Dose Of Meloxicam Research Articles

Pharmacokinetics of meloxicam in red-eared slider turtles (Trachemys scripta elegans) after single intravenous and intramuscular injections.

OBJECTIVE To determine the pharmacokinetics of meloxicam after single IV and IM injections in red-eared slider turtles (Trachemys scripta elegans). ANIMALS 8 healthy red-eared slider turtles. PROCEDURES Turtles received 1 dose of meloxicam (0.2 mg/kg) IV or IM (4 turtles/route), a 30-day washout period was provided, and then turtles received the same dose by the opposite route. Blood samples were collected at predetermined times for measurement of plasma meloxicam concentration. Pharmacokinetic values for each administration route were determined with a 2-compartment open model approach. RESULTS For IV administration, mean ± SD values of major pharmacokinetic variables were 1.02 ± 0.41 hours for distribution half-life, 9.78 ± 2.23 hours for elimination half-life, 215 ± 32 mL/kg for volume of distribution at steady state, 11.27 ± 1.44 μg•h/mL for area under the plasma concentration versus time curve, and 18.00 ± 2.32 mL/h/kg for total body clearance. For IM administration, mean values were 0.35 ± 0.06 hours for absorption half-life, 0.72 ± 0.06 μg/mL for peak plasma concentration, 1.5 ± 0.0 hours for time to peak concentration, 3.73 ± 2.41 hours for distribution half-life, 13.53 ± 1.95 hours for elimination half-life, 11.33 ± 0.92 μg•h/mL for area under the plasma concentration versus time curve, and 101 ± 6% for bioavailability. No adverse reactions were detected. CONCLUSIONS AND CLINICAL RELEVANCE Long half-life, high bioavailability, and lack of immediate adverse reactions of meloxicam administered IM at 0.2 mg/kg suggested the possibility of safe and effective clinical use in turtles. Additional studies are needed to establish appropriate administration frequency and clinical efficacy.

An investigation of a novel behavioural test to assess pain in piglets following castration

A novel behavioural test using a handling chute was evaluated over two trials as an objective method to assess pain in piglets following castration. Piglet (n = 98) navigation time (NT) through a handling chute was measured at specific time points up to 24 h post treatment. In trial 1, comparing the NT of castrates (C) and sham castrates (SC), C piglets had a longer NT than SC at 0 and 15 min post treatment (P < 0.05), with no differences thereafter. In trial 2, the effect of an analgesic to control postoperative pain on NT was examined, with castrated piglets given a half (CH) or full (CF) dose of meloxicam 1 h prior to treatment, compared with piglets castrated and given saline (CS) or sham castrated and given saline (SS). Post treatment, CS piglets had a longer NT than SS at 0 min (P < 0.005), and at 15 min, piglets CS had a longer NT than all groups (P < 0.001). No significant associations were found between piglet behaviour in the home pen and NT during the 60 min following treatment. These data demonstrate potential for the use of a handling chute to measure NT as a quick, standardized, method to assess piglet pain in response to castration.

Metabolites derived from omega-3 polyunsaturated fatty acids are important for cardioprotection

Although controversial, some data suggest that omega-3 polyunsaturated fatty acids (PUFA) are beneficial to cardiovascular diseases, and could reduce infarct size. In parallel, we have reported that the administration of Resolvin D1 (RvD1), a metabolite of docosahexaenoic acid, an omega-3 PUFA, can reduce infarct size. The present study was designed to determine if the inhibition of two important enzymes involved in the formation of RvD1 from omega-3 PUFA could reduce the cardioprotective effect of omega-3 PUFA.Sprague–Dawley rats were fed with a diet rich in omega-3 PUFA during 10 days before myocardial infarction (MI). Two days before MI, rats received a daily dose of Meloxicam, an inhibitor of cyclooxygenase-2, PD146176, an inhibitor of 15-lipoxygenase, both inhibitors or vehicle. MI was induced by the occlusion of the left coronary artery for 40min followed by reperfusion. Infarct size and neutrophil accumulation were evaluated after 24h of reperfusion while caspase-3, -8 and Akt activities were assessed at 30min of reperfusion.Rats receiving inhibitors, alone or in combination, showed a larger infarct size than those receiving omega-3 PUFA alone. Caspase-3 and -8 activities are higher in ischemic areas with inhibitors while Akt activity is diminished in groups treated with inhibitors. Moreover, the study showed that RvD1 restores cardioprotection when added to the inhibitors.Results from this study indicate that the inhibition of the metabolism of Omega-3 PUFA attenuate their cardioprotective properties. Then, resolvins seem to be an important mediator in the cardioprotection conferred by omega-3 PUFA in our experimental model of MI.

