Evaluation of the effect of a famotidine continuous rate infusion on intragastric pH in healthy dogs

Therapies in Exotic Animal Gastroenterology

This article reviews treatment of gastrointestinal (GI) disorders in exotic companion mammal species, birds, reptiles, amphibians, and fish. Treatment of GI stasis involves fluids, nutrition, and analgesia; there is minimal evidence suggesting prokinetics are useful. Research has evaluated the efficacy of various appetite stimulants in several exotic animal species. Although rabbits and rodents cannot vomit, maropitant may be beneficial by providing visceral analgesia. Gastroprotectants may be indicated for patients at risk for GI ulceration, such as anorexic psittacine birds. Immunosuppressives may be indicated for GI neoplasia and inflammatory bowel disease.

Rational use of gastroprotectants in cats: An evidence-based approach

PRACTICAL RELEVANCE

Acid-related disorders including esophagitis and gastroduodenal ulceration are uncommon in the cat. However, when they occur, they can have devastating consequences and require targeted intervention, including the use of gastroprotectants. Careful consideration of the causes of esophagitis and gastroduodenal ulceration can help the clinician to determine which gastroprotectant to use, and when to begin and end gastroprotective therapy.

CLINICAL CHALLENGES

Gastroprotectants remain one of the most misused classes of drugs in veterinary and human medicine. There are very few studies evaluating the efficacy of gastroprotective agents in cats. Furthermore, goals for the degree of gastric acid suppression are extrapolated from studies performed in dogs and humans.

AIMS

This review provides a foundation for the logical approach to the choice of gastroprotectant as indicated by the disease process, and is aimed at all veterinarians who prescribe gastroprotectants for use in cats.

EVIDENCE BASE

The guidance provided in this review is supported by current literature, including consensus opinion from the American College of Veterinary Internal Medicine. Gaps in evidence for use of gastroprotectants in cats are filled by extrapolations from studies performed in dogs and humans.

Targeting of KOR by famotidine promotes OPC maturation differentiation and CNS remyelination via STAT3 signaling pathway

This study aims to identify FDA-approved drugs that can target the kappa-opioid receptor (KOR) for the treatment of demyelinating diseases. Demyelinating diseases are characterized by myelin sheath destruction or formation that results in severe neurological dysfunction. Remission of this disease is largely dependent on the differentiation of oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes (OLGs) in demyelinating lesions. KOR is an important regulatory protein and drug target for the treatment of demyelinating diseases. However, no drug targeting KOR has been developed due to the long clinical trials for drug discovery. Here, a structure-based virtual screening was applied to identify drugs targeting KOR among 1843 drugs of FDA-approved drug libraries, and famotidine was screen out by its high affinity cooperation with KOR as well as the clinical safety. We discovered that famotidine directly promoted OPC maturation and remyelination using the complementary in vitro and in vivo models. Administration of famotidine was not only effectively enhanced CNS myelinogenesis, but also promoted remyelination. Mechanically speaking, famotidine promoted myelinogenesis or remyelination through KOR/STAT3 signaling pathway. In general, our study provided evidence of new clinical applicability of famotidine for the treatment of demyelinating diseases for which there is currently no effective therapy.

Gastroprotective Therapy

A range of gastroprotective drugs are available for the treatment of esophagitis and gastroduodenal mucosal injury including acid suppressants (ie, histamine-2 receptor antagonists, proton pump inhibitors), coating agents, prostaglandin analogs, and antacids. Of these, the proton pump inhibitors are the most effective drugs for the medical treatment of upper gastrointestinal injury. However, proton pump inhibitors are not effective for all causes of upper gastrointestinal injury. The choice of gastroprotective drug should be guided by the cause and location of gastrointestinal injury and the potential for adverse effects.

Comparative analysis of the effect of IV administered acid suppressants on gastric pH in dogs

Background

Upper gastrointestinal (GI) ulceration and bleeding in critically ill dogs can cause severe anemia and increase morbidity. Acid suppressants using proton pump inhibitors or histamine‐2 receptor blockers administered IV is commonly recommended.

Hypothesis/Objectives

To evaluate the efficacy of IV administered esomeprazole, pantoprazole, and famotidine constant rate infusion (CRI) on increasing the intragastric pH of dogs. We hypothesized that esomeprazole and famotidine CRI would provide superior acid suppression compared to pantoprazole and reach pH goals for the treatment of GI bleeding.

Animals

Nine healthy research Beagles.

Methods

Randomized, 3‐way crossover. Dogs received pantoprazole or esomeprazole at 1 mg/kg IV q12h and famotidine with a loading dose of 1 mg/kg followed by 8 mg/kg IV CRI daily for 3 consecutive days. The intragastric pH was recorded at baseline and for 72 hours of treatment. The mean pH and the mean percentage time (MPT) the intragastric pH was ≥3 or ≥4 were compared among and within treatment groups.

Results

Significant increases in mean pH (P < 0.0001), MPT ≥3 (P < 0.001), and MPT ≥4 (P = 0.0006) were noted over time with all 3 treatments. The time effect did not differ by treatment for mean pH, MPT ≥3, and MPT ≥4 (P = .29, .56, and .37, respectively); however, only esomeprazole and famotidine CRI achieved the goals established for the treatment of gastroduodenal ulceration in people.

Conclusions and Clinical Importance

Famotidine CRI and esomeprazole might be superior acid suppressants compared to standard doses of pantoprazole for the first 72 hours of treatment.

Evaluation of the effect of a famotidine continuous rate infusion on intragastric pH in healthy dogs

Background

Famotidine is sometimes administered as a continuous rate infusion (CRI) to treat gastrointestinal ulceration in critically ill dogs. However, clinical studies have not evaluated the efficacy of a famotidine CRI in dogs.

Hypothesis/Objectives

To evaluate the efficacy of famotidine at raising intragastric pH when it is administered as a CRI in dogs. We hypothesized that CRI treatment with famotidine would meet clinical goals for raising intragastric pH ≥3 and 4.

Animals

Nine healthy Beagle dogs.

Methods

Randomized 2‐way crossover. All dogs received 1.0 mg/kg IV q12h famotidine or CRI famotidine at 1.0 mg/kg IV loading dose and 8.0 mg/kg/d for 3 consecutive days. Beginning on day 0 of treatment, intragastric pH monitoring was used to continuously record intragastric pH. Mean percentage times (MPTs) for which intragastric pH was ≥3 and ≥4 were compared between groups using analysis of variance.

Results

There was a statistically significant difference (P < .05) in MPT ≥3 and ≥4 between the CRI and IV q12h groups on all treatment days. On days 1, 2, and 3, the MPTs ± SD for which pH was ≥3 were 92.1 ± 8.5, 96.3 ± 6.2, and 90.0 ± 15.7 for the CRI treatment group and 49.3 ± 27.3, 42.2 ± 19.6, and 45.8 ± 10.1, respectively, for the twice‐daily group.

Conclusions and Clinical Importance

These results suggest that a famotidine CRI, but not standard doses of famotidine, achieves the clinical goals established in people to promote healing of gastric tissue injury and offers an alternative to intravenous treatment with proton pump inhibitors in dogs.