The effective dose of butorphanol tartrate in patients of different ages undergoing painless gastroscopy.

OBJECTIVE: This study evaluated the 50% effective dose (ED50) and 95% effective dose (ED95) of butorphanol tartrate in patients undergoing painless gastroscopy. METHODS: Patients who underwent painless gastroscopy at Binzhou Medical University Hospital were divided into the youth, middle-aged, and older groups. The ED50 and ED95 required for successful sedation using butorphanol tartrate were measured using the Dixon up-and-down method in patients in the different age groups. Patients in each group were administered intravenous butorphanol 5 minutes before gastroscopy. Each patient was administered 2 mg/kg propofol. The ED50 and ED95 of butorphanol were calculated using probit analysis. RESULTS: In total, 95 patients were included. The ED50s of butorphanol in the youth, middle-aged, and older groups were 7.384, 6.657, and 6.364 µg/kg, respectively. The ED95s of butorphanol doses in these groups were 9.108, 8.419, and 7.348 µg/kg, respectively. CONCLUSIONS: The ED50 and ED95 varied among the age groups, indicating that the effective dose decreases with age.

EVALUATION OF A BUTORPHANOL-MIDAZOLAM-MEDETOMIDINE PROTOCOL FOR SHORT PROCEDURES IN LESSER CHEVROTAINS (TRAGULUS SP.).

Twenty lesser chevrotains (Tragulus sp.), 10 males and 10 females, were anesthetized with a combination of butorphanol-midazolam-medetomidine (BMidM), to assess the efficacy of this protocol for short procedures in this genus. The animals received BMidM (0.32, 0.06, 0.15 mg/kg, respectively) intramuscularly via hand injection. Physiological variables were recorded once the animals reached a working depth of anesthesia that lasted 30 min (range 12-60 min). At the end of the procedure, medetomidine and butorphanol were antagonized with atipamezole (0.75 mg/kg) and naltrexone (0.3 mg/kg) intramuscularly, respectively. Induction and recovery were 9.4 ± 4.0 min and 10.2 ± 4.1 min, respectively. Supplementation with isoflurane via face mask was required in five animals to reach light anesthesia. Times to reach the various stages of anesthesia were compared between sexes. There was no difference between males and females reaching the different stages of anesthesia, except for the time required to reach the ambulatory stage, in which females took a significantly longer time (11.8 min vs 7.8 min for the males) to stand after the injection of the antagonists (P = 0.02). Heart rate, respiratory rate, rectal temperature, and peripheral hemoglobin oxygen saturation were similar between sexes and stable throughout the procedure. At the dosage tested BMidM was a reliable and safe protocol for short, minimally invasive procedures in lesser chevrotains with a fast induction and smooth recovery without complications.

IMMOBILIZATION OF BLACK HOWLER MONKEYS (ALOUATTA PIGRA) USING BUTORPHANOL, AZAPERONE, MEDETOMIDINE IS SAFE AND EFFECTIVE FOR NONINVASIVE PROCEDURES.

Administration of butorphanol, azaperone, and medetomidine (BAM) for immobilization of black howler monkeys (Alouatta pigra) has not been previously reported. In this observational study, 0.02 ml/kg of compounded BAM (butorphanol 27.3 mg/ml, azaperone 9.1 mg/ml, medetomidine 10.9 mg/ml) was administered IM in 10 captive black howler monkeys. Time to immobilization was recorded, an arterial blood gas performed, and at 5-min intervals, HR, RR, oscillometric arterial blood pressure, SPO2, and rectal temperature were measured. Naltrexone and atipamezole were administered IM at procedure completion and recovery times were recorded. If invasive procedures such as surgery were necessary and additional drugs needed, further data from that individual was removed from data analysis. Final BAM dosages were 0.55 ± 0.12 mg/kg butorphanol, 0.19 ± 0.04 mg/kg azaperone, and 0.22 ± 0.05 mg/kg medetomidine. Nine of 10 monkeys achieved sedation allowing for physical exam, venipuncture, and tuberculin skin testing within 4 ± 2 min. No monkeys reached a plane of immobilization allowing for intubation. Physiologic variables were acceptable for this species. Hypoxemia (SPO2 < 95%) was observed in three monkeys via pulse oximetry, and normoxemia was observed on arterial blood gas. Recovery was smooth and rapid. Therefore, BAM is a viable option for noninvasive procedures or as a premedication prior to induction of anesthesia in black howler monkeys.

