Medical Management of Hemorrhagic Bowel Syndrome in a Beef Bull

Pharmacokinetics and pharmacodynamics of intravenously and subcutaneously administered pantoprazole in sheep (Ovis aries)

Abomasal ulcers are recognized in sheep of all ages, but research regarding therapeutic interventions is limited. Proton Pump Inhibitors (PPIs) such as pantoprazole, are clinically used with a paucity of evidence regarding efficacy in mature sheep. Intravenous and subcutaneously administered pantoprazole dosed at 1.0 mg/kg in adult sheep will increase the pH of abomasal fluid compared to pre-administration baseline. The objectives were to assess the effect of pantoprazole, after single and multiple administration, on abomasal fluid pH in adult sheep. A third objective was to describe the pharmacokinetic parameters of IV and SC pantoprazole. Four clinically healthy adult Southdown ewes previously fitted with a gastrostomy tube in the abomasum were utilized in this randomized, 2-way cross-over trial. Ewes received pantoprazole (1.0 mg/kg) as a single and 3-dose regimen (every 24 hours). After a 10 day washout period the reverse treatment was applied. Blood for analysis of pantoprazole concentration was collected intermittently for 24 hours, and abomasal fluid pH was measured at intervals for a 96-hour period. The pH of the abomasal fluid was higher in pantoprazole treatments for up to 24 hours after dosing. Following intravenous administration of pantoprazole to study ewes, elimination half-life, volume of distribution, and clearance of pantoprazole was estimated as 3.29 hours, 0.35 L/kg, and 65.26 mL/hr/kg respectively. After subcutaneous dosing, maximum concentration, time to maximum concentration, half-life of elimination, and volume of distribution, were estimated as 2604 ng/mL, 0.55 hours, 2.48 hours, and 0.37 L/kg. Additionally, the bioavailability was estimated as 83.33%. Pantoprazole administered IV or SC may be useful for treatment or prevention of abomasal ulcers in adult sheep.

The pharmacokinetics and pharmacodynamics of esomeprazole in sheep after intravenous dosing

Abomasal (gastric) ulceration is a morbidity in sheep, and currently, there is a paucity of pharmacokinetic and pharmacodynamic data for gastroprotectant drugs reported for this species. The proton pump inhibitor esomeprazole has been used in small animal and human patients for gastroprotection via increasing the gastric pH. The objective of this study was to report the pharmacokinetic parameters and pharmacodynamic effect of esomeprazole in sheep after single intravenous dosing. Four healthy adult Southdown cross ewes had blood collected over a 24  h time period after single intravenous dosing of esomeprazole at 1.0  mg/kg. Abomasal fluid was sampled over 24  h before and after esomeprazole administration. Plasma samples were analyzed for concentrations of esomeprazole and the esomeprazole metabolite, esomeprazole sulfone by high performance liquid chromatography. Pharmacokinetic and pharmacodynamic data were evaluated with specialized software. Esomeprazole was rapidly eliminated after IV administration. Elimination half-life, area under the curve, initial concentration (C0), and clearance were 0.2  h, 1,197  h*ng/mL, 4,321  ng/mL, and 0.83  mL/h/kg, respectively. For the sulfone metabolite elimination half-life, area under the curve and maximum concentration were 0.16  h, 22.5  h*ng/mL, and 65.0  ng/mL, respectively. Abomasal pH was significantly elevated from 1 to 6  h after administration and remained above 4.0 for at least 8 h after administration. No adverse effects were noted in these sheep. Esomeprazole was rapidly eliminated in sheep, similar to goats. Abomasal pH was increased, but future studies will be necessary to develop a clinical management approach to the use of esomeprazole in sheep.

Pharmacokinetic and pharmacodynamic properties of pantoprazole in calves

Introduction

Development of abomasal ulceration is a large concern, especially within calves; however, there is a paucity of research into the use of gastro protectants in ruminant species. Proton pump inhibitors, such as pantoprazole, are widely used in humans and companion animals. Their efficacy in ruminant species is undetermined. The objectives of this study were to 1) estimate the plasma pharmacokinetic parameters for pantoprazole in neonatal calves after three days of intravenous (IV) or subcutaneous (SC) administration, and 2) measure the effect pantoprazole had on abomasal pH over the treatment period.

Methods

Pantoprazole was administered to 6 Holstein-Angus cross bull calves at a dose of 1 mg/kg (IV) or 2 mg/kg (SC), once a day (every 24 h) for three days. Plasma samples were collected over a 72 h period and analyzed via HPLC-UV for determining pantoprazole concentrations. Pharmacokinetic parameters were derived via non-compartmental analysis. Abomasal (n= 8) samples were collected via abomasal cannulas over a 12 h period, per calf per day. Abomasal pH was determined via a bench top pH analyzer.

Results

Following Day 1 of IV administration, plasma clearance, elimination half-life, and volume of distribution of pantoprazole were estimated at 199.9 mL/kg/h, 1.44 h, and 0.51 L/kg, respectively. On Day 3 of IV administration, the reported values were 192.9 mL/kg/h, 2.52 h, and 1.80 L/kg mL, respectively. Elimination half-life and volume of distribution (V/F) of pantoprazole following SC administration were estimated at 1.81 h and 0.55 L/kg, respectively, on Day 1; and 2.99 h and 2.82 L/kg, respectively, on Day 3.

Discussion

The reported values for IV administration were similar to those previously reported in calves. SC administration appears to be well absorbed and tolerated. The sulfone metabolite was detectable for 36 h after the last administration for both routes. Abomasal pH was significantly higher than the pre-pantoprazole pH 4, 6, and 8 h after administration in both the IV and SC groups. Further studies of pantoprazole as a treatment/preventative for abomasal ulcers are warranted.

