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Content Update

September 14, 2022

FDA Approval of Two Voquezna™ Products for Treatment of Helicobacter pylori Infection: In May 2022, the U.S. Food and Drug Administration (FDA) approved Voquezna™ Dual Pak™ (vonoprazan, amoxicillin) and Voquezna™ Triple Pak™ (vonoprazan, amoxicillin, clarithromycin) for treatment of H. pylori infection in adults. Vonoprazan™ is the first potassium-competitive acid blocker approved in the U.S.; it reversibly binds to potassium ions and blocks the hydrogen-potassium-ATPase enzyme system, thus preventing gastric acid secretion in a competitive potassium manner. In a randomized, multicenter, phase 3 clinical trial, vonoprazan triple therapy and dual therapy demonstrated noninferiority in H. pylori eradication rates compared to lansoprazole triple therapy.



Upon completion of the chapter, the reader will be able to:

  1. Describe the epidemiology and clinical presentation of commonly encountered gastrointestinal (GI) infections.

  2. Summarize common risk factors associated with the development of a GI infection.

  3. Given a patient with a GI infection, develop an individualized treatment plan.

  4. Outline the impact of widespread antimicrobial resistance on current treatment recommendations for GI infections.

  5. Discuss the effect of host immunosuppression on the risk of disease complications and treatment strategies associated with GI infections.

  6. Educate patients on appropriate prevention measures of GI infections, including vaccinations.


With suggested prevalence approaching one episode per person per year in resource-rich settings, and greater prevalence in low- and middle-income countries, most readers will have personal experience with gastrointestinal (GI) infections.1 Culprits in GI infections comprise a diverse group of microorganisms, including bacteria, viruses, and protozoans. Corresponding clinical presentations are also nuanced, but acute diarrheal illness is a common unifying theme. Syndromes of acute diarrhea or vomiting are described by the overarching term, gastroenteritis. Diarrhea, in turn, is most commonly defined as greater than three loose stools in a 24-hour period.

A useful way to broadly classify GI infections is to divide them into inflammatory or noninflammatory categories. Inflammatory diarrhea is caused by invasive or cytotoxin-producing bacteria, or in some cases by amoebae (eg, Entamoeba histolytica), which damage the intestinal mucosa. Characteristics of GI infections caused by these organisms include frequent, painful, small-volume bowel movements containing blood and mucus. Fever is another common, though not universal, symptom. Syndromes of inflammatory diarrhea are also frequently referred to as dysentery. Pathogens implicated in inflammatory GI infections are listed in Table 80–1.

Table 80–1Gastrointestinal Pathogens Causing Acute Diarrhea

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