Effects of half-solid nutrients on gastroesophageal reflux in beagle dogs with or without cardioplasty and intrathoracic cardiopexy

Gastrointestinal transit time is faster in Beagle dogs compared to cats

OBJECTIVE

To characterize gastrointestinal transit times (GITTs) and pH in dogs, and to compare to data recently described for cats.

ANIMALS

7 healthy, colony-housed Beagles.

PROCEDURES

The GITTs and pH were measured using a continuous pH monitoring system. For the first period (prefeeding), food was withheld for 20 hours followed by pH capsule administration. Five hours after capsule administration, dogs were offered 75% of their historical daily caloric intake for 1 hour. For the second period (postfeeding), food was withheld for 24 hours. Dogs were allowed 1 hour to eat, followed by capsule administration. Both periods were repeated 3 times. The GITTs and pH were compared to published feline data.

RESULTS

The mean ± SD transit times in dogs for the pre- and postfeeding periods, respectively, were esophageal, 3 ± 5 minutes and 13 ± 37 minutes; gastric, 31 ± 60 minutes and 829 ± 249 minutes; and intestinal, 795 ± 444 minutes and 830 ± 368 minutes. The mean ± SD gastrointestinal pH in dogs for the pre- and postfeeding periods, respectively, were esophageal, 6.6 ± 0.6 and 5.7 ± 1.0; gastric, 3.0 ± 1.4 and 1.8 ± 0.3; intestinal, 7.9 ± 0.3 and 7.7 ± 0.6; first-hour small intestinal, 7.6 ± 0.5 and 7.1 ± 0.4; and last-hour large intestinal, 7.9 ± 0.6 and 7.7 ± 1.0. The first-hour small intestinal pH and total transit times varied between dogs and cats depending on feed period (P = .002 and P = .04, respectively). Post hoc analysis revealed significantly shorter total transit times in dogs prefeeding (P = .005; mean ± SD for cats, 2,441 ± 1,359 minutes; for dogs, 828 ± 439 minutes) and postfeeding (P = .03; mean ± SD for cats, 3,009 ± 1,220 minutes; for dogs, 1,671 ± 513 minutes). Total transit time for dogs was also shorter pre- versus postfeeding (P = .003).

CLINICAL RELEVANCE

GITT is faster in Beagles compared to cats, but gastrointestinal pH are similar when fed the same diet.

Effects of concurrent and staggered dosing of semi-solid enteral nutrients on pharmacokinetic behavior of antiepileptic drugs after oral administration in rats

Background

The use of enteral nutrients plays a highly important role in accurate nutrition management, but limited information is currently available on the cautionary points of semi-solid enteral nutrients.

Aim

In this study, we examined whether the pharmacokinetic profiles of sodium valproate (SVA), levetiracetam (LEV), and carbamazepine (CBZ) are affected by altering the dosing time of RACOL^®-NF Semi Solid for Enteral Use (RASS), a prescribed semi-solid formula. We also investigated whether the pharmacokinetic interaction observed in this study can be avoided by staggered dosing of the chemical drug and semi-solid enteral nutrient.

Methods

The plasma concentration of SVA, LEV and CBZ after oral administration was measured by LC-MS/MS method.

Results

There was no difference in pharmacokinetic characteristics of SVA and LEV when the dosing time of RASS was altered. On the other hand, the plasma concentration of CBZ after oral administration at all sampling points decreased with the extension of the dosing time of RASS, which was consistent with the C_max and AUC. However, no significant difference was observed in the pharmacokinetic profiles or parameters of CBZ between the short-term and long-term RASS dosing groups by prolonging the administered interval of CBZ and RASS for 2 hr.

Conclusion

We concluded that the pharmacokinetic profiles of CBZ, but not SVA and LEV, after its oral administration are affected by the dosing time of RASS, but staggered administration of CBZ and RASS prevented their interaction.

Effects of semi-solidification of enteral nutrients on the pharmacokinetic behavior of orally administered carbamazepine in rats

The use of semi-solid enteral nutrients plays an extremely important role in accurate nutrition management. In the present study, we compared the pharmacokinetic profile of orally administered carbamazepine (CBZ) in rats treated with liquid RACOL^®, semi-solid RACOL^®, and HINE E-gel^®, which are enteral nutrients marketed in Japan. Since liquid and semi-solid formulations are both marketed in Japan for RACOL^®, liquid RACOL^® was orally administered to control rats. The serum concentration of CBZ at each sampling point was lower in the semi-solid RACOL^®-treated group than in the liquid RACOL^®-treated group. No significant differences were observed in the pharmacokinetic behavior of CBZ between the semi-solid RACOL^®-treated and HINE E-gel^®-treated groups. Regarding pharmacokinetic parameters, the impact of the area under the curve (AUC_0→5h) was the liquid RACOL^® group > the semi-solid RACOL^® group ≈ the HINE E-gel^® group. Therefore, we concluded that serum concentrations of CBZ were lower when concurrently treating with semi-solid enteral nutrients than when simultaneously processing liquid enteral nutrients.

