Intranasal midazolam in green iguanas (Iguana iguana)

ABSTRACT: This study evaluated the sedation and the physiological effects produced by three doses of intranasal midazolam in green iguanas. Eight adult iguanas weighing 850 ± 165 grams, received each of five treatments: intramuscular midazolam 2 mg.kg-1 (IM), intranasally administered midazolam at doses of 2 mg.kg-1 (IN2), 3 mg.kg-1 (IN3) and 5 mg.kg-1 (IN5), and intramuscular saline (CON). The degree of sedation, heart rate, respiratory rate and body temperature were assessed from the baseline to 360 minutes post-administrations. The IM treatment induced mild to deep sedation from 10 (9 [8-12]) to 120 minutes (8 [3-9]). Sedation was not achieved in groups IN2 and IN3. When compared to the baseline, mild sedation was achieved in IN5 at 20 (5 [2-6]), 45 (5 [1-6]) and 90 minutes (5 [1-7]). There was a reduction in heart rate only in the IM group at 360 minutes (40 ± 15.1 bpm). Respiratory rate decreased to the baseline only in IN5, at 30 (12 [8-16] mpm) and 90 minutes (12 [8-24] mpm). No changes in body temperature were observed with any of the treatments during the evaluation period. Intranasally administered midazolam at a dose of 5 mg.kg-1, but not at 2 and 3 mg.kg-1, induced mild sedation in green iguanas. However, the effect exhibited a lower intensity and duration compared to the intramuscular dose of 2 mg.kg-1. Therefore, the administration of intranasal midazolam is not a reasonable option compared to the intramuscular route.