Hyoscine may represent an alternative to atropine for treating bradycardia.

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BackgroundThis study evaluated and compared cardiorespiratory and blood gas parameters, as well as sedation, analgesia and recovery of two protocols: ketamine (10 mg/kg) or dexmedetomidine (10 μg/kg), with midazolam (0.5 mg/kg) and butorphanol (0.3 mg/kg), IM (KBM and DBM, respectively) in brown howler monkeys (Alouatta guariba clamitans).Material and methodsTwelve brown howler monkeys were selected in two groups and evaluated for cardiorespiratory parameters and sedation, from 5‐30 minutes after latency. Blood gas and arterial lactate were taken at 5 and 30 minutes. In the end, time and quality of recovery were evaluated.ResultsThe HR in DBM group was significantly lower at all times. The sedation score was higher in DBM. Recovery in DBM was faster. All animals had moderate hypoxaemia.ConclusionBoth protocols produce satisfactory anaesthesia and analgesia, but DBM provides deeper sedation with faster recovery. Oxygen supplementation is recommended in both due to hypoxaemia.

We investigated the thermal, electrical and mechanical antinociceptive and physiological effects (heart rate, respiratory rate, arterial blood pressure, head height and abdominal auscultation score), and pharmacokinetics, of 0.5 mg/kg of the injectable formulation (ORAL) or nanoparticulated methadone (NANO) given orally, in six adult mares, using a crossover, blind and prospective design. Repeated-measure models were used to compare parametric data between and within treatments, followed by Tukey's test. Nonparametric data were analysed with Wilcoxon signed-rank, adjusted by Bonferroni tests. Blood samples were also collected up to 6 h after dosing for plasma drug quantification by LC-MS/MS. Methadone pharmacokinetic parameters were determined by noncompartmental and compartmental approaches. There were no differences in pharmacodynamic parameters. No statistical differences were observed in the pharmacokinetic parameters from noncompartmental analysis for both groups, except a significant decrease in peak plasma concentration, increase in apparent volume of distribution per fraction absorbed (Vd /F) and increased mean residence time (MRT) for NANO. One-compartment open model with first order elimination best described the pharmacokinetic profiles for both groups. Neither ORAL nor NANO administered orally to horses produced antinociception. The nanoencapsulated formulation of methadone given orally to horses did not improve methadone pharmacokinetic parameters or increased systemic body exposure to methadone.

Objectives. The aim of the study is to compare the sedative, cardiorespiratory, echocardiographic, and blood gas effects of dexmedetomidine and methadone associated or not with midazolam for restraint chemistry in cats. Methods. Eighteen healthy young cats (4.06 ± 0.48 kg) were randomly sedated with two protocols, through the intramuscular route: dexmedetomidine (5 µg.kg−1), methadone (0.3 mg. kg−1) and midazolam (0.3 mg. kg−1) (DMTM, n = 9), or dexmedetomidine (7.5 µg.kg−1) and methadone (0.3 mg. kg−1) (DMT, n = 9). The cardiorespiratory parameters were measured at baseline, 5 and 10 minutes after pharmacological latency. The sedation, analgesia, and muscle relaxation scores were assessed before and 5 minutes after pharmacological latency, while arterial blood gas analysis and echocardiography were assessed before and after 10 or 15 minutes, respectively. Results. There was no difference between the protocols regarding the cardiorespiratory, blood gas, and echocardiographic parameters used. The scores for sedation, analgesia, and muscle relaxation also did not differ between the protocols, with the degree of sedation, analgesia, and myorelaxation considered satisfactory in both groups. A significant decrease in heart rate (HR) was observed after administration of the sedative protocols, reaching a maximum reduction at T10 (46% and 53% reduction in the DMT and DMTM groups, respectively). The reduction in HR had an impact on echocardiographic parameters such as CO, which decreased 53% and 56% in the DMT and DMTM groups, respectively. There was a significant reduction in PaO2, SaO2, ejection fraction, and fractional shortening in both protocols. SpO2 decreased significantly after 5 minutes of sedation in the DMT group, but with a minimum mean SpO2 of 92% in T5. The respiratory rate decreased significantly at 5 and 10 minutes in the DMTM group, while PaCO2 increased in both groups, indicating respiratory depression caused by the drugs. Conclusions and Relevance. The study pointed out that both sedative protocols can be recommended for clinical sedation of young and healthy cats in the doses used. However, both protocols resulted in cardiorespiratory depression in cats and also the particularities of the animals should be evaluated regarding reducing cardiac output by more than 50%.