Anesthesia & Clinical Research
Open Access

Abstract

The Effect of Pre-operative Oral Clonidine or Gabapentin on Post-operative Pain intensity, Morphine Consumption and Post-operative Nausea and Vomiting in Patients Who Undergone Thyroidectomy: A Double-blind Placebo-control Study

Seyed Mojtaba Marashi, Ali Akbar Morabi, Mohammad Hossein Ghafari, Omid Azimaraghi and Ali Movafegh

Background: This prospective, randomized, double-blind study evaluated the effect of clonidine and gabapentin premedication on postoperative pain intensity, morphine consumption, nausea and vomiting. Methods: Sixty-six ASA I-II patients, aged 20 to 55 were randomly allocated to orally receive either clonidine 0.2 mg (group C,n=22), placebo (group P,n=22) or gabapentin 900 mg (group G, n=22) two hours before operation. Postoperative visual analog scale for pain (VAS), nausea and vomiting were measured in the recovery room and 2,6,12 and 24 hours following the surgery as well. Results: The patients’ characteristics were alike in three groups. The VAS pain scores at measured times were significantly lower in the clonidine (3.4 ± 0.9, 4.2 ± 0.75, 4.8 ± 1.0, 4.9 ± 1.3, 3.3 ± 0.6) and gabapentin groups (3.1 ± 0.6, 4.1 ± 1.0, 3.6 ± 0.7, 4.7 ± 0.8, 3.5 ± 0.7) than in the placebo group (5.1 ± 1.6; 6.5 ± 1.5; 5.9 ± 0.9; 5.5 ± 0.8, 3.5 ± 0.7, (repeated-measures ANOVA, between-subjects effects, P<0.001) The post-operative morphine consumption in gabapentin group (18.3 ± 15.6 mg) was significantly less than clonidine (47.1 ± 29.1 mg, P=0.02) and placebo groups (65.7 ± 31.1mg, P<0.001). The incidence of PONV in the first 24 hour after surgery was significantly more in clonidine (40.9%) than gabapentin (9.1%%) and placebo (9.1%%) groups (P<0.01). Conclusion: Oral premedication with gabapentin or clonidine significantly decreases the post-operative pain and morphine consumption, without any decrease in PONV.