EFEITOS DA CLONIDINA E DA RILMENIDINA SOBRE OS SISTEMAS CARDIORRESPIRATÓRIO E GASTROINTESTINAL DE EQUINOS EFFECTS OF CLONIDINE AND RILMENIDINE ON CARDIORESPIRATORY AND GASTROINTESTINAL SYSTEMS OF HORSES

Clonidine and rilmenidine are drugs used in human medicine as central acting antihypertensive agents due to their actions on the alpha 2 -adrenoceptor and I 1 imidazoline receptors in the central nervous system. Currently, clonidine is also used as a pre-anesthetic medication and in spinal anesthesia, and rilmenidine, despite the lower selectivity for alpha 2 -adrenergic receptors than clonidine, has also shown antinociceptive potential in experimental pain models. In this study, six horses were submitted to four treatments: R1 group (0.014 mg/kg of rilmenidine); R2 group (0.021 mg/kg of rilmenidine); Clo group (0.002 mg/kg of clonidine), and a control group. The assessment comprehended their heart and respiratory rates, systolic blood pressure and intestinal motility at basal levels and, then, 60 and 120 minutes after the oral administration of the drugs. Rilmenidine decreased heart rate on the