Pharmacokinetic profiles of meloxicam in turtles (Trachemys scripta scripta) after single oral, intracoelomic and intramuscular administrations.

Meloxicam is an anti-inflammatory and analgesic drug used to treat many pathological conditions in turtles. With the aim to fill the lack of data about its pharmacokinetic in this species, eighteen turtles (Trachemys scripta scripta) were divided in three groups and treated with a single dose of meloxicam (0.2 mg/kg) by intramuscular, intracoelomic and oral route, respectively. At scheduled time points, blood samples were collected and meloxicam concentrations were determined by HPLC. Pharmacokinetic parameters were calculated from the obtained concentration-time curves. After intramuscular treatment, a plasma peak of meloxicam equal to 1590.03 ± 1845.32 ng/mL (mean ± SD) and a Tmax of 1.17 ± 0.45 h were reached, indicating a quick absorption of the drug. The intracoelomic administration brought to the largest AUC (12621.04 ± 6203.79 h*ng/mL) and to a Cmax and a Tmax equal to 1154.52 ± 662.78 ng/mL and 2.82 ± 1.39 h, respectively. Following oral treatment, the plasma concentrations of meloxicam were very low indicating a scarce absorption. Further studies are warranted to determine the effective plasma concentration of meloxicam in turtles and, consequently, the dosage regimen.

Renal, gastrointestinal, and hemostatic effects of oral administration of meloxicam to Hispaniolan Amazon parrots (Amazona ventralis).

To investigate renal, gastrointestinal, and hemostatic effects associated with oral administration of multiple doses of meloxicam to healthy Hispaniolan Amazon parrots (Amazona ventralis). 12 Hispaniolan Amazon parrots. Birds were assigned to receive meloxicam oral suspension (1.6 mg/kg, PO, q 12 h) and 2.5 mL of tap water inserted into the crop by use of a gavage tube (n = 8) or the equivalent volume of tap water only (control group; 4) for 15 days. Urine and feces were collected 2 hours after treatment administration each day. Feces were evaluated for occult blood. Results of a CBC and serum biochemical analysis and measured N-acetyl-β-d-glucosaminidase (NAG) activity and whole blood clotting time were evaluated before, during, and after completion of treatments. Results of urinalysis and measured urine NAG activity were also evaluated. Birds treated with meloxicam had a significant increase in number of WBCs and decrease in PCV from before to after treatment. The PCV also decreased significantly, compared with results for the control group; however, WBC count and PCV for all birds remained within reference ranges throughout the study. One parrot treated with meloxicam had a single high value for urine NAG activity. Meloxicam administered orally at the dosage used in this study caused no apparent negative changes in several renal, gastrointestinal, or hemostatic variables in healthy Hispaniolan Amazon parrots. Additional studies to evaluate adverse effects of NSAIDs in birds will be needed.

Identifying behavioural differences in working donkeys in response to analgesic administration

To identify pain-related behaviour in working donkeys in order to assist their owners and veterinarians to recognise and manage pain. To identify general and specific behaviours associated with pain or its relief using a trial with the nonsteroidal anti-inflammatory drug meloxicam (Metacam). Observer-blinded, placebo-controlled trial. Forty adult male working donkeys with common clinical abnormalities were randomly assigned to receive either a single loading dose of meloxicam (1.2 mg/kg bwt per os; n = 20) or a placebo (30 mg honey/250 ml water per os; n = 20). Observation of postural and event behaviours was undertaken at 2 pretreatment time points followed by 4 post treatment time points, using scan (instantaneous) and focal sampling. In comparison to pretreatment baselines, donkeys receiving meloxicam were more alert post treatment than the placebo group. They were observed lying down less frequently (P = 0.007), with their eyes closed less frequently (P = 0.04) and having a high head carriage more frequently (P = 0.02). Dozing behaviour decreased after meloxicam compared with the pretreatment baseline (P = 0.03). Donkeys given meloxicam also showed more interest in their environment, turning to look at environmental stimuli more frequently (P = 0.05) than those in the placebo group post treatment. Neither the meloxicam nor the placebo group showed a significant post treatment improvement in lameness scores. Working donkeys receiving meloxicam were more active and alert compared with their pretreatment behaviour, confirming the potential value of nonsteroidal anti-inflammatory drugs in identifying behaviours indicative of pain in working donkeys. Behavioural assessment of pain in working donkeys in field clinic conditions will enable veterinary staff and owners to identify welfare issues promptly and monitor response to analgesia. The Summary is available in Chinese--see Supporting information.

