Well-established studies have shown repeatedly that effective analgesia enhances locomotion, increases appetite, and reduces the time of postoperative recovery for humans, rodents, rabbits, which are particularly sensitive to pain and inflammation, and other species. As a general rule, for maximal effectiveness, analgesics should be first administered before the animal is fully recovered from anesthesia and should be continued for the next 48-72 hours. However, as little as a single post-operative dose, in many circumstances, is sufficient to dramatically and positively influence recovery. Mechanism of Action.
Analgesics can act through several mechanisms.
Nonsteroidal Anti-Inflammatory Drugs. Because of different sites of action, these agents are synergistic with opioids. It is very effective when combined with opioids or buprenorphine and has a 24-48 hour duration of efficacy in most species. For the control of acute or chronic visceral pain, opioids are the most powerful and effective analgesics. Bradycardia, respiratory depression, excessive sedation, nausea, ileus and pica may be side effects.