Comparative pharmacokinetics of doxycycline in cats and dogs

Abstract

The disposition of doxycycline hyclate was studied in six adult mixed-breed female cats and six adult mid-sized female dogs following a single intravenous administration of 5 mg/kg body weight. Doxycycline volume of the central compartment, area volume of distribution, volume of distribution at steady state, and total body clearance were significantly smaller in cats. The differences were attributed to more extensive binding of doxycycline to plasma protein including albumin in cats. The significant differences in the volume of distribution and total body clearance were not reflected in elimination half-lives under the conditions of this study (sample size, inhomogeneous population). Doxycycline elimination half-life was 4.56 +/- 0.68 (SEM) h for cats and 6.99 +/- 1.09 h for dogs. Dosage regimens recommended in the veterinary literature were evaluated by the computer program PETDR.

Pharmacodynamics of Doxycycline and Tetracycline against Staphylococcus pseudintermedius: Proposal of Canine-Specific Breakpoints for Doxycycline

“…The pharmacokinetics of doxycycline in dogs have been assessed in previously published studies on the oral administration of doxycycline (10,11), the findings of a conference presentation (A. Dominguez, B. Kukanich, and K. Kukanich, presented at the American Academy of Veterinary Pharmacology and Therapeutics 18th Biennial Symposium, Potomac, MD, 20 to 23 May 2013), and one unpublished study performed by one of the veterinary drug sponsors (S. T. B. Rogar, unpublished data). Other studies of nonoral administration in dogs have been published for comparison with studies of oral administration and determination of protein binding (12)(13)(14)(15)(16)(17). The oral administration studies used for this analysis used a validated assay and uniform methods.…”

“…AUC/MIC calculations were performed using the following equation: AUC/MIC ϭ (f u · F · 24 h · dose)/(CL · MIC), where f u is the fraction unbound (protein unbound), F is the fraction absorbed, and CL is the systemic clearance. The value for f u used in the analysis was 0.084, because protein binding levels of 91.75% Ϯ 0.63% (12) and 91.4% (17) have been reported for dogs. Other parameters in the equation have been defined previously.…”

Farmacocinética y efectos adversos de la doxiciclina en el tratamiento de la Ehrlichiosis: fundamentos teóricos para ensayos clínicos en caninos

“…Debido a su mayor liposolubilidad en comparación con otras tetraciclinas, la doxiciclina posee un mayor volumen de distribución que le permite una mejor penetración en los tejidos a pesar de su alto porcentaje de unión a las proteínas plasmáticas (80% -90%) (3)(4)(5). Este antibiótico se emplea en el tratamiento de múltiples infecciones caninas, incluidas las causadas por Ehrlichia canis, donde se recomienda un régimen por un periodo de 28 días (4-6).…”

“…Doxycycline is a bacteriostatic antibiotic member of the tetracycline family that has been used in systemic pathways in human medicine and domestic animals for over 40 years (1)(2)(3). Due to its higher liposolubility compared to other tetracyclines, doxycycline has a greater distribution volume, which allows for better tissue penetration, despite its high binding percentage to plasma proteins (80% -90%) (3)(4)(5).…”

“…Due to its higher liposolubility compared to other tetracyclines, doxycycline has a greater distribution volume, which allows for better tissue penetration, despite its high binding percentage to plasma proteins (80% -90%) (3)(4)(5). This antibiotic is used in the treatment of multiple canine infections, including those caused by Ehrlichia canis, where the regime is recommended for a period of 28 days (4)(5)(6).…”