Complex sentence: Some recommend that opioids and barbiturates not be used due to questionable efficacy and the risk of rebound headache, but others identify butorphanol as a useful analgesic for acute migraine.
Split into simpler sentences: Some recommend that opioids and barbiturates not be used due to questionable efficacy and the risk of rebound headache. Others identify butorphanol as a useful analgesic for acute migraine.