Comparison of nuclear scintigraphy and acetaminophen absorption as a means of studying gastric emptying in horses

Abstract

Tmax and Ka are valuable variables in the assessment of liquid-phase gastric emptying using acetaminophen absorption. Acetaminophen absorption may be a valuable alternative to nuclear scintigraphy in the determination of gastric emptying rates in equine patients with normally functioning small intestine.

Determination of abomasal emptying rate in suckling calves by use of nuclear scintigraphy and acetaminophen absorption

“…In contrast, when serum acetaminophen concentrations were analyzed by use of fluorescence polarization immunoassay in samples obtained from horses administered acetaminophen at a rate of 20 mg/kg, a lower value was obtained for Cmax (16.7 µg/mL). 12 The Cmax value was 14 µg/mL in humans administered acetaminophen (14 mg/kg) when acetaminophen was assayed by use of high-performance liquid chromatography. 16 It is not clear whether the range of values for Cmax reflects differences in dose, analytic method, nature of test solutions, or emptying rate from the stomach.…”

“…Nuclear scintigraphy is widely regarded as the criterion-referenced method for assessing gastric emptying because it is accurate, quantitative, and sensitive. 12 Scintigraphy allows the calculation of emptying indices such as the half emptying time (t 1/2 ; the time required for 50% of the initially administered volume to be emptied from the stomach) and has become the standard technique for use in evaluating gastric emptying in humans and horses.…”

Effects of indwelling nasogastric intubation on gastric emptying of a liquid marker in horses

“…In the study reported here, different rate metrics to evaluate GER were considered. In 1 study, 8 values for C max and AUC at 240 minutes were not well correlated with the criterion-referenced standard of scintigraphic measurement, whereas in another study, 9 values for T max were in close agreement with scintigraphically obtained values for gastric emptying in horses with experimentally induced delay in gastric emptying and in healthy horses. It has also been reported 11 that determination of AUC at a given time point does not offer any advantage over determination of C max ; however, it is unknown whether the time up to which AUC is integrated has a different effect on the final result.…”

“…The rate-limiting step for absorption of acetaminophen is gastric emptying. 4 The use of acetaminophen for the measurement of liquid GER in horses and ponies has been validated, 9 although the optimal metric rate to use for determination of acetaminophen as a marker of GER is currently under debate.…”

Effect of tulathromycin on abomasal emptying rate in healthy lactating goats

“…Acetaminophen absorption pharmacokinetic values are widely used as an index of gastric emptying and have been validated against the gold standard method (scintigraphy) in humans (Clements et al, 1978), horses (Lohmann et al, 2000) and suckling calves (Marshall et al, 2005). The main advantages of the acetaminophen absorption technique are its low cost, wide availability, and ease of assay (Clements et al, 1978).…”