Post-surgical photobiomodulation therapy improves outcomes following elective gastropexy in dogs.

PURPOSE: To evaluate the effect of post-surgical photobiomodulation therapy in dogs. METHODS: Twenty dogs were selected for elective gastropexy and randomly divided into a control (CG, n = 10) and a PBMT group (PBMTG, n = 10). Pre­medication consisted of medetomidine and butorphanol. Meloxicam was administered before the procedure. Induction was performed with propofol and maintained with sevoflurane. Local blocks with lidocaine were used. Incisional gastropexy was performed in all animals. PBMTG received PBMT immediately after surgery. The need for postoperative rescue analgesia, if the animal had eaten by the evaluation momen, and pain scores were collected using the Glasgow Composite Measure Pain Scale - Short Form (CMPS­SF) at 1, 2, 4, 6, 8, 12, 16, 20, and 24 h post­endotracheal extubation. CMPS­SF scores were compared with the Mann-Whitney Test and proportions of animals that required rescue analgesia and had eaten with a χ2 test. P was set at < 0.05. RESULTS: No rescue analgesia was needed for any animal. Still, significant differences were observed in CMPS-SF scores between CG and PBMTG between 1 and 4 h post-extubation. PBMTG had a significantly higher proportion of animals eating up to the 8 h post-extubation evaluation moment. CONCLUSION: Adding post-surgical photobiomodulation to a standard anesthesia and analgesia protocol reduced CMPS-SF scores and increased the proportion of animals that resumed eating compared to the standard protocol alone.

Comparison of Manual Restraint With and Without Sedation on Outcomes for Wild Birds Undergoing Decontamination.

The decontamination process for plumage-contaminated wild birds, such as those affected by oil spills, is lengthy and involves manual restraint and manipulation of all body parts. Birds commonly react to this in ways that suggest they are extremely stressed (eg, struggling, vocalizing). We proposed to reduce stress during the wash process using sedation and hypothesized that the use of sedation would not negatively impact survival. Contaminated birds in need of washing were randomly selected to be either sedated (butorphanol 2 mg/kg IM + midazolam 1 mg/kg IM and flumazenil 0.1 mg/kg IM for reversal) or not sedated at 3 US rehabilitation centers over the course of 1 year. Response to sedation was rated on a scale of 0-4 with 0 as no effect to 4 as excessively sedate. Data such as cloacal temperatures at various time points, lengths of various portions of the wash process, preening behavior in the drying pen, and disposition were collected. No statistical differences were found between sedated and nonsedated birds for any of the data points collected, including survival. There was a significant association between birds with higher cloacal temperatures in the drying pen and with birds held longer in the drying pen with improved survival; however, these findings were unrelated to whether the birds were sedated. Our findings show that sedation with butorphanol 2 mg/ kg IM and midazolam 1 mg/kg IM reversed with flumazenil 0.1 mg/kg IM can be used during the wash process for wild birds without adverse effects. Careful attention must be given to heat support for all birds while drying to prevent hypothermia.

Comparative study of the effects of antitussive drugs in a canine acute cough model.

BACKGROUND: Cough is a common clinical complaint in small animal practice with limited treatment options for chronic underlying conditions. OBJECTIVES: The present study aimed to evaluate the efficacy of three antitussive drugs in a novel, minimally invasive canine acute cough model. METHODS: Five clinically healthy Beagles were used to create an acute cough model by administering sterile saline via a transtracheally placed central venous catheter. Single-dose antitussive effects of butorphanol, maropitant and Danpron were assessed. Cough frequency was measured before and at hourly intervals up to 3 h post-administration of each drug, with a linear mixed model used for statistical analysis. RESULTS: Butorphanol (0.3 m/kg, IM) significantly reduced cough frequency at 1 and 3 h post-administration. Danpron (0.1 mL/kg, IM) also significantly reduced cough frequency 1 h post-administration; however, this effect was not sustained at 3 h. Maropitant (1 mg/kg, IM) did not significantly reduce cough frequency. The cough induction method was effective and minimally invasive, with no adverse effects. CONCLUSION: The present study demonstrated that butorphanol has a potent and prolonged antitussive effect in an acute canine cough model, whereas Danpron shows a transient effect. These findings provide valuable insights into the comparative efficacy of commonly used antitussive drugs in dogs.

