Efficacy and safety of butorphanol nasal spray for the relief of postepisiotomy pain

Abstract

Butorphanol tartrate, a synthetically derived opioid agonist-antagonist analgesic was evaluated for postepisiotomy pain relief when administered as a nasal spray. In this double-blind, parallel-group, dose-response study, 150 women with moderate to severe episiotomy pain were randomly assigned to receive a single dose of transnasal butorphanol (0.25, 0.5, 1, or 2 mg) or placebo. Pain relief was evaluated for 6 hours. The 2-mg dose of butorphanol was associated with a rapid onset of analgesia and a greater efficacy than placebo, as determined by using several markers including pain intensity differences, pain relief, pain half gone, sum of pain intensity differences, sum of pain relief, observer global assessment, and the time to remedication. As a result of the high placebo response, the 0.25-mg, 0.5-mg, and 1-mg doses did not differ significantly from placebo. The drug was well tolerated, with somnolence and dizziness the most frequently reported side effects. These were dose related.