MCM-41 for Meloxicam Dissolution Improvement:in vitroRelease andin vivoBioavailability Studies

In this study, MCM-41 was prepared as a carrier for poorly water soluble drugs. Meloxicam (MLX) was selected as model compound. Textural and chemical characterizations were carried out by thermal gravimetric analysis (TGA), scanning electron microscope (SEM), nitrogen adsorption/desorption, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The in vitro release of MLX was performed at pH 1.2 and 6.8. After loading MLX into MCM-41, its oral bioavailability was compared with the free drug and the marketed product Mobic® (R) in rabbits. After administration of free MLX to rabbits (5 mg kg–1), MLX presented a two distinct double-peak profile in case of R and F2 due to enterohepatic cycling. The effect of MCM-41 was mainly on the rate not the extent of MLX absorption. Administration of free MLX to rabbits resulted in an AUC0–∞ value of 11.9 µg h mL–1 and a Tmax of 4.3 h. When the same dose of MLX was introduced as R or formulated into MCM-41 (F2; MLX to MCM-41 ratio of 0.7), the systemic exposure to MLX was raised significantly by ca. 4-fold as reflected in AUC0–∞ value of 46.9 and 45.5 µg h mL–1 for R and F2, respectively. Development of an immediate formulation could enhance the curative effect of MLX by increasing its drug release and dissolution rate in the preferential absorptive region.

Comparative Disposition Kinetics of Meloxicam Following a Single Intravenous Bolus Dose and Its Concurrent Administration with Ofloxacin in Yak and Cattle

Present study describes the comparative pharmacokinetic (PK) profile of meloxicam (0.5 mg.kg-1) alone its concurrent administration with ofloxacin (7.5 mg.kg-1) by intravenous route in yak and cattle. Plasma concentration of meloxicam was determined by HPLC assay and pharmacokinetic parameters by compartmental method using “PHARMKIT” software. Following intravenous administration of meloxicam alone, t1/2α, t1/2β, AUC, Vdarea and ClB values were found to be 0.21+0.04 h, 4.65+0.40 h, 25.46+1.22 μg/ml.h, 1.97+0.11 L/kg and 0.35+0.02 L/h/kg, respectively in yak and all these values were almost comparable to those found in cattle. But the values of K12/K21, Vc, Vp and fc differed significantly between yak and cattle. Further, no significant differences were observed in values of majority of the pharmacokinetic parameters between meloxicam alone or its concurrent administration with ofloxacin in yak and cattle except the values of Vc, Vp and T/P which differed significantly between alone and concurrent administration in yak but not in cattle. Based on pharmacokinetic variables, the loading and maintenance doses of meloxicam were found to be 1.05 and 0.88 mg.kg-1 body weight for yak and 0.97 and 0.79 mg.kg-1 for cattle and be repeated at 12 h interval. Results of present study further suggest that important pharmacokinetic parameters do not significantly differ between yak and cattle and meloxicam can be used at same dose levels in both the species and adjustment in dosage regimen of meloxicam is not warranted in either of the species, if to be used concurrently with ofloxacin.

Pharmacokinetics of meloxicam in mature swine after intravenous and oral administration.