Comparison of the effects of intranasal and intramuscular midazolam-butorphanol-ketamine on intraocular pressure, tear production and sedation in New Zealand White rabbits.

OBJECTIVE: To compare the effects of intranasal (IN) and intramuscular (IM) midazolam-butorphanol-ketamine on intraocular pressure (IOP), tear production (TP) and sedation in rabbits. STUDY DESIGN: Prospective, randomized, crossover experimental study. ANIMALS: Fourteen male New Zealand White rabbits, aged 1-2 years, body mass 3.1 ± 0.8 kg (mean ± standard deviation). METHODS: Rabbits were administered midazolam (1 mg kg-1), butorphanol (1.5 mg kg-1) and ketamine (5 mg kg-1) via IN and IM routes. IOP, TP and sedation scores were assessed at 0 (before drug administration), 5, 15, 30, 45 and 60 minutes after drug administration. Heart rate (HR), respiratory rate (fR), rectal temperature (RT), noninvasive mean arterial blood pressure (MAP) and peripheral hemoglobin oxygen saturation (SpO2) were simultaneously recorded until 45 minutes after drug administration. The onset and duration of sedation and sedation scores were recorded. RESULTS: Drug delivery route had no significant impact on mean IOP (p = 0.271) or TP (p = 0.062), and there were no significant changes over time for IOP (p = 0.711) or TP (p = 0.372). Similarly, delivery route had no significant impact on HR (p = 0.747), fR (p = 0.872), RT (p = 0.379), MAP (p = 0.217) and SpO2 (p = 0.254). Sedation onset was faster with IN (3.0 ± 1.0 minutes) than with IM administration (4.9 ± 0.7 minutes) (p = 0.011), but sedation duration was significantly longer with IM (52.6 ± 7.2 minutes) than with IN delivery (30.7 ± 6.8 minutes) (p = 0.004). There was no significant difference in sedation scores between the two delivery routes at any of the recorded time points. CONCLUSIONS AND CLINICAL RELEVANCE: The combination of midazolam-butorphanol-ketamine had minimal impact on physiological and ocular variables regardless of the route of administration, whereas IN drug administration led to a shorter onset and duration of action than IM administration.

Cardiorespiratory effects of intramuscular alfaxalone combined with low-dose medetomidine and butorphanol in dogs anesthetized with sevoflurane.

Background: The intramuscular (IM) administration of 7.5-10 mg/kg of alfaxalone produces anesthetic effects that enable endotracheal intubation with mild cardiorespiratory depression in dogs. However, the effects of IM co-administration of medetomidine, butorphanol, and alfaxalone on cardiorespiratory function under inhalation anesthesia have not been studied. Aim: To assess the cardiorespiratory function following the IM co-administration of 5 µg/kg of medetomidine, 0.3 mg/kg of butorphanol, and 2.5 mg/kg of alfaxalone (MBA) in dogs anesthetized with sevoflurane. Methods: Seven intact healthy Beagles (three males and four females, aged 3-6 years old and weighing 10.0-18.1 kg) anesthetized with a predetermined minimum alveolar concentration (MAC) of sevoflurane were included in this study. The baseline cardiorespiratory variable values were recorded using the thermodilution method with a pulmonary artery catheter after stabilization for 15 minutes at 1.3 times their individual sevoflurane MAC. The cardiorespiratory variables were measured again following the IM administration of MBA. Data are expressed as median [interquartile range] and compared with the corresponding baseline values using the Friedman test and Sheff's method. A p < 0.05 was considered statistically significant. Results: The intramuscular administration of MBA transiently decreased the cardiac index [baseline: 3.46 (3.18-3.69), 5 minutes: 1.67 (1.57-1.75) l/minute/m2 : p < 0.001], respiratory frequency, and arterial pH. In contrast, it increased the systemic vascular resistance index [baseline: 5,367 (3,589-6,617), 5 minutes:10,197 (9,955-15,005) dynes second/cm5/m2 : p = 0.0092], mean pulmonary arterial pressure, and arterial partial pressure of carbon dioxide. Conclusion: The intramuscular administration of MBA in dogs anesthetized with sevoflurane transiently decreased cardiac output due to vasoconstriction. Although spontaneous breathing was maintained, MBA administration resulted in respiratory acidosis due to hypoventilation. Thus, it is important to administer MBA with caution to dogs with insufficient cardiovascular function. In addition, ventilatory support is recommended.