In vitro and in vivo effects of selected fibers on the pharmacokinetics of orally administered carbamazepine: Possible interaction between therapeutic drugs and semisolid enteral nutrients

OBJECTIVE

The management of nutrition using semisolid enteral nutrients is considered useful for avoiding the adverse effects associated with liquid enteral nutrients. In the present study, we used an in vitro analysis to investigate whether carbamazepine (CBZ) is adsorbed by the fibers included in semisolid enteral nutrients. The effects of these fibers on the pharmacokinetic profile of CBZ following its oral administration were also examined in rats.

METHODS

The adsorption of CBZ onto fibers was examined by absorbance monitoring of the filtrate after centrifugation using an ultrafiltration device. Viscosities of each solution were measured by rotational viscosimeter. The CBZ concentration profile after its oral administration (50 mg/kg) was analyzed by a noncompartmental method.

RESULTS

In the two solutions used to reflect gastric juice and fluid in the intestinal tract, CBZ was more strongly adsorbed by water-soluble fibers (guar gum and xanthan gum) than by insoluble fibers (dextrin hydrate). The adsorption of CBZ also was observed even if the concentrations of guar gum and xanthan gum were reduced to such an extent that viscosity was 0 Pa･s. The pharmacokinetic examination of orally administered CBZ revealed that the area under the curve was significantly lower in the guar gum and xanthan gum groups than in the control group.

CONCLUSION

CBZ was adsorbed by fibers used for the semisolidification of enteral nutrients, which may be partially responsible for the alterations observed in the pharmacokinetic profile of CBZ.

Semi-solid feeds may reduce the risk of aspiration pneumonia and shorten postoperative length of stay after percutaneous endoscopic gastrostomy (PEG)

Background and study aims: Feeding-related adverse events after percutaneous endoscopic gastrostomy (PEG) such as aspiration pneumonia may result in prolonged hospitalization and postoperative mortality. This study evaluated the efficacy of using semi-solid feeds to reduce feeding-related adverse events and improve clinical outcomes. Patients and methods: Patients who received PEG for enteral nutrition at our hospital between January 2014 and December 2015 were allocated to a postoperative feeding protocol that used either liquid feed or semi-solid feed. Baseline characteristics, postoperative feeding-related adverse events and clinical outcomes in the 2 groups were prospectively analysed and compared. Results: One hundred and seventeen PEG patients (age range: 59 - 97 years, male: 53) were enrolled with 72 patients given liquid feed and 45 patients receiving semi-solid feed. Baseline characteristics were similar in both groups. The semi-solid feed group experienced fewer incidence of feeding-related aspiration pneumonia (2.2 % vs. 22.2 %, P < 0.005) and shorter postoperative hospital length of stay (12.7 days vs. 18.8 days, P < 0.01). Significant differences were not observed in the frequency of peristomal infection (11.1 % vs. 12.5 %, P = 0.82), feeding-related diarrhea (2.2 % vs. 12.5 %, P = 0.09) and 30-day mortality rates (2.2 % vs. 8.3 %, P = 0.25). Conclusions: Semi-solid feeding may reduce the risk of aspiration pneumonia and shorten postoperative hospital length of stay after PEG. Semi-solid feeds are safe to use and can be employed either as a first line feeding protocol or an alternative when liquid feeding is unsuccessful.

Ambulatory esophageal pHmetry in healthy dogs with and without the influence of general anesthesia

This research aimed to determine the value of esophageal pH in awake and anesthetized dogs, to evaluate the esophageal pH value in awake dogs, in different body positions, as well as to study the occurrence of gastroesophageal reflux episodes in these positions. Thus, 40 healthy male and female adult dogs with mean body weight of 15.5 ± 4.6 kg were used. Esophageal pHmetry was conducted by inserting a catheter through the oropharynx in 30 dogs (stage 1) anesthetized with acepromazine, propofol and isoflurane, submitted to elective ovariosalpingohysterectomy. In addition, 8-h esophageal pHmetry was carried out transnasally in 10 awake dogs (stage 2), allowed to move and change body positions (lateral and sternal decubitus, and standing position), which were recorded. The mean esophageal pH value was lower (p < 0.01) in the anesthetized dogs (7.3 ± 0.82) than in the awake dogs (8.2 ± 0.3). Only four anesthetized dogs (13.33%) suffered reflux episodes. Reflux was not observed in the awake dogs and no esophageal pH differences were found between the body positions studied. Compared to the alert state, general anesthesia in dogs submitted to the previously mentioned anesthesia protocol causes esophageal pH reduction and predisposes to the occurrence of gastroesophageal reflux episodes. Transnasal pHmetry of 8 h in healthy awake dogs reveals that the esophageal pH value is alkaline and does not vary according to body position. In these animals, decubitus position is not a determining factor for reflux episodes to occur.