The effect of premedication with butorphanol or methadone on the ease of duodenal intubation

In adult dogs undergoing upper gastrointestinal (GI) endoscopy, does premedication with butorphanol compared to premedication with methadone make duodenal intubation easier?

Treatment.

Two prospective, randomised, blinded, clinical trials.

Weak.

The evidence from the two studies is contradictory. One reports that premedication with butorphanol is associated with significantly quicker and easier duodenal intubation compared to methadone. The other reports that methadone is non-inferior to butorphanol for ease of duodenal intubation and did not identify a significant difference in speed or ease of duodenal intubation between premedications. Direct comparison of the studies is limited by differing anaesthetic protocols and variation between the scoring systems for ease of intubation.

There is insufficient evidence to support the use of butorphanol over methadone as a premedication in dogs undergoing upper GI endoscopy requiring duodenal intubation. The process of duodenal intubation may be quicker and easier with butorphanol versus methadone, but duodenal intubation can be successful with both opioids, and there is no difference in the requirement for rescue analgesia between the two drugs.