Role of butorphanol in preemptive analgesia: A comparison with pentazocine
Abstract
Background: Preemptive analgesia establishes effective antinociception before surgery and continuation of this effective analgesic level well into the postoperative period. Butorphanol tartrate and pentazocine lactate are opioid analgesics with mixed agonist-antagonist properties.
Aim: The aim of the present study was to compare the preemptive analgesic effect of butorphanol and pentazocine given by intramuscular (IM) route as a primary outcome. Secondary outcome was to compare hemodynamic parameters and the side effects profile.
Methodology: A comparative randomized, single blind, and prospective clinical study in sixty patients ASA physical status I and II was carried out. Patients were demographically similar. Patients were randomized to receive either a butorphanol injection (Group B) 2 mg (n=30) or pentazocine injection (Group P) 60 mg (n=30) both IM 60 min before surgery. Lower abdominal surgeries under spinal anesthesia were selected. Duration of pain relief was recorded by visual analogue scale (VAS) postoperatively up to 24 h. Sedation was measured with Cook’s sedation score system. Patients were observed for any change in vital signs and any other side effect for 24 h. Rescue analgesia in the form of IM diclofenac sodium 75 mg was given when VAS≥3.
Results: Duration of analgesia was up to 18 h in Group P while it was extended in Group B, but this was statistically not significant. Requirements of rescue analgesia were higher and occurred earlier in Group P, although not statistically significant. Sedation score was also comparable. Hemodynamic changes were not significant with the exception of an increase in mean arterial pressure in Group P. No severe side effects were observed in any patient of either group.
Conclusion: Butorphanol a mixed agonist-antagonist opioid in the dose of 2 mg IM is an acceptable alternative to pentazocine as a pre-emptive analgesic due to longer duration of analgesia and greater analgesic efficacy with low incidence of side effects.