Protective effects of butorphanol in oleic acid-endotoxin "two-hit" induced rat lung injury by suppression of inflammation and apoptosis.

Butorphanol is widely used as an anesthetic drug, whether butorphanol could reduce organ injury and protecting lung tissue is unknown. This study explored the effects of butorphanol on ALI and investigated its underlying mechanisms. We established a "two-hit" rat model and "two-hit" cell model to prove our hypothesis. Rats were divided into four groups [control, "two-hit" (OA + LPS), "two-hit" + butorphanol (4 mg/kg and 8 mg/kg) (OA + LPS + B1 and OA + LPS + B2)]. RPMVE cells were divided into four groups [control, "two-hit" (OA + LPS), "two-hit" + butorphanol (4 µM and 8 µM) (OA + LPS + 4 µM and OA + LPS + 8 µM)]. Inflammatory injury was assessed by the histopathology and W/D ratio, inflammatory cytokines, and arterial blood gas analysis. Apoptosis was assessed by Western blotting and flow cytometry. The effect of NF-κB p65 was detected by ELISA. Butorphanol could relieve the "two-hit" induced lung injury, the expression of TNF, IL-1ß, IL-6, and improve lung ventilation. In addition, butorphanol decreased Bax and cleaved caspase-3, increased an antiapoptotic protein (Bcl-2), and inhibited the "two-hit" cell apoptosis ratio. Moreover, butorphanol suppressed NF-κB p65 activity in rat lung injury. Our research showed that butorphanol may attenuate "two-hit"-induced lung injury by regulating the activity of NF-κB p65, which may supply more evidence for ALI treatment.

Can Multimodal Analgesia Reduce Postoperative Opioid Consumption in Patients Undergoing Shoulder Arthroscopy? A Retrospective Study.

AIM: The aim of this study was to investigate whether multimodal analgesia can decrease postoperative opioid usage in patients undergoing shoulder arthroscopy. METHODS: Patients diagnosed with subacromial impingement syndrome who underwent acromioplasty at our institution between October 2022 and November 2023 were retrospectively analyzed. Patients were divided into an observation group and a control group based on postoperative pain management methods. The control group received intravenous self-controlled electronic analgesia (sufentanil injection 1 µg/kg + butorphanol injection 4 mg + 0.9% NaCl injection to 100 mL), while the observation group received multimodal analgesia (ropivacaine subacromial pump 3 mL/h, combined with oral celecoxib and acetaminophen). Visual Analog Scale (VAS) scores were recorded preoperatively and at various postoperative time points, and opioid usage, length of hospital stay, and analgesia-related complications within 1 week postoperatively were compared between groups. The 36-item Short Form Health Survey (SF-36) scores and the Constant-Murley score (CMS), were also assessed 1 day and 1 week after treatment. RESULTS: One hundred thirty-two patients were included in the study, 66 in the observation group and 66 in the control group. In the control group, there were 46 males and 20 females, with a mean age of 55.47 ± 11.42 years and in the observation group 44 males and 22 females, with a mean age of 56.13 ± 12.19 years The observation group consistently reported significantly lower pain intensity compared to the control group at 8 h (T1), 24 (T2), and 48 h (T3) after surgery (p < 0.05). Additionally, the observation group exhibited significantly lower opioid usage and complication rates compared to the control group (p < 0.05). SF-36 scores and CMS scores were significantly higher in the observation group 1 week after treatment compared to the control group (p < 0.05). CONCLUSIONS: Following shoulder arthroscopy, multimodal analgesia effectively reduces opioid consumption, lowers complication rates, and provides effective short-term pain relief. This approach carries significant implications for improving patient outcomes.

Cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry during continuous intravenous infusion of a combination solution of xylazine, butorphanol, and propofol in calves.

