Butorphanol

Synopsis: Butorphanol tartrate1,2 is a totally synthetic strong analgesic with both narcotic agonist and antagonist properties. When 1 or a few doses of butorphanol and other strong analgesic drugs such as morphine, pethidine or pentazocine were administered to patients with acute (in most cases postoperative) pain in a series of comparative studies, the analgesia produced was usually comparable in all aspects. Studies of analgesic efficacy and safety in patients with acute myocardial infarct pain have not been done. Only a small number of patients with chronic pain have received repeated doses of butorphanol over extended periods, and its relative efficacy, safety and tolerability when used in this manner needs further investigation. In other areas of use, 1 or 2 doses of butorphanol (1 or 2mg) were at least as effective and safe as 40 or 80mg of pethidine when used to relieve pain during active labour, but further studies utilising neurobehavioural evaluations of the newborns for several days should be undertaken to confirm the apparent lack of adverse effects on the infant. In a few well designed anaesthesia studies butorphanol appeared to be comparable to morphine or pethidine when used as a pre- anaesthetic medication or as a component of ‘balanced’ anaesthesia.