The purpose of this study was to compare the pharmacokinetics of meloxicam in mature swine after intravenous (i.v.) and oral (p.o.) administration. Six mature sows (mean bodyweight ± standard deviation = 217.3 ± 65.68 kg) were administered an i.v. or p.o. dose of meloxicam at a target dose of 0.5 mg/kg in a cross-over design. Plasma samples collected up to 48 h postadministration were analyzed by high-pressure liquid chromatography and mass spectrometry (HPLC-MS) followed by noncompartmental pharmacokinetic analysis. Mean peak plasma concentration (CMAX ) after p.o. administration was 1070 ng/mL (645-1749 ng/mL). TMAX was recorded at 2.40 h (0.50-12.00 h) after p.o. administration. Half-life (T½ λz ) for i.v. and p.o. administration was 6.15 h (4.39-7.79 h) and 6.83 h (5.18-9.63 h), respectively. The bioavailability (F) for p.o. administration was 87% (39-351%). The results of this study suggest that meloxicam is well absorbed after oral administration.

Pharmacokinetics of single dose oral meloxicam in bottlenose dolphins (Tursiops truncatus).

The objective of this study was to investigate the pharmacokinetics of meloxicam in bottlenose dolphins (Tursiops truncatus). Ten adult bottlenose dolphins were used for the study. Each animal received a single oral dose of meloxicam at 0.1 mg/kg. Two to seven serial blood samples were collected per animal, at one of fourteen time points between T = 0 and T = 240 hr. Complete blood count and serum chemistry analysis were performed prior to drug administration, as well as at the final time point for each individual. Plasma drug concentrations were determined by high-pressure liquid chromatography. No adverse hematological, biochemical or clinical changes were noted during the study period. After oral administration, a peak plasma concentration of 1.03 microg/mL was achieved at approximately 11 hr. This suggests that a single oral dose of 0.1 mg/kg provides a peak plasma level similar to what is considered therapeutic in other species. However, the elimination of meloxicam in cetaceans was slower than in other species, with an elimination half-life of almost 70 hr, and detectable drug concentrations up to 7 days. A single oral dose of 0.1 mg/kg appears safe for use in this species, but caution in repeated dosing must be used, due to the prolonged elimination, until multi-dose pharmacokinetic studies are determined.

Mavacoxib and meloxicam for canine osteoarthritis: a randomised clinical comparator trial

NSAIDs are the cornerstone of medical management of canine osteoarthritis (OA). Meloxicam is a daily-administered NSAID widely available in a liquid formulation and manufacturer's summary of product characteristics (SPC) advise...

Strongly increased exposure of meloxicam in CYP2C9*3/*3 individuals

The effects of CYP2C9*1/*3 and *3/*3 genotypes on the pharmacokinetics and pharmacodynamics of meloxicam were evaluated in healthy Korean subjects. After oral administration of 15 mg meloxicam, the plasma concentrations of meloxicam were assessed in 11 CYP2C9*1/*1 individuals, eight CYP2C9*1/*3 individuals, and three CYP2C9*3/*3 individuals. The pharmacodynamic effects were determined by measuring thromboxane B2 generated in blood. A nine-fold lower apparent oral clearance and an eight-fold higher AUC0-∞ of single-dose meloxicam were observed in CYP2C9*3/*3 individuals when compared with CYP2C9*1/*1 individuals. CYP2C9*3/*3 individuals also showed markedly increased inhibition of thromboxane B2 generation by meloxicam. These results indicate that CYP2C9*3/*3 individuals may be at a higher risk for concentration-dependent adverse effects during long-term treatment with standard doses of meloxicam.

Meloxicam pharmacokinetics using nonlinear mixed‐effects modeling in ferrets after single subcutaneous administration

This study was designed to investigate the pharmacokinetics of meloxicam, an oxicam class, nonsteroidal anti-inflammatory drug (NSAID), in ferrets. We determined the pharmacokinetic properties of a single subcutaneous dose of meloxicam (0.2 mg/kg) in nine male and nine female ferrets. Blood samples were collected by venipuncture of the cranial vena cava into heparinized syringes. Plasma meloxicam concentrations were determined by high-pressure liquid chromatography (HPLC). Pharmacokinetic variables were calculated using nonlinear mixed-effects modeling to take advantage of the population-based sampling scheme and to minimize sample volume collected per animal. Maximum plasma concentration, volume of distribution per absorption, and elimination half-life were 0.663 μg/mL, 0.21 L, and 11.4 h, respectively, for females and 0.920 μg/mL, 0.35 L, and 17.8 h, respectively, for males. Significant differences were found in each of the above parameters between male and female ferrets. Systemic clearance per absorption was not affected by gender and was 13.4 mL/h. Analgesic efficacy was not evaluated, but plasma meloxicam concentrations achieved in these animals are considered effective in other species. Sex differences in the pharmacokinetic behavior of meloxicam should be taken into consideration when treating ferrets.

