Pharmacokinetics of buprenorphine following intravenous and intramuscular administration in male rhesus macaques (Macaca mulatta)

This study reports the pharmacokinetics of buprenorphine in conscious rhesus macaques (Macaca mulatta) after intravenous (i.v.) and intramuscular (i.m.) administration. Four healthy, opioid‐naïve, socially housed, adult male macaques were used. Buprenorphine (0.03 mg/kg) was administered intravenously as a bolus or intramuscularly on separate occasions. Blood samples were collected prior to, and up to 24 h, postadministration. Serum buprenorphine concentrations were analyzed with liquid chromatography–mass spectrometry. Noncompartmental pharmacokinetic analysis was performed with commercially available software. Mean residence time in the i.v. study as compared to the i.m. study was 177 (159–189) vs. 185 (174–214) min, respectively [median (range)]. In the i.v. study, concentration back‐extrapolated to time zero was found to be 33.0 (16.8–57.0) ng/mL [median (range)]. On the other hand, the maximum serum concentration found in the i.m. study was 11.8 (6.30–14.8) ng/mL [median (range)]. Rhesus macaques maintained concentrations >0.10 ng/mL for over 24 h in the i.v. study and over 12 h in the i.m. study. Bioavailability was found to be 68.1 (59.3–71.2)% [median (range)]. No significant adverse effects were observed in the monkeys at the 0.03 mg/kg dose of buprenorphine during either study.     

The diagnosis and treatment of periorbital sarcoid in the horse: 445 cases from 1974 to 1999

OBJECTIVE: Diagnosis and management of periorbital sarcoids in horses is a significant clinical challenge for the practicing veterinary surgeon and pathologist. The purpose of this study was to investigate the response of various types of sarcoids to different therapeutic methods. Animals studied Medical records of 445 clinical patients. Procedures This paper retrospectively examines the clinical and histological features of periorbital sarcoids and the treatment of 445 cases. Treatment by surgical excision, cryosurgery, Bacillus-Calmette-Gaérin (BCG) immunomodulation, topical cytotoxic applications, and radiation are described. RESULTS: Six types of sarcoid can be found in the immediate periorbital region and each has some characteristics of other disorders of the skin with which they can be confused. The diagnosis of sarcoids is, however, relatively simple in most cases. The lesions are not necessarily restricted to the dermis and epidermis, but commonly invade into the subcutis and the deeper muscular structures around the eye. Treatment with radiation is expensive and difficult to manage but resulted in the best outcome with almost 100% resolution in 66 cases. By contrast, surgical excision has serious potential complications that arise primarily as a result of the infiltrative nature of periorbital sarcoids. The value of BCG immunomodulation therapy for fibroblastic and nodular lesions described by previous workers is confirmed in this paper, with a good overall response (69%), provided that the material was injected intralesionally. Perilesional injection did not appear to carry a significant benefit. However, treatment of verrucose or occult lesions by this method gave generally poor results. The results of intralesional injection of cisplatin emulsions suggest that this may be an effective method of treatment in cases where other modalities are not feasible. In common with previous reports, failure to resolve the lesions frequently resulted in regrowth of the tumor, and in most cases this recurrence appeared to be more aggressive, with extensive local infiltration and faster growth. Conclusion The periorbital tissues are less tolerant of damage than those at many other sites and therefore certain treatment methods may be contraindicated. This suggests that it is important to select the best possible treatment at the first opportunity. It is a wise precaution to warn owners of horses with periorbital sarcoids of the dangers of leaving them and the particular risks associated with the currently available treatments.     

Clinical course of renal adenocarcinoma associated with hypercupraemia in a horse

A four-year-old shire mare with haematuria, colic, terminal weight loss and an abdominal mass had a large unilateral renal adenocarcinoma. Clinical signs were monitored for 11 months. Increased serum copper concentrations were measured on two occasions. Hypercupraemia is discussed as a possible paraneoplastic change.