The effect of surgery (Ovariohysterectomy) on the plasma disposition of meloxicam following intravenous administration in dogs

The aim of this study was to determine the changes in the pharmacokinetics of meloxicam in goat kids who were castrated following the administration of xylazine. Six goat kids were used for the study. The study was performed in two periods according to a longitudinal study, with a 15‐day washout period between periods. In the first period (Control group), 1 mg/kg meloxicam was administered by i.v. route to kids. In the second period (Castration group), the kids were sedated with 0.3 mg/kg xylazine and castration was performed following meloxicam administration. Plasma meloxicam concentration was analyzed using HPLC‐UV, and pharmacokinetic parameters were calculated by noncompartmental model. In the control group following the administration of meloxicam, mean elimination half‐life (t1/2ʎz), area under the concentration–time curve (AUC0−∞), total body clearance (ClT), and volume of distribution at steady‐state (Vdss) were 13.50 ± 0.62 hr, 41.10 ± 2.86 hr µg/ml, 24.43 ± 1.75 ml hr−1 kg−1, and 0.45 ± 0.03 L/kg, respectively. In the castration group, the t1/2ʎz of meloxicam prolonged, AUC0−∞ increased, and ClT and Vdss decreased. In conclusion, the excretion of meloxicam from the body slowed and the t1/2ʎz was prolonged in the castrated goat kids following xylazine administration. However, there is a need to determine the pharmacodynamics of meloxicam in castrated goat kids.

Section: Discussionsupporting

confidence: 87%

“…The decrease in V dss may be due to the hemodynamic effects of xylazine or alteration in the binding of meloxicam to plasma proteins. Moreover, V dss of meloxicam is reportedly decreased in dogs undergoing ovariohysterectomy (Karademir, Aksit, et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Effect of castration procedure on the pharmacokinetics of meloxicam in goat kids

Tekeli

Türk

Çorum

et al. 2020

“…Clearance is directly proportional to the blood flow (Toutain & Bousquet‐Mélou, ): during general anaesthesia with isoflurane, a reduction of the cardiac output can occur (Avram et al., ), and this could have been responsible for the lower clearance. A lower clearance of meloxicam was also observed in dogs undergoing surgery under general anaesthesia compared to conscious dogs (Karademir et al., ). In our study, meloxicam was administered approximately 30 min before the end of surgery and, consequently, the effect of the general anaesthesia on the cardiac output and blood flow was present for a shorter time compared to the study of Little et al.…”

Section: Discussionmentioning

confidence: 91%

Postoperative pharmacokinetics of meloxicam in horses after surgery for colic syndrome

Salvo

Giorgi

Nannarone

et al. 2017

NSAIDs are often used in horses with colic syndrome during the postoperative period, due to their ability to contrast endotoxemia and to promote an analgesic and anti-inflammatory effect. As the pharmacokinetics of a drug are often modified in unhealthy animals compared to healthy subjects, the aim of this study was to evaluate the pharmacokinetic profile of meloxicam after i.v. administration in horses undergoing laparotomy for colic syndrome. Eight horses received 0.6 mg/kg of meloxicam i.v. towards the end of surgery. Blood samples were taken at scheduled time points during the following 24 hr. The serum concentration of the drug was determined by HPLC. Terminal half-life (6.88 ± 2.96 hr), volume of distribution at steady-state (186.53 ± 61.20 ml/Kg) and clearance (27.91 ± 5.72 ml kg hr ) were similar to those reported in literature for healthy horses. This result suggests that no adjustment of the approved dose should be necessary when meloxicam is used to treat horses in the immediate postoperative period after surgery for colic syndrome.

“…The elimination half‐life of meloxicam in dogs (12.7 h) extended well beyond the duration of the anaesthesia (29 min surgery) in Karademir et al. (2016). Hence, robenacoxib in cats is a better comparator to meloxicam in birds because (a) most of the drug was eliminated in the perioperative period and a lesser proportion during recovery and (b) protein binding is equally high (unknown for meloxicam in birds but 97% in dogs and cats, and > 98% for robenacoxib in cats).…”

Section: Discussionmentioning

confidence: 66%

“…(2016) and Karademir et al. (2016) demonstrated, for two NSAIDs (robenacoxib in cats and meloxicam dogs, respectively), an effect of anaesthesia on volume of distribution but no significant effect on clearance. The elimination half‐life of meloxicam in dogs (12.7 h) extended well beyond the duration of the anaesthesia (29 min surgery) in Karademir et al.…”

Section: Discussionmentioning

confidence: 98%

Perioperative pharmacokinetics and pharmacodynamics of meloxicam in emus (Dromaius novaehollandiae) of different age groups using nonlinear mixed effect modelling

Castiñeiras

Armitage

Lamas

et al. 2020

Meloxicam is a widely used nonsteroidal anti‐inflammatory drug in avian species. However, variability in pharmacokinetic (PK) and pharmacodynamic (PD) parameters in birds warrants species‐specific studies for dose and dosing interval optimization. We performed a perioperative PK study of meloxicam (0.5 mg/kg, intravenously) on emus of three different age groups: 3 chicks (5 weeks old, 3.5 kg), 4 juveniles (26 weeks old, 18.8 kg) and 6 adults (66 weeks old, 38.8 kg). A two‐compartment population PK model including weight as a significant covariate on clearance and central volume of distribution (V1) best fitted the data. The typical values (20 kg bird) for clearance and V1 were 0.54 L/kg/h and 0.095 L/kg. Both parameters significantly decreased with increasing weight/age. Meloxicam potency and selectivity for COX‐1 and COX‐2 were measured in whole blood assays (TxB2 production endpoint). Meloxicam was partially selective in emus (IC50 COX‐1:COX‐2 = 9.1:1). At the current empirical dose (0.5 mg/kg/24 hr), plasma meloxicam concentration is above IC50 of COX‐2 for only 2 hr. PK/PD predicted dose required for 80% COX‐2 inhibition over 24 hr were 3.4, 1.4 and 0.95 L/kg/day in chicks, juveniles and adult emus, respectively. The safety, therapeutic efficacy and practicality of modifying the daily dose or dose interval should be considered for dose recommendations in emus.