Gut-liver axis improves with meloxicam treatment after cirrhotic liver resection.

To investigate the effect of meloxicam on the gut-liver axis after cirrhotic liver resection. Forty-four male Wistar rats were assigned to three groups: (1) control group (CG); (2) bile duct ligation with meloxicam treatment (BDL + M); and (3) bile duct ligation without meloxicam treatment (BDL). Secondary biliary liver cirrhosis was induced via ligature of the bile duct in the BDL + M and BDL groups. After 2 wk, the animals underwent a 50% hepatectomy. In the BDL + M group 15 min prior to the hepatectomy, one single dose of meloxicam was administered. Parameters measured included: microcirculation of the liver and small bowel; portal venous flow (PVF); gastrointestinal (GI) transit; alanine aminotransferase (ALT); malondialdehyde; interleukin 6 (IL-6), transforming growth factor beta 1 (TGF-β1) and hypoxia-inducible factor 1 alpha (HIF-1α) levels; mRNA expression of cyclooxigenase-2 (COX-2), IL-6 and TGF-β1; liver and small bowel histology; immunohistochemical evaluation of hepatocyte and enterocyte proliferation with Ki-67 and COX-2 liver expression. Proliferative activity of hepatocytes after liver resection, liver flow and PVF were significantly higher in CG vs BDL + M and CG vs BDL group (P < 0.05), whereas one single dose of meloxicam ameliorated liver flow and proliferative activity of hepatocytes in BDL + M vs BDL group. COX-2 liver expression at 24 h observation time (OT), IL-6 concentration and mRNA IL-6 expression in the liver especially at 3 h OT, were significantly higher in BDL group when compared with the BDL + M and CG groups (P < 0.01, P < 0.001, P < 0.01, respectively). Liver and small bowel histology, according to a semi quantitative scoring system, showed better integrity in BDL + M and CG as compared to BDL group. ALT release and HIF-1α levels at 1 h OT were significantly higher in BDL + M compared to CG and BDL group (P < 0.001 and P < 0.01, respectively). Moreover, ALT release levels at 3 and 24 h OT were significantly higher in BDL group compared to CG, P < 0.01. GI transit, enterocyte proliferative activity and number of goblet cells were in favor of meloxicam treatment vs BDL group (P < 0.05, P < 0.001, P < 0.01, respectively). Additionally, villus length were higher in BDL + M as compared to BDL group. One single dose of meloxicam administered after cirrhotic liver resection was able to cause better function and integrity of the remaining liver and small bowel.

The concomitant use of meloxicam and methotrexate does not clearly increase the risk of silent kidney and liver damages in patients with rheumatoid arthritis

We investigated whether the concomitant use of meloxicam and methotrexate might induce kidney and liver damages in patients with rheumatoid arthritis (RA). We enrolled 101 RA patients with normal kidney and liver functions taking meloxicam and methotrexate concomitantly for more than 6 months. Blood and urine tests were performed. Estimated glomerular filtration rate (eGFR) and liver stiffness measurement (LSM) were used for evaluating silent kidney and liver damages. Ultrasonography was also performed to exclude structural abnormalities. We adopted 90 mL/min/1.73 mm(2) and 5.3 kPa as the cutoff for an abnormal eGFR and LSM. The mean age (85 women) was 51.9 years. The mean eGFR was 97.0 mL/min/1.73 m(2) and the mean LSM was 4.7 kPa. The mean weekly dose of methotrexate was 13.4 mg. The mean weekly dose of methotrexate did not correlate with eGFR or LSM. Neither the cumulative dose of meloxicam or methotrexate nor the mean weekly dose of methotrexate showed the significant odds ratio or relative risk for abnormal eGFR and LSM values. The use of higher-dose MTX, above 15 mg per week, with meloxicam did not significantly increase the risk for abnormal LSM and eGFR (RR = 2.042, p = 0.185; RR = 0.473, p = 0.218). The concomitant use of meloxicam and MTX did not clearly increase the risk of silent kidney or liver damage in RA patients with normal laboratory results taking MTX and meloxicam concurrently for over 6 months.

