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Meloxicam in Rabbits
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A D V A N C E S
effects. NSAIDs are effective in treating postoperative pain in dogs and cats without producing adverse effects, such as sedation, ileus, dysphoria, and hypothermia, which are typically associated with opioids. The adverse effects associated with NSAIDs most commonly involve gastrointestinal tract injury and, occasionally, impairment of renal blood flow. Gastrointestinal perforation, ulceration, and bleeding have been associated with NSAID-induced depression of normal prostaglandin E2-mediated mucosal protective mechanisms as well as direct local irritation. Meloxicam, a COX-2 selective NSAID, has anti-inflammatory, analgesic, and antipyretic properties that have been established in experimental and clinical studies in dogs and cats. Because of its COX-2 selectivity, meloxicam may have less adverse effects such as gastrointestinal ulcers and inhibition of platelet function. The plasma or serum half-life of meloxicam is species specific, and it is difficult to extrapolate data across species. However, there are very few research studies on the pharmacokinetics of NSAIDS in small mammal, non-traditional pets.
Objectives To determine the pharmacokinetics and safety of meloxicam in rabbits when administered orally for 29 days.
Procedure Meloxicam (1.0 mg/kg, by mouth, once per day) was administered to 6 clinically healthy rabbits for 29 days. Blood was collected immediately before (time 0) and 2, 4, 6, 8, and 24 hours after drug administration on days 1, 8, 15, 22, and 29 to evaluate the pharmacokinetics of meloxicam. On day 30, an additional sample was collected 36 hours after treatment. Plasma meloxicam concentrations were determined. Weekly plasma biochemical analyses were performed to evaluate any adverse physiologic effects. Rabbits were euthanized for necropsy on day 31.
MELOXICAM IN RABBITS Results Background Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common forms of analgesia. These drugs work centrally and peripherally to prevent pain and have analgesic and anti-inflammatory
Mean peak plasma concentrations of meloxicam after administration of doses 1, 8, 15, 22, and 29 were 0.67 ± 0.19, 0.81 ± 0.21, 100 ± 0.31, 1.00 ± 0.29, and 1.07 ± 0.19 μg/ml, respectively. These concentrations did not differ significantly among
A D V A N C E S
doses 8 through 29. Results of plasma biochemical analyses were within reference ranges at all time points evaluated. Gross necropsy and histologic examination of tissues revealed no clinically relevant findings.
Author Conclusion Plasma concentrations of meloxicam for rabbits in the present study were similar to those previously reported in rabbits that received 1.0 mg of meloxicam/kg, by mouth, every 24 hours, for 5 days. Results suggested that a dosage of 1.0 mg/kg, by mouth, every 24 hours for up to 29 days may be safe for use in healthy rabbits.
Inclusions One figure, 1 table, 22 references.
Editor Annotation Meloxicam is a commonly used analgesic in exotic mammal practice. Recently published current dose recommendations are 0.2 to 0.3 mg/kg orally, subcutaneously, or intramuscularly. The purpose of this study was to determine pharmacokinetics and safety of this drug administered at 1.0 mg/ kg, by mouth, for 29 days. Meloxicam at this dose was found to be well tolerated, and no rabbit displayed changes in behavior or in physical examination parameters. Biochemical parameters remained within normal limits, and at the conclusion of this study, no abnormalities were found at necropsy that could be attributed to drug administration. Pharmacokinetics demonstrated that the 1.0 mg/kg dose resulted in plasma drug levels consistent with clinically effective (but lower) dosages in other species. Two points should be kept in mind: 1. While this dose maintained what appeared to be acceptable drug plasma levels, the study did not attempt to evaluate efficacy. 2. No untoward effects were seen in healthy rabbits given 1.0 mg/kg. As chronic renal failure is common in older rabbits, caution should be used when using this drug at higher dosages or for prolonged periods in any older or debilitated rabbit. (AML) Delk KW, Carpenter JW, KuKanich B, et al. Pharmacokinetics of meloxicam administered orally to rabbits (Oryctolagus cuniculus) for 29 days. Am J Vet Res 2014;75:195-199.
