A randomized controlled trial of rectal versus intramuscular diclofenac for post-operative analgesia after open myomectomy

Abstract

AimTo determine the efficacy and safety of rectal versus intramuscularly administered Diclofenac in reducing post-operative pain in the first 24 h after open-myomectomy. MethodsA single blind, placebo controlled randomized trial consisting of 90 consenting women that had open-abdominal-myomectomy. They were randomized into two-groups (rectal-group and intramuscular-group) of 45 women (1:1 ratio). Rectal-group received 75 mg of Diclofenac suppository 12 hourly for 24 h and placebo (3 ml of intramuscular injection-water) 12hourly for 24 h while intramuscular-group received intramuscular Diclofenac 75 mg 12 hourly for 24 h and placebo (Anusol suppository) 12 hourly for 24 h. Both groups received intramuscular Pentazocine 30 mg 6 hourly for 24 h as primary analgesic after myomectomy. Pain was assessed using a Ten-Point Visual-Analogue-Scale. Participants’ satisfaction of the mode of the pain relief was assessed using the Likert-scale after 24 h. The primary outcome was the pain score using the visual-analogue-scale. The secondary outcome-measures were participants’ satisfaction after 24 h of administration of the drugs, the need and frequency of rescue-analgesia and maternal-side-effects. ResultThe baseline socio-demographic characteristics were similar in both groups. There was no statistically significant difference between both groups in pain assessment at 1 h post-myomectomy (p-value > 0.05). However, the pain assessments at 6, 12, 18 and 24 h post-myomectomy were statistically significant with more pain in intramuscular-group when compared to rectal-group. Majority of participants in rectal-group were both very satisfied (35.6 %) and satisfied (55.6 %) when compared to intramuscular-group (11.1 %) and (31,1%) respectively (p-value < 0.05). Also majority of the participants in intramuscular-group were dissatisfied (17.8 %) with none of the participant showing any form of dissatisfaction (p-value < 0.05). Majority of the participant in rectal-group had no drug side effects when compared with intramuscular-group. Epigastric discomfort was commoner in rectal-group while drowsiness was commoner in intramuscular-group. ConclusionRectal Diclofenac with intramuscular Pentazocine is significantly associated with better effectiveness in pain reduction and maternal satisfaction when compared with intramuscular Diclofenac and intramuscular Pentazocine following open-myomectomy. While epigastric discomfort was the commonest side-effect in rectal-group, drowsiness was commoner in intramuscular-group. Trial RegistrationPan-African-clinical-trial-registry (PACTR); PACTR202206556144219.