Characteristics of Acetaminophen Absorption in Healthy Unweaned Calves as an Indirect Measurement of the Oroduodenal Transit Rate of Liquid Meals

Abstract

Abomasal emptying plays an important role in the incidence of digestive problems in calves. Our aim was to evaluate the acetaminophen absorption test (APAT) for characterization of the oroduodenal transit (ODT) of liquid meals in unweaned calves. Six healthy, unweaned Simmental x Red Holstein crossbred calves were involved in the project. The study was performed in three blocks at 3, 6 and 9 weeks of the calves' age. Within blocks, APAT was performed twice at an interval of at least 24 h. Once per each block, liquid transit was carried out with non-coagulating electrolyte solution (NES). The second test within a block was performed either while atropine sulphate was administered (block I), or by feeding a coagulating milk replacer (block II), or by administration of NES by ruminal tube (block III). Data were compared within and among blocks. Significant differences of several APAT traits were present for the different types of feeding, the different types of meals, the administration of atropine sulphate and the different ages of the calves. The emptying index T(max)/C(max) was suggested to be a valuable kinetic parameter for the characterization of ODT in these calves. We conclude that APAT represents a valid technique for characterization of ODT of liquid meals in healthy unweaned calves and may be a valuable tool for the evaluation of the reticular groove mechanism, the abomasal emptying and the absorption capacity of the duodenum.

Pharmacokinetics of oral meloxicam in ruminant and preruminant calves

“…Although pH in the rumen may range from approximately 5.5–7.0, it is likely that little absorption of meloxicam occurs in that compartment, with the rumen serving mostly as a reservoir for extended release of drug into the remaining gastrointestinal tract. In studies of acetaminophen, which is unionized at physiological pH, an insignificant amount of the drug was absorbed from the rumen (Schaer et al. , 2005).…”

“…In calves, past studies with ampicillin, penicillin, tetracycline, chloramphenicol, trimethoprim, and acetominophen showed lower bioavailability when fed suspended in milk replacer compared with water (Nouws, 1992;Schaer et al, 2005). Proposed mechanisms included chelation with calcium and ⁄ or binding to milk proteins.…”

Effect of Erythromycin and Gentamicin on Abomasal Emptying Rate in Suckling Calves

“…Abomasal emptying was measured by acetaminophen absorption and glucose absorption. Acetaminophen is a widely used oral analgesic and antipyretic drug in humans, and its absorption provides an accurate method of determining the emptying rate of liquid phase meals in calves 22,23 . When administered PO, acetaminophen is absorbed in the small intestine 24 with the rate limiting step for absorption being the rate of gastric emptying in animals with normal small intestinal function 25 .…”

“…Acetaminophen is a widely used oral analgesic and antipyretic drug in humans, and its absorption provides an accurate method of determining the emptying rate of liquid phase meals in calves. 22,23 When administered PO, acetaminophen is absorbed in the small intestine 24 with the rate limiting step for absorption being the rate of gastric emptying in animals with normal small intestinal function. 25 Because the apparent rate of absorption is much faster than the rate of elimination in suckling calves, 22 the time to maximal acetaminophen concentration after oral ingestion is primarily dependent on the rate of abomasal emptying.…”

Evaluation of a modified acetaminophen absorption test to estimate the abomasal emptying rate in Holstein-Friesian heifers

“…With the exception of the d-xylose test, these proce-Evaluation of a modified acetaminophen absorption test to estimate the abomasal emptying rate in Holstein-Friesian heifers APAT Acetaminophen absorption test AUC Area under the plasma concentration-time curve AUC acet Area under the plasma acetaminophen concentration-time curve C max Maximum plasma acetaminophen concentration C maxmodel Maximum plasma acetaminophen concentration in a pharmacokinetic model T max Time to maximum plasma acetaminophen concentration T maxmodel Time to maximum plasma acetaminophen concentration in a pharmacokinetic model a dose of 1 mL/kg, 5 which is likely to influence abomasal emptying rate. 8,16,18,19 In ruminants, the APAT has been used to evaluate the function of the reticular groove reflex in lambs 20 and calves 21 as well as to determine effects of some presumably prokinetic drugs on abomasal emptying in suckling calves. 16,17 Therefore, in monogastric species and preruminating calves, the APAT, which involves measurement of plasma acetaminophen concentrations in short intervals after oral administration of an acetaminophen solution, is considered a reliable diagnostic tool to determine the gastric emptying rate.…”