The pharmacokinetics of a slow-release theophylline preparation in horses after intravenous and oral administration.
The pharmacokinetics of a slow-release theophylline formulation was investigated following intravenous and oral administration at 10 mg/kg in horses. A tricompartmental model was selected to describe the intravenous plasma profile. The elimination half-life (t1/2 beta) was 16.91 +/- 0.93 h, the apparent volume of distribution (Vd) was 1.35 +/- 0.18 L/kg and the body clearance (ClB) was 0.061 +/- 0.009 L kg-1 h. After oral administration the half-life of absorption was 1.24 +/- 0.30 h, and the calculated bioavailability was above 100%. The t1/2 beta after oral administration was 18.51 +/- 1.75 h, only a little longer than that after intravenous administration. The slow release formulation did not exhibit any advantage in prolonging the t1/2 beta of theophylline in the horse.
Errecalde
J O
JO
Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina.
Landoni
M F
MF
D000042:Absorption; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D003692:Delayed-Action Preparations; D005260:Female; D006207:Half-Life; D006736:Horses / Q000378:metabolism*; D007262:Infusions, Intravenous / Q000662:veterinary; D013806:Theophylline / Q000008:administration & dosage / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D003692:Delayed-Action Preparations; D013806:Theophylline