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A D V A N C E S
effects. NSAIDs are effective in treating postoperative pain in dogs and cats without producing adverse effects, such as sedation, ileus, dysphoria, and hypothermia, which are typically associated with opioids. The adverse effects associated with NSAIDs most commonly involve gastrointestinal tract injury and, occasionally, impairment of renal blood flow. Gastrointestinal perforation, ulceration, and bleeding have been associated with NSAID-induced depression of normal prostaglandin E2-mediated mucosal protective mechanisms as well as direct local irritation. Meloxicam, a COX-2 selective NSAID, has anti-inflammatory, analgesic, and antipyretic properties that have been established in experimental and clinical studies in dogs and cats. Because of its COX-2 selectivity, meloxicam may have less adverse effects such as gastrointestinal ulcers and inhibition of platelet function. The plasma or serum half-life of meloxicam is species specific, and it is difficult to extrapolate data across species. However, there are very few research studies on the pharmacokinetics of NSAIDS in small mammal, non-traditional pets.
Objectives To determine the pharmacokinetics and safety of meloxicam in rabbits when administered orally for 29 days.
Procedure Meloxicam (1.0 mg/kg, by mouth, once per day) was administered to 6 clinically healthy rabbits for 29 days. Blood was collected immediately before (time 0) and 2, 4, 6, 8, and 24 hours after drug administration on days 1, 8, 15, 22, and 29 to evaluate the pharmacokinetics of meloxicam. On day 30, an additional sample was collected 36 hours after treatment. Plasma meloxicam concentrations were determined. Weekly plasma biochemical analyses were performed to evaluate any adverse physiologic effects. Rabbits were euthanized for necropsy on day 31.
MELOXICAM IN RABBITS Results Background Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common forms of analgesia. These drugs work centrally and peripherally to prevent pain and have analgesic and anti-inflammatory
Mean peak plasma concentrations of meloxicam after administration of doses 1, 8, 15, 22, and 29 were 0.67 ± 0.19, 0.81 ± 0.21, 100 ± 0.31, 1.00 ± 0.29, and 1.07 ± 0.19 μg/ml, respectively. These concentrations did not differ significantly among
A D V A N C E S
doses 8 through 29. Results of plasma biochemical analyses were within reference ranges at all time points evaluated. Gross necropsy and histologic examination of tissues revealed no clinically relevant findings.
Author Conclusion Plasma concentrations of meloxicam for rabbits in the present study were similar to those previously reported in rabbits that received 1.0 mg of meloxicam/kg, by mouth, every 24 hours, for 5 days. Results suggested that a dosage of 1.0 mg/kg, by mouth, every 24 hours for up to 29 days may be safe for use in healthy rabbits.
Inclusions One figure, 1 table, 22 references.
Editor Annotation Meloxicam is a commonly used analgesic in exotic mammal practice. Recently published current dose recommendations are 0.2 to 0.3 mg/kg orally, subcutaneously, or intramuscularly. The purpose of this study was to determine pharmacokinetics and safety of this drug administered at 1.0 mg/ kg, by mouth, for 29 days. Meloxicam at this dose was found to be well tolerated, and no rabbit displayed changes in behavior or in physical examination parameters. Biochemical parameters remained within normal limits, and at the conclusion of this study, no abnormalities were found at necropsy that could be attributed to drug administration. Pharmacokinetics demonstrated that the 1.0 mg/kg dose resulted in plasma drug levels consistent with clinically effective (but lower) dosages in other species. Two points should be kept in mind: 1. While this dose maintained what appeared to be acceptable drug plasma levels, the study did not attempt to evaluate efficacy. 2. No untoward effects were seen in healthy rabbits given 1.0 mg/kg. As chronic renal failure is common in older rabbits, caution should be used when using this drug at higher dosages or for prolonged periods in any older or debilitated rabbit. (AML) Delk KW, Carpenter JW, KuKanich B, et al. Pharmacokinetics of meloxicam administered orally to rabbits (Oryctolagus cuniculus) for 29 days. Am J Vet Res 2014;75:195-199.
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