Evaluation of Esophageal Transit of Tablets and Capsules in 30 Cats

Abstract

We have reported tablet-induced focal esophagitis and esophageal stricture formation in cats. The proposed mechanism is thought to be abnormal esophageal tablet retention resulting in focal esophagitis with subsequent stricture formation. The objective of this study was to evaluate the passage of tablets and capsules when given alone (dry swallow) and when followed by a water bolus (wet swallow) to determine if this could, in part, explain the esophageal stricture formation we have observed in cats. Fluoroscopy was used to evaluate tablet or capsule passage after administration. The percentage of dry tablet swallows that successfully passed into the stomach was 0.0% at 30 and 60 seconds, 6.7% at 90 seconds, 13.3% at 120 seconds, 26.7% at 180 and 240 seconds, and 36.7% at 300 seconds. Wet tablet swallows successfully passed 90.0% of the time at 30 seconds, 93.3% of the time at 60 seconds, and 100.0% of the time thereafter. The percentage of dry capsule swallows that successfully passed was 16.7% at each time interval. Wet capsule swallows successfully passed 96.7% of the time at 30 seconds and 100% of the time thereafter. For each time interval, wet swallows achieved significantly greater percentage passage into the stomach when compared to dry swallows (P Ͻ .05). This study shows that tablets or capsules given by dry swallow have prolonged retention in the esophagus compared to those given by wet swallow. On the basis of this study, we recommend the routine administration of a water bolus to cats receiving tablets or capsules PO to facilitate esophageal clearance. This practice may help prevent medication-associated esophagitis or stricture formation.

The pharmacokinetics of pimobendan enantiomers after oral and intravenous administration of racemate pimobendan formulations in healthy dogs

“…In addition to more rapid drug absorption, a liquid formulation of pimobendan may have advantages over capsule or tablet formulations, such as easier administration in some dogs, more accurate dosing by body weight, avoidance of lodging of the product in the oesophagus delaying passage into the stomach (Westfall et al ., ) and reduced cost of manufacture (Allen et al ., ). These may make an orally administered solution of pimobendan an attractive alternative.…”

Treatment of Ionized Hypercalcemia in 12 Cats (2006–2008) Using PO‐Administered Alendronate

“…Dosing recommendations given to owners were to follow administration of alendronate with administration of 6‐mL tap water8 PO by syringe and then application of a small amount of butter9 on the nasal planum to facilitate passage of the pill down the esophagus and into the stomach in as short a time as possible. These precautions are taken to minimize the risk of esophageal erosion or ulceration and subsequent strictures that have been described in humans taking alendronate for osteoporosis 21.…”

“…Four cats were started at 5 mg PO q7d as a consequence of their lower body weight. Owners were instructed to follow pill administration with 6 mL of tap water8 by syringe and a small amount of butter9 placed on the cat's nasal planum to increase salivation and shorten esophageal transit time.…”

Drug compounding for veterinary patients

“…Wet capsules passed 97% of the time at 30 seconds and 100% of the time thereafter. 8 The location of the entrapment of capsules is particularly disturbing because some medications given to cats such as doxycycline, tetracycline, propranolol, iron supplements, and bromide are known to cause esophageal lesions in experimental cats. 9,10 Because many drugs are not in a form that is ideal for the species being treated (eg, cats, exotic animals, pet birds), the tablets have been crushed, capsules reformulated, and solutions altered to make a more convenient and palatable oral dosage form.…”