Meloxicam‐Induced Thrombocytopenia

Immune thrombocytopenia can have several causes including the use of certain drugs. Thrombocytopenia has been documented as a rare adverse effect of some nonsteroidal antiinflammatory drugs (NSAIDs) including diclofenac, naproxen, and ibuprofen. However, only one previously documented case of meloxicam-associated thrombocytopenia has been reported in the literature. We describe an 84-year-old woman who developed a case of immune-mediated thrombocytopenia that was attributed to meloxicam therapy. The patient's platelet count decreased from a baseline of 267×10(3) /mm(3) to 2×10(3) /mm(3) 1week after she received her first lifetime dose of meloxicam. She also experienced black stools and bruising that coincided with the meloxicam administration. The almost immediate onset of thrombocytopenia and symptoms after initiation of meloxicam, as well as the marked reduction in her platelet count, suggest an idiosyncratic reaction. According to the Hill criteria for assessing causality of adverse drug events, it is plausible that this reaction was due to meloxicam. Health care providers should be aware of the possibility of thrombocytopenia secondary to NSAID therapy including meloxicam. Immune thrombocytopenia can be life threatening if it is not identified and treated promptly. A thorough medication history is particularly important when patients present with unusual symptoms, with a focus on those drugs that have been recently initiated. Although thrombocytopenia is a rare adverse effect of NSAID therapy, it should be considered a potential cause in patients receiving these drugs who have signs and symptoms consistent with this blood dyscrasia.

Pharmacokinetics of a Single Dose of Intravenous and Oral Meloxicam in Red-tailed Hawks (Buteo jamaicensis) and Great Horned Owls (Bubo virginianus)

Pharmacokinetic data were determined after a single dose of meloxicam in red-tailed hawks (RTH; Buteo jamaicensis) and great horned owls (GHO; Bubo virginianus). In a nonrandomized crossover design, individual birds of each species received 1 dose of intravenous meloxicam (0.5 mg/kg i.v.; n = 7 for each species) followed by a 2-week washout period, and then each received 1 dose of oral meloxicam (0.5 mg/kg PO; n = 5 for each species). Blood samples were collected intermittently after administration, and meloxicam was detected in plasma by high-performance liquid chromatography. Time versus plasma concentration data were subjected to noncompartmental analysis. Red-tailed hawks were determined to have the shortest elimination half-life for meloxicam (0.49 +/- 0.5 hours) of any species documented. Great horned owls also eliminated meloxicam very rapidly (0.78 +/- 0.52 hours). Great horned owls achieved higher plasma concentrations (368 +/- 87 ng/mL) of meloxicam than RTH (182 +/- 167 ng/mL) after oral administration, although RTH had a markedly higher volume of distribution (832 +/- 711 mL/kg) than GHO (137.6 +/- 62.7 mL/kg). The differences in meloxicam pharmacokinetics between these 2 raptor species supports the need for species-dependent studies and underlines the challenges of extrapolating drug dosages between species. Results of this study suggest that the current recommended once-daily dosing interval of oral meloxicam is unlikely to maintain plasma concentrations anticipated to be therapeutic in either RTH or GHO, and practical dosing options are questionable for this nonsteriodal anti-inflammatory drug in these raptor species.

