Meloxicam livre e Meloxicam nanoencapsulado como adjuvantes na analgesia trans e pós-operatória em cadelas submetidas à ovariohisterectomia

Abstract

Meloxicam is a potent anti-inflammatory drug used in treatment of musculoskeletal pain, inflammation and pre and postoperative management. This drug has high intestinal permeability and low aqueous solubility, with dissolution being its limiting factor for absorption. Common side effects include gastrointestinal problems. Nanocarriers have the ability to increase the bioavailability of drugs, decreasing the necessary dose and adverse effects. The present study aims to compare free meloxicam and nanoencapsulated meloxicam as adjuvants in trans and postoperative analgesia in bitches submitted to ovariohysterectomy. Twenty healthy adult female dogs were randomly distributed in the “ML” group (free meloxicam) and in the “MNano” group (nanoencapsulated meloxicam). The dose treatment was 0.2 mg kg-1 , via oral, four hours before the surgical procedure. The trans operative analgesia was performed during the surgical procedure. The postoperative pain assessment was performed during 48 hours after the procedure. The supplemental analgesia was recommended for values equal to or greater than 6/24 in the Modified Glasgow Scale and 30mm in the Visual Analogue Scale. Buccal mucosa bleeding time was measured before the administration of meloxicam, after 4 hours, in the end of surgical procedure and 12 hours after drug administration. In addition, creatinine was measured one week before surgery, 24 and 48 hours after meloxicam administration. The formulations did not exclude the use of supplementary analgesia in the trans operative period. There was no significant difference between the numbers of rescued in the two groups (p> 0.05). The animals did not require rescue analgesia after surgery and there were no clinically relevant differences in the assessment of pain scales between groups (p> 0.05). There were no changes in mucosa bleeding time and creatinine. Two animals presented vomiting and one animal presented aquesia followed by bloody stools in ML group in postoperative period. The nanoencapsulated meloxicam promoted satisfactory postoperative analgesia in a single dose, via oral, four hours before the surgical procedure in healthy dogs submitted to ovariohysterectomy. There was no difference between groups in the transoperative analgesia and only animals treated with free meloxicam had side effects related to the gastrointestinal tract in postoperative period. The nanostructured formulation is safe and effective and is an alternative formulation to commercial products.