General anesthesia in calves is easier to perform under field conditions, total intravenous anesthesia (TIVA) than using inhalation anesthesia. In the present study, cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry were assessed during continuous infusion of a combination solution of 0.01% xylazine, 0.001% butorphanol, and 0.2% propofol (XBP) at doses of 6 (G6; 10 µg/kg/min xylazine, 1 µg/kg/min butorphanol, 200 µg/kg/min propofol) and 9 mL/kg/h (G9; 15 µg/kg/min xylazine, 1.5 µg/kg/min butorphanol 300 µg/kg/min propofol). For both groups, five castrated Holstein calves received intravenous injections of xylazine (0.2 mg/kg) and propofol (2 mg/kg), followed by a continuous infusion of XBP for 60 min to maintain anesthesia. Respiratory management consisted of tracheal intubation followed by spontaneous inhalation of pure oxygen. Cardiopulmonary, anesthesia, hematology, and blood biochemistry variables were assessed at rest (baseline) and every 5 or 15 min after the start of the XBP infusion. Quality of arousal was assessed based on the swallowing reflex recovery time from the stop of XBP infusion, and the sternal position time and standing time after atipamezole administration. XBP produced adequate sedation, analgesia, and muscle relaxation in all calves and maintained stable anesthesia for 60 min. As XBP infusion time passed, rectal temperature and heart rate became lower, and mean arterial blood pressure increased. In both groups, hematologic and blood biochemical effects were mild. The quality of arousal was not different, and all calves were standing. The results of the present study suggested that XBP is useful for TIVA in calves.

Effectiveness of Butorphanol in alleviating intra- and post-operative visceral pain following microwave ablation for hepatic tumor: a dual-central, randomized, controlled trial.

Many patients who underwent hepatic percutaneous microwave ablation (MWA) reported experiencing pain during the procedure. This study utilized a well-designed multicentral, randomized, and placebo-controlled format to investigate the effects of Butorphanol. Patients who underwent MWA were randomly assigned to either Butorphanol or normal saline group. The primary outcomes of the study were assessed by measuring the patients' intraoperative pain levels using a 10-point visual analog scale (VAS). Secondary outcomes included measuring postoperative pain levels at the 6-h mark (VAS) and evaluating comprehensive pain assessment outcomes. A total of 300 patients were divided between the control group (n = 100) and the experimental group (n = 200). Butorphanol showed statistically significant reductions in intraoperative pain levels compared to the placebo during surgery (5.00 ± 1.46 vs. 3.54 ± 1.67, P < 0.001). Significant differences were observed in postoperative pain levels at the 6-h mark and in the overall assessment of pain (1.39 + 1.21 vs. 0.65 + 0.81, P < 0.001). Butorphanol had a significant impact on reducing the heart rate of patients. The empirical evidence supports the effectiveness of Butorphanol in reducing the occurrence of visceral postoperative pain in patients undergoing microwave ablation for hepatic tumor. Furthermore, the study found no noticeable impact on circulatory and respiratory dynamics.

EFFICACY OF TOLAZOLINE AND VATINOXAN IN REDUCING ADVERSE EFFECTS OF BUTORPHANOL-AZAPERONE-MEDETOMIDINE IMMOBILIZATION IN ROCKY MOUNTAIN ELK (CERVUS CANADENSIS).

A mixture of butorphanol, azaperone, and medetomidine (BAM) is frequently used for immobilization of North American hoofstock. Common adverse effects include respiratory depression, hypoxemia, and bradycardia. In this nonblinded crossover study the efficacy of two a-2 adrenergic antagonists, tolazoline and vatinoxan, were evaluated in alleviating adverse effects of BAM in Rocky Mountain elk (Cervus canadensis). Early administration of these antagonists was hypothesized to cause an increase in heart rate, respiratory rate, partial pressure of oxygen (PaO2) and hemoglobin oxygen saturation (SpO2), as well as reduction in mean arterial blood pressure without affecting sedation levels. Eight captive adult female elk were immobilized on three separate occasions at least 14 d apart with 0.15 mg/kg butorphanol, 0.05 mg/kg azaperone, and 0.06 mg/kg medetomidine. Tolazoline (2 mg/kg IM), vatinoxan (3 mg/mg medetomidine IV) or sterile saline (2 ml IM) were administered 20 min postinduction. The BAM caused hypoxemia, bradycardia, and moderate hypertension, and because of the severe hypoxemia observed, all animals received intratracheal oxygen throughout immobilization. Heart rate, respiratory rate, rectal temperature, SpO2, PaO2, and systolic, diastolic, and mean arterial blood pressure were monitored every 5 min throughout the immobilization. Intramuscular tolazoline caused a brief but significant drop in mean arterial pressure compared with controls and a brief but nonsignificant increase in heart rate. Vatinoxan caused a significant drop in blood pressure and a brief significant increase in heart rate. Changes in respiratory rates and PaO2 were not observed with either antagonist; however, all animals received oxygen, which may have influenced this result. The depth of sedation was unchanged after administration of either drug.

