In the PRE Group, which consisted of seventeen studies, a reduction in the incidence of nausea and vomiting in patients treated with gabapentin was observed in two studies while an increase in nausea and vomiting was reported in one study.
Among the total number of PONV episodes, there was a reduction in the episodes of nausea per patient in the GDT group (0.7 ± 0.2 vs. 0.15 ± 0.1; P = 0.02; data expressed as mean (± SD)).
Based on the CSR, to detect a 30% reduction in relative risk of nausea 19 with 90% power, a total of 712 participants (n=356 per group) at an α of 0.05 (for a superiority test of two independent proportions) 24 is needed.
However, there is report where fentanyl addition do not cause any change in the sedation [ 10], however, similar to the findings of Randalls et. al (1991) [ 10] we found significant reduction in the incidence of nausea by the addition of fentanyl to bupivacaine.
The side effects of rizatriptan can include fatigue, somnolence, head and neck pressure, nonspecific dizziness, and nausea, and thus might have been expected to increase subjective units of discomfort despite its benefit for reduction of motion sickness.
There was a median nausea reduction of 75% for either treatment after four hours.
In both studies, the efficacy of octreotide was statistically greater in all the parameters of response (reduction in digestive hypersecretion and control of nausea and vomiting).
The above study can be concluded as bupivacaine -fentanyl combination leads to abolishment of the visceral pain, reduction in nausea incidence increased hemodynamic stability and increases the duration of post-operative analgesia; however no effect can be seen on bradycardia, nausea, vomiting, shivering, maternal or neonatal respiration.
64 Additional pharmacodynamic and clinical data suggest methylnaltrexone has potential effects on gastric emptying, on relief of nausea and vomiting, and on reduction of episodes of airway aspiration.