Pharmacokinetics of Pantoprazole and Pantoprazole Sulfone in Goats After Intravenous Administration: A Preliminary Report

Background: Ruminant species are at risk of developing abomasal ulceration, but there is a lack of pharmacokinetic data for anti-ulcer therapies, such as the proton pump inhibitor pantoprazole, in goats.

Objective: The primary study objective was to estimate the plasma pharmacokinetic parameters for pantoprazole in adult goats after intravenous administration. A secondary objective was to describe the pharmacokinetic parameters for the metabolite, pantoprazole sulfone, in goats.

Methods: Pantoprazole was administered intravenously to six adult goats at a dose of 1 mg/kg. Plasma samples were collected over 36h and analyzed via reverse phase high performance liquid chromatography for determination of pantoprazole and pantoprazole sulfone concentrations. Pharmacokinetic parameters were determined by non-compartmental analysis.

Results: Plasma clearance, elimination half-life, and volume of distribution of pantoprazole were estimated at 0.345 mL/kg/min, 0.7 h, and 0.9 L/kg, respectively following IV administration. The maximum concentration, elimination half-life and area under the curve of pantoprazole sulfone were estimated at 0.1 μg/mL, 0.8 h, and 0.2 hr^*μg/mL, respectively. The global extraction ratio was estimated 0.00795 ± 0.00138. All animals had normal physical examinations after conclusion of the study.

Conclusion: The reported plasma clearance for pantoprazole is lower than reported for foals, calves, and alpacas. The elimination half-life appears to be < that reported for foals and calves. Future pharmacodynamic studies are necessary for determination of the efficacy of pantoprazole on acid suppression in goats.

Retrospective study on the use of lidocaine constant rate infusions for the treatment of ileus in ruminants and camelids

Limited knowledge exists regarding the use of lidocaine as a prokinetic in ruminants and camelids to treat gastrointestinal ileus. In this retrospective study, ruminant and camelid cases diagnosed with ileus and treated with a lidocaine constant rate of infusion were assessed for adverse reactions and medical outcomes. A review of medical records was performed to identify cases in which lidocaine was administered as a prokinetic. Ten cases were identified consisting of 8 cattle, 1 goat, and 1 alpaca. Nine animals improved with a lidocaine treatment. No adverse effects were reported during lidocaine administration. Nine animals were discharged, and 1 was euthanized.

Pharmacokinetics and Tissue Levels of Pantoprazole in Neonatal Calves After Intravenous Administration

Background: Neonatal calves are at risk of developing abomasal ulceration, but there is a lack of pharmacokinetic data for potential anti-ulcerative therapies, such as pantoprazole, in ruminant species. Objective: The study objectives were to estimate plasma pharmacokinetic parameters for pantoprazole in neonatal dairy calves after intravenous (IV) administration. A secondary objective was to quantify the concentrations of pantoprazole in edible tissues after IV dosing. Methods: Pantoprazole was administered to 9 neonatal Holstein calves at a dose of 1 mg/kg IV. Plasma samples were collected over 24 h and analyzed via HPLC-MS for determining pantoprazole concentrations. Pharmacokinetic parameters were derived via non-compartmental analysis. Tissue samples were collected at 1, 3, and 5 days after administration and analyzed via HPLC-MS. Results: Following IV administration, plasma clearance, elimination half-life, and volume of distribution of pantoprazole were estimated at 4.46 mL/kg/min, 2.81 h, and 0.301 L/kg, respectively. The global extraction ratio was estimated at 0.053 ± 0.015. No pantoprazole was detected in the edible tissues 1, 3, or 5 days after administration. A metabolite, pantoprazole sulfone was detected in all the edible tissues 1 and 3 days after administration. Conclusion: The reported plasma clearance for pantoprazole is less than that reported for alpacas but higher than reported in foals. The elimination half-life in calves appears to be longer than observed in foals and alpacas. While pantoprazole sulfone was detected in the tissues after IV administration, further research is needed as to the metabolism and potential tissue accumulation of other pantoprazole metabolites in calves. Future pharmacodynamic studies are necessary to determine the efficacy of pantoprazole on abomasal acid suppression in calves.

A Retrospective Clinical Investigation of the Safety and Adverse Effects of Pantoprazole in Hospitalized Ruminants

Clinical safety data for the use of gastroprotectants in hospitalized ruminants is lacking. In human patients, multiple adverse effects are possible from the use of pantoprazole including hematologic and electrolyte abnormalities as well as anaphylaxis and edema. The medical records of all hospitalized cattle, goats, and sheep administered pantoprazole over an ~5-year period were retrospectively analyzed for adverse effects. Seventy-nine eligible patients were observed. Hypomagnesemia was observed after pantoprazole administration in 10 cattle; however, no significant changes were noted when compared to baseline before pantoprazole administration. Significant changes were noted in serum indicators of hepatic and renal function; however, these represented downward trends that were most likely clinically insignificant. Anaphylaxis after pantoprazole administration was not observed; however, seven cattle displayed edema after pantoprazole administration. Veterinary clinicians should be aware of the potential for hypomagnesemia in hospitalized ruminants being administered pantoprazole and monitor patients accordingly. While these preliminary retrospective results indicate that pantoprazole may be a safe adjunctive therapy in hospitalized ruminants, additional studies are necessary to further determine the safety and toxicity of pantoprazole in ruminants.