a PPI, and the addition of sucralfate to H2RA or PPI therapy offers no additional benefit, according to the ACVIM.

When to use gastroprotectants

Gastroduodenal ulceration and erosion

GUE can result from several conditions, including neoplasia, inflammatory bowel disease and NSAID administration. According to the ACVIM, twice-daily therapy with a PPI is considered the best treatment of GUE in dogs and cats.

Stress-related mucosal damage due to high performance

Studies have documented an increased prevalence of gastric erosion, hemorrhage and ulcers in performance dogs and horses compared with animals with lower activity levels. The ACVIM states that prophylactic gastroprotectant administration may be warranted in high-performance individuals to decrease the risk of stress-related mucosal damage.

Renal disease

Unlike in humans, end-stage renal disease has no known association with gastritis or GUE development in dogs and cats, yet many patients are given prophylactic gastroprotectants. There is evidence in human patients, however, that this may decrease bone mineral density and cause pathologic fractures. Thus, acid suppression should be restricted to patients at high risk for GI ulceration or bleeding.

Reflux esophagitis

Studies in humans show that acid suppression may reduce the risk of esophagitis secondary to GERD. Although PPIs will not prevent gastric reflux in dogs and cats, they can increase reflux pH and, therefore, prevent injury.

Other conditions

The ACVIM does not recommend gastroprotectant use for patients in the intensive care unit or for the following indications, unless the patient is considered at high risk for GUE or other gastrointestinal damage:

Pancreatitis

Nonerosive gastritis

Renal disease

Thrombocytopenia-induced bleeding

Non–H pyloriHelicobacter infection

Hepatic disease without GI bleeding

Spinal cord injury

Take-home message

GI protectants are frequently overused in dogs and cats. Because current recommendations are based largely on results from studies in humans and healthy animals, the ACVIM stresses the need for focused studies in those patients at highest risk for GI bleeding or damage.

View the complete statement here.

Dr. Natalie Stilwell provides freelance medical writing and aquatic veterinary consulting services through her business, Seastar Communications and Consulting. In addition to her DVM obtained from Auburn University, she holds an MS in fisheries and aquatic sciences and a PhD in veterinary medical sciences from the University of Florida.