RESPONSE AND PHYSIOLOGIC OUTCOMES AFTER BUTORPHANOL, MIDAZOLAM, AND MEDETOMIDINE IMMOBILIZATION AND REVERSAL IN CAPTIVE REINDEER (RANGIFER TARANDUS).

Sedation, recovery response, and physiologic outcomes were evaluated in five captive reindeer (Rangifer tarandus) in Minnesota using a completely reversible immobilization protocol. Reindeer were immobilized with butorphanol (0.23-0.32 mg/kg), midazolam (0.23-0.32 mg/kg), and medetomidine (0.15 mg/kg) (BMM) via IM dart. Induction time (IT), recumbency time (DT), and recovery time (RT) were recorded. Temperature (T), respiratory rate (RR), pulse rate (PR), pulse oximetry (SpO2), arterial blood gas values including oxygen (PaO2), and carbon dioxide (PaCO2) tensions and lactate (Lac) were recorded preoxygen supplementation and 15 min postoxygen supplementation. Reversal was done using naltrexone (2.3-3.0 mg/kg), flumazenil (0.008-0.01 mg/kg) and atipamezole (0.62-0.78 mg/kg) (NFA) IM, limiting recumbency to 1 h. Median IT, DT, and RT were 5 min, 46 min, and 7 min, respectively. SpO2 (92 to 99%, P = 0.125), PaO2 (45.5 to 97 mmHg, P = 0.25), and PaCO2 (46.5 to 54.6 mmHg, P = 0.25) all increased, whereas Lac (3.02 to 1.93 mmol/L, P = 0.25) decreased between baseline and 15 min postoxygen supplementation, without statistical significance. BMM immobilization, and reversal with NFA provided rapid and effective immobilization and recovery, respectively. Oxygen supplementation mitigated hypoxemia in all reindeer.

The effects of selected sedatives on basal and stimulated serum cortisol concentrations in healthy dogs.

Background: Hormone assessment is typically recommended for awake, unsedated dogs. However, one of the most commonly asked questions from veterinary practitioners to the endocrinology laboratory is how sedation impacts cortisol concentrations and the adrenocorticotropic hormone (ACTH) stimulation test. Butorphanol, dexmedetomidine, and trazodone are common sedatives for dogs, but their impact on the hypothalamic-pituitary-adrenal axis (HPA) is unknown. The objective of this study was to evaluate the effects of butorphanol, dexmedetomidine, and trazodone on serum cortisol concentrations. Methods: Twelve healthy beagles were included in a prospective, randomized, four-period crossover design study with a 7-day washout. ACTH stimulation test results were determined after saline (0.5 mL IV), butorphanol (0.3 mg/kg IV), dexmedetomidine (4 µg/kg IV), and trazodone (3-5 mg/kg PO) administration. Results: Compared to saline, butorphanol increased basal (median 11.75 µg/dL (range 2.50-23.00) (324.13 nmol/L; range 68.97-634.48) vs 1.27 µg/dL (0.74-2.10) (35.03 nmol/L; 20.41-57.93); P < 0.0001) and post-ACTH cortisol concentrations (17.05 µg/dL (12.40-26.00) (470.34 nmol/L; 342.07-717.24) vs 13.75 µg/dL (10.00-18.90) (379.31 nmol/L; 275.96-521.38); P ≤ 0.0001). Dexmedetomidine and trazodone did not significantly affect basal (1.55 µg/dL (range 0.75-1.55) (42.76 nmol/L; 20.69-42.76); P = 0.33 and 0.79 µg/dL (range 0.69-1.89) (21.79 nmol/L; 19.03-52.14); P = 0.13, respectively, vs saline 1.27 (0.74-2.10) (35.03 nmol/L; 20.41-57.93)) or post-ACTH cortisol concentrations (14.35 µg/dL (range 10.70-18.00) (395.86 nmol/L; 295.17-496.55); (P = 0.98 and 12.90 µg/dL (range 8.94-17.40) (355.86 nmol/L; 246.62-480); P = 0.65), respectively, vs saline 13.75 µg/dL (10.00-18.60) (379.31 nmol/L; 275.86-513.10). Conclusion: Butorphanol administration should be avoided prior to ACTH stimulation testing in dogs. Further evaluation of dexmedetomidine and trazodone's effects on adrenocortical hormone testing in dogs suspected of HPA derangements is warranted to confirm they do not impact clinical diagnosis.