Pharmacokinetics of meloxicam in rabbits after oral administration of single and multiple doses

To determine the pharmacokinetics of meloxicam (1 mg/kg) in rabbits after oral administration of single and multiple doses. 6 healthy rabbits. A single dose of meloxicam (1 mg/kg, PO) was administered to the rabbits. After a 10-day washout period, meloxicam (1 mg/kg, PO) was administered to rabbits every 24 hours for 5 days. Blood samples were obtained from rabbits at predetermined intervals during both treatment periods. Plasma meloxicam concentrations were determined, and noncompartmental pharmacokinetic analysis was performed. The mean peak plasma concentration and area under the plasma concentration-versus-time curve extrapolated to infinity after administration of a single dose of meloxicam were 0.83 μg/mL and 10.37 h•μg/mL, respectively. After administration of meloxicam for 5 days, the mean peak plasma concentration was 1.33 μg/mL, and the area under the plasma concentration-versus-time curve from the time of administration of the last dose to 24 hours after that time was 18.79 h•μg/mL. For single- and multiple-dose meloxicam experiments, the mean time to maximum plasma concentration was 6.5 and 5.8 hours and the mean terminal half-life was 6.1 and 6.7 hours, respectively. Plasma concentrations of meloxicam for rabbits in the present study were proportionally higher than those previously reported for rabbits receiving 0.2 mg of meloxicam/kg and were similar to those determined for animals of other species that received clinically effective doses. A dose of 1 mg/kg may be necessary to achieve clinically effective circulating concentrations of meloxicam in rabbits, although further studies are needed.

Pharmacokinetics of meloxicam after intravenous, intramuscular, and oral administration of a single dose to Hispaniolan Amazon parrots (Amazona ventralis)

To compare pharmacokinetics after IV, IM, and oral administration of a single dose of meloxicam to Hispaniolan Amazon parrots (Amazona ventralis). 11 healthy parrots. Cohorts of 8 of the 11 birds comprised 3 experimental groups for a crossover study. Pharmacokinetics were determined from plasma concentrations measured via high-performance liquid chromatography after IV, IM, and oral administration of meloxicam at a dose of 1 mg/kg. Initial mean ± SD plasma concentration of 17.3 ± 9.0 μg/mL was measured 5 minutes after IV administration, whereas peak mean concentration was 9.3 ± 1.8 μg/mL 15 minutes after IM administration. At 12 hours after administration, mean plasma concentrations for IV (3.7 ± 2.5 μg/mL) and IM (3.5 ± 2.2 μg/mL) administration were similar. Peak mean plasma concentration (3.5 ± 1.2 μg/mL) was detected 6 hours after oral administration. Absolute systemic bioavailability of meloxicam after IM administration was 100% but was lower after oral administration (range, 49% to 75%). Elimination half-lives after IV, IM, and oral administration were similar (15.9 ± 4.4 hours, 15.1 ± 7.7 hours, and 15.8 ± 8.6 hours, respectively). Pharmacokinetic data may provide useful information for use of meloxicam in Hispaniolan Amazon parrots. A mean plasma concentration of 3.5 μg/mL would be expected to provide analgesia in Hispaniolan Amazon parrots; however, individual variation may result in some birds having low plasma meloxicam concentrations after IV, IM, or oral administration. After oral administration, meloxicam concentration slowly reached the target plasma concentration, but that concentration was not sustained in most birds.

Pharmacokinetics and Safety of Oral Administration of Meloxicam to Foals

The pharmacokinetics, efficacy, and safety of meloxicam have been evaluated in adult horses, but not foals. Physiologic differences between neonates and adults might alter drug pharmacokinetics and therapeutic index. The pharmacokinetics of meloxicam will be different in foals compared with adult horses, and foals could be at increased risk for adverse drug effects. Twenty lightbreed foals less than 6weeks of age at commencement of the study. Single and repeated oral dose pharmacokinetics were determined for meloxicam (0.6mg/kg) in 10 foals. The safety of the drug was further evaluated in a 2nd group of 10 foals in a randomized blinded prospective study. Plasma concentrations after a single oral dose of meloxicam (0.6mg/kg) and time to maximum plasma concentration were similar to adult horses. However, drug clearance was much more rapid in foals (elimination half-life 2.48±0.25hours). Administration of 0.6mg/kg every 12hours was well tolerated by foals for up to 3weeks, with no evidence of drug accumulation in plasma. Adverse effects observed in adult horses at higher dose rates were not observed in foals given 1.8mg/kg twice daily for 7days. Meloxicam at an oral dose rate of 0.6mg/kg every 12hours provided plasma concentrations likely to be therapeutic. In contrast to findings for other NSAIDs, foals appeared more resilient to the adverse effects of this drug than was observed in adult horses.