Which semisynthetic opioid is about 10 times stronger than morphine and is used in dogs for restraint and diagnostic procedures, often with a tranquilizer to produce neuroleptanalgesia?

• A. Sevoflurane
• B. Oxymorphone
• C. Fentanyl
• D. Epinephrine

Answer: (B)

Oxymorphone is a semisynthetic opioid derived from morphine with about tenfold greater analgesic potency. In dogs it’s commonly used to facilitate restraint and diagnostic procedures because it provides reliable analgesia and sedation. When given with a tranquilizer, it produces neuroleptanalgesia, a state where sedation and analgesia together minimize responses to handling and procedures. This combination allows quick, painful or uncomfortable exams to be performed more safely and comfortably. Oxymorphone often causes less histamine release than morphine, contributing to smoother recoveries, though it still requires careful monitoring for respiratory depression and cardiovascular effects. Sevoflurane is an inhalant anesthetic, epinephrine is a vasopressor, and fentanyl, while potent, is far more than ten times morphine in strength, not the specific 10× potency described here.