Effects of Butorphanol on Respiration in White Rhinoceros (Ceratotherium simum) Immobilized with Etorphine-Azaperone.

This article reports on respiratory function in white rhinoceros (Ceratotherium simum) immobilized with etorphine-azaperone and the changes induced by butorphanol administration as part of a multifaceted crossover study that also investigated the effects of etorphine or etorphine-butorphanol treatments. Six male white rhinoceros underwent two immobilizations by using 1) etorphine-azaperone and 2) etorphine-azaperone-butorphanol. Starting 10 min after recumbency, arterial blood gases, limb muscle tremors, expired minute ventilation, and respiratory rate were evaluated at 5-min intervals for 25 min. Alveolar to arterial oxygen gradient, expected respiratory minute volume, oxygen consumption, and carbon dioxide production were calculated. Etorphine-azaperone administration resulted in hypoxemia and hypercapnia, with increases in alveolar to arterial oxygen gradient, oxygen consumption, and carbon dioxide production, and a decrease in expired minute ventilation. Muscle tremors were also observed. Intravenous butorphanol administration in etorphine-azaperone-immobilized white rhinoceros resulted in less hypoxemia and hypercapnia; a decrease in oxygen consumption, carbon dioxide production, and expired minute ventilation; and no change in the alveolar to arterial oxygen gradient and rate of breathing. We show that the immobilization of white rhinoceros with etorphine-azaperone results in hypoxemia and hypercapnia and that the subsequent intravenous administration of butorphanol improves both arterial blood oxygen and carbon dioxide partial pressures.

Validation of the anesthetic effect of a mixture of remimazolam, medetomidine, and butorphanol in three mouse strains.

Proper administration of anesthesia is indispensable for the ethical treatment of lab animals in biomedical research. Therefore, selecting an effective anesthesia protocol is pivotal for the design and success of experiments. Hence, continuous development and refinement of anesthetic agents are imperative to improve research outcomes and elevate animal welfare. "Balanced anesthesia" involves using multiple drugs to optimize efficacy while minimizing side effects. The medetomidine, midazolam, and butorphanol, called MMB, and medetomidine, alfaxalone, and butorphanol, called MAB, are popular in Japan. However, the drawbacks of midazolam, including its extended recovery time, and the narrow safety margin of MAB, have prompted research for suitable alternatives. This study replaced midazolam in the MMB combination with remimazolam (RMZ), which is noted for its ultra-short half-life. The resulting combination, called MRB, was effective in providing a wider safety margin compared to MAB while maintaining an anesthesia depth equivalent level to that of MMB in mice. Notably, MRB consistently exhibited better recovery scores after antagonist administration in contrast to MMB. Furthermore, the re-sedation phenomenon observed with MMB was not observed with MRB. The rapid metabolism of RMZ enables reliable anesthesia induction, circumventing the complications linked to MAB. Overall, MRB excelled in providing extended surgical anesthesia and swift post-antagonist recovery. These results highlight the potential of RMZ for broader animal research applications.

Butorphanol inhibits androgen biosynthesis and metabolism in rat immature Leydig cells in vitro.

Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. The objective of this study was to investigate the influence of butorphanol on androgen secretion by rat Leydig cells isolated from the 35-day-old male rats. Rat Leydig cells were cultured with 0.5-50 µM butorphanol for 3 h in vitro. Butorphanol at 5 and 50 µM significantly inhibited androgen secretion in immature Leydig cells. At 50 µM, butorphanol also blocked the effects of luteinizing hormone (LH) and 8bromo-cAMP-stimulated androgen secretion and 22R-hydroxycholesterol- and pregnenolone-mediated androgen production. Further analysis of the results showed that butorphanol downregulated the expression of genes involved in androgen production, including Lhcgr (LH receptor), Cyp11a1 (cholesterol side-chain cleavage enzyme), Srd5a1 (5α-reductase 1), and Akr1c14 (3α-hydroxysteroid dehydrogenase). Additionally, butorphanol directly inhibited HSD3B1 (3ß-hydroxysteroid dehydrogenase 1) and SRD5A1 activity. In conclusion, butorphanol may have side effects of inhibiting androgen biosynthesis and metabolism in Leydig cells.

Butorphanol-Azaperone-Medetomidine Is as Safe and Effective as Nalbuphine-Azaperone-Medetomidine for Immobilization of Juvenile American Black Bears (Ursus americanus).

Immobilization kits including butorphanol-azaperone-medetomidine (BAM) and nalbuphine-azaperone-medetomidine can provide effective, safe, and easy-to-use protocols in bears. Nalbuphine-azaperone-medetomidine is not commercially available but may be useful for wildlife agencies because it does not contain controlled substances. This study directly compared BAM to nalbuphine-azaperone-medetomidine immobilization in 10 juvenile healthy black bears (10 mo old; four females, six males) undergoing prerelease examinations after rehabilitation. Bears were immobilized via remote delivery of 1 mL of BAM (n=5) or nalbuphine-azaperone-medetomidine (n=5) intramuscularly in the shoulder during December (randomized, blinded trial). Bears were intubated, monitored with an electrocardiogram, pulse oximeter, capnograph, noninvasive blood pressure cuff, and rectal thermometer, and underwent physical examination, sample collection, morphometrics, and ear-tag placement. Induction, physiologic, and recovery parameters were recorded, including arterial blood gas analysis. The anesthetic agents were antagonized with atipamezole and naltrexone. There were no differences between protocols in induction or recovery times. There were no differences between protocols in heart rate, respiratory rate, temperature, oxygen saturation, end-tidal CO2, mean arterial pressure, or blood gas analysis or any differences between male and female bears in any parameters. Bears were hypertensive and normoxemic with low oxygen saturation via pulse oximeter, but all recovered smoothly and were released within 2 h of recovery. This study supports that nalbuphine-azaperone-medetomidine is clini-cally as safe and effective as BAM in American black bears.

Comparing the Efficacy of Two Immobilization Drug Combinations for the Chemical Restraint of Bobcats (Lynx rufus).

Chemical immobilization agents that provide rapid induction time, short duration of action, wide margin of safety, and postreversal recovery are important attributes to the handling process of immobilized animals. We evaluated differences in induction, recovery, and physiologic parameters in 23 (13 female, nine adults and four yearlings; 10 male, nine adults and one yearling) free-ranging bobcats (Lynx rufus) chemically immobilized with an intramuscular combination of ketamine (10 mg/kg) and xylazine (KX; 1.5 mg/kg; n=11) or a combination of butorphanol (0.8 mg/kg), azaperone (0.27 mg/kg), and medetomidine (BAM; 0.32 mg/kg; n=12). Induction parameters, time to first effect, hemoglobin oxygen saturation, and anesthesia between bobcats administered KX and BAM were similar. Pulse rate was significantly higher for KX than for BAM. Time to standing and full recovery after reversal were faster for bobcats administered BAM than KX. Six of 11 (55%) bobcats given KX were effectively immobilized with a single injection, and five required additional drugs to allow adequate time for processing. Of 12 bobcats given BAM, six (50%) were effectively immobilized with a single injection, three (25%) individuals were not completely immobilized and required additional doses to allow adequate time for processing, and three (25%) required additional doses after complete arousal during processing. We found that BAM provided reduced sedation and processing times (<30 min), whereas KX provided extended sedation and processing times beyond 30 min. We suggest that researchers increase initial BAM drug volumes for yearling and adult bobcats at time of processing and consider taking appropriate safety precautions when handling free-ranging bobcats.