Pharmacokinetic studies of theophylline in dogs

Abstract

The pharmacokinetics of theophylline were investigated in dogs following intravenous, single oral, and multiple oral doses of aminophylline. Mean half-life (t1/2) of theophylline following single intravenous administration was 5.7 h and the apparent specific volume of distribution (V'd area) was 0.82 litre/kg. The bioavailability of theophylline was high (91%) following oral administration of aminophylline tablets and the absorption half-life (t1/2ab) was 0.4 h. Theophylline plasma concentrations observed following repeated oral administration of aminophylline tablets were somewhat greater than predicted. This suggests that theophylline plasma concentrations should be monitored and the dosage regimen individually adjusted in critically ill animals.

Chronic Bronchitis in Dogs

“…16 Although the pharmacokinetics of theophylline in the dog are well established, 17 only anecdotal reports address the occasional effectiveness of this drug for dogs with chronic bronchitis. 16 Although the pharmacokinetics of theophylline in the dog are well established, 17 only anecdotal reports address the occasional effectiveness of this drug for dogs with chronic bronchitis.…”

Pharmacokinetics of a modified, compounded theophylline product in dogs

“…Two oral formulations of theophylline exist: rapid release and extended release; specific products of both have been previously evaluated in dogs. Prior studies have shown excellent oral bioavailability of theophylline (>91%) (McKiernan, Neff‐Davis, Koritz, Davis, & Pheris, ; Tse & Szeto, ) as well as low plasma protein binding (Munsiff, Koritz, McKiernan, & Neff‐Davis, ). Evaluation of an oral, rapid release formulation of aminophylline (the ethylenediamine salt of theophylline) demonstrated a short half‐life.…”

The pharmacokinetics of a slow-release theophylline preparation in horses after intravenous and oral administration

“…Errecalde et al, 1984;Ingvast Larson et al, 1985McKiernan et aL, 1981McKiernan et al, 1983Rail, 1980Davis et al, 1987Koritz et aL, 1981 A longer half-life is one of the goals in designing a slow-release formulation. This has not been accomplished in this case.…”

“…It has also been indicated as a treatment for respiratory conditions in domestic animals (Davis, 1980;McKiernan et al, 1981;Koritz et al, 1986). This drug is a methylxanthine derivative, a phosphodiesterase inhibitor (Ziment, 1978), and has been used in horses suffering from chronic obstructive pulmonary disease (COPD) (Beech, 1979;Thomson and McPherson, 1983).…”