Gastrointestinal Disease: A Brief Review of Medication Therapies

Background

Controlling clinical signs is an important component of managing dogs and cats with GI disease. This review highlights several drug classes that are commonly used in these cases. 

Antiemetics

Maropitant and ondansetron are commonly prescribed antiemetic and antinausea agents. Although comparative studies have detected slight differences (maropitant may be a modestly more effective antiemetic; ondansetron appears somewhat more effective for nausea), both drugs are effective and superior to metoclopramide.^1-6 Acepromazine has antiemetic and antinausea effects.^7-10 First-generation antihistamines (eg, dimenhydrinate, meclizine) may be considered for motion sickness or vomiting caused by vestibular disease.

Appetite Stimulants

Capromorelin is approved as an appetite stimulant in dogs and for the management of weight loss in cats with chronic kidney disease.^19,20 Mirtazapine tablets have an extensive history of use as an appetite stimulant,^21-23 and a transdermal formulation is approved for use in cats.²⁴ Studies comparing the effectiveness of these agents have not been conducted. In cats, gabapentin increased food intake in the 6-hour period following ovariectomy surgery.²⁵ Cyproheptadine increases appetite in dogs and cats, and benzodiazepines (eg, oxazepam, diazepam) have been observed to improve appetite in cats, but adverse effects, including fatal idiosyncratic hepatic failure in cats administered oral diazepam, limit their use.²⁶

Acid Modifiers & GI Protectants

Decreasing gastric acid secretion is an essential component for treating several clinical GI diseases (eg, gastric or duodenal ulcers, reflux esophagitis). Proton-pump inhibitors (PPIs; eg, omeprazole, pantoprazole) are more effective acid-suppressing drugs than histamine-2 receptor antagonists (eg, famotidine).^27-29 When PPIs are administered to patients for >4 weeks, they should be gradually tapered to avoid rebound gastric acid hypersecretion.³⁰ Misoprostol may prevent gastroduodenal ulceration caused or aggravated by NSAIDs, but PPIs are usually better tolerated.^30-33 Sucralfate is commonly prescribed to prevent or treat oral, esophageal, gastric, and duodenal ulcers^34,35; however, evidence to support the drug’s effectiveness for these indications is limited.^30,36