Effect of feeding on the pharmacokinetics of oral minocycline in healthy adult horses

Abstract

Minocycline is commonly used to treat bacterial and rickettsial infections in adult horses but limited information exists regarding the impact of feeding on its oral bioavailability. This study's objective was to compare the pharmacokinetics of minocycline after administration of a single oral dose in horses with feed withheld and with feed provided at the time of drug administration. Six healthy adult horses were administered intravenous (2.2 mg/kg) and oral minocycline (4 mg/kg) with access to hay at the time of oral drug administration (fed) and with access to hay delayed for 2 hr after oral drug administration (fasted), with a 7-day washout between treatments. Plasma concentration versus time data was analyzed based on noncompartmental pharmacokinetics. Mean ± SD bioavailability (fasted: 38.6% ± 4.6; fed: 15.7% ± 2.3) and C max (fasted: 1.343 ± 0.418 μg/ml; fed: 0.281 ± 0.157 μg/ml) were greater in fasted horses compared to fed horses (p < .05 both). Median (range) T max (hr) in fasted horses was 2.0 (1.5-3.5) and in fed horses was 5.0 (1.0-8.0) and was not significantly different between groups. Overnight fasting and delaying feeding hay 2 hr after oral minocycline administration improve drug bioavailability and thus plasma concentrations.

Pharmacokinetics of single doses of maropitant citrate in adult horses

“…Oral F was low with high inter‐individual variability among horses (13.31 ± 5.30%), compared to dogs (23.7% [19.9%–28.3%]) and cats (50%) (Benchaoui et al., ; Hickman et al., ). This finding of reduced bioavailability of orally administered drugs in horses is common and has been found with numerous pharmaceuticals, including furosemide, tramadol, cephalexin, and minocycline (Davis, Salmon, & Papich, ; Echeverria, Lascola, Giguere, & Foreman, ; Johannson et al., ; Shilo et al., ). The reasons for this species difference are unknown.…”

Pharmacokinetics of minocycline in crucian carp (Carassius auratus ) after intravenous and oral administration

“…The pharmacokinetics of minocycline has been reported in some mammals, such as cats (Tynan, Papich, Kerl, & Cohn, ), dogs (Hnot, Cole, Lorch, Rajala‐Schultz, & Papich, ; Kukanich, Kukanich, Harris, & Heinrich, ), horses (Echeverria, Lascola, Giguere, & Foreman, ; Echeverria, Lascola, Giguere, Foreman, & Austin, ; Giguere, Burton, Berghaus, & Haspel, ; Schnabel et al., ), sheep (Wilson & Green, ), rabbits (Nicolau, Freeman, Nightingale, & Quintiliani, ) and humans (Zhou et al., ). However, so far there have been no pharmacokinetics reports in any fish species.…”

Pharmacokinetics study of oxyclozanide and levamisole hydrochloride compound suspension in sheep by LC-MS/MS

“…The reasons for the discrepancy in results between self-developed drug and other dosage forms may be related to different feeding practices [26,27], differences in animal species [28,29], parasite status in vivo [30], selectivity of analytical methods [31,32], or formulation preparation techniques [33]. The present study observed uctuation of drug concentrations in the plasma of levamisole hydrochloride in the body around 2h after administration in some sheep, and the emergence is most likely related to individual differences in the test animals, as well as the ruminant rumination situation and or stress during the test.…”