A comparison of the effects of hydromorphone HCl and a novel extended release hydromorphone on arterial blood gas values in conscious healthy dogs

Pharmacokinetics and pharmacodynamics of hydromorphone hydrochloride in healthy horses

OBJECTIVES

To determine the physiologic and behavioral effects and pharmacokinetic profile of hydromorphone administered intravenously (IV) to horses.

STUDY DESIGN

Prospective, randomized, crossover study.

ANIMALS

A group of six adult healthy horses weighing 585.2 ± 58.7 kg.

METHODS

Each horse was administered IV hydromorphone (0.025 mg kg^-1; treatment H0.025), hydromorphone (0.05 mg kg^-1; treatment H0.05) or 0.9% saline in random order with a 7 day washout period. For each treatment, physiologic, hematologic, abdominal borborygmi scores and behavioral data were recorded over 5 hours and fecal output was totaled over 24 hours. Data were analyzed using repeated measures anova with significance at p < 0.05. Blood samples were collected in treatment H0.05 for quantification of plasma hydromorphone and hydromorphone-3-glucuronide and subsequent pharmacokinetic parameter calculation.

RESULTS

Hydromorphone administration resulted in a dose-dependent increase in heart rate (HR) and systolic arterial pressure (SAP). HR and SAP were 59 ± 17 beats minute^-1 and 230 ± 27 mmHg, respectively, in treatment H0.05 at 5 minutes after administration. No clinically relevant changes in respiratory rate, arterial gases or temperature were observed. The borborygmi scores in both hydromorphone treatments were lower than baseline values for 2 hours. Fecal output did not differ among treatments and no evidence of abdominal discomfort was observed. Recorded behaviors did not differ among treatments. For hydromorphone, mean ± standard deviation for volume of distribution at steady state, total systemic clearance and area under the curve until the last measured concentration were 1.00 ± 0.29 L kg^-1, 106 ± 21 mL minute^-1 kg^-1 and 8.0 ± 1.5 ng hour mL^-1, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Hydromorphone administered IV to healthy horses increased HR and SAP, decreased abdominal borborygmi and did not affect fecal output.

Nanomedicine and veterinary science: the reality and the practicality

Nanomedicine is a rapidly expanding field with a promising future that is already permeating veterinary science. This review summarises the current applications for nanoparticles in human medicine and explores their potential applicability for veterinary use. The principles underlying the use of nanoparticles in drug delivery, imaging and as vaccine adjuvants are explored along with the unique issues surrounding nanoparticle toxicity and regulatory approval. A brief overview of the properties of different nanoparticle systems including, liposomes, micelles, emulsions and inorganic nanoparticles, is provided, along with a description of their current and potential future applications in veterinary medicine.