Benefits of flavonoid and metronidazole use after excisional hemorrhoidectomy: a randomized double-blind clinical trial

Background: Excisional hemorrhoidectomy remains the most effective treatment for a significant group of patients with hemorrhoids, despite the potential for postoperative pain. The purpose of this study was to evaluate the effects of flavonoid and metronidazole use in the postoperative period on patients undergoing excisional hemorrhoidectomy.

Methods: A double-blind randomized clinical study was performed. Sixty-eight patients underwent excisional hemorrhoidectomy and were randomized into 4 groups of 17 patients each to receive double-placebo (G1), metronidazole plus placebo (G2), flavonoids plus placebo (G3) or metronidazole plus flavonoids (G4) in the postoperative period. A standard analgesic protocol was offered equally for all groups. Postoperative pain, bleeding, edema, pruritus and tenesmus were evaluated during the following three periods: from immediately after the operation until postoperative day (POD)7, from POD 8 to POD 14, and from POD 15 to POD 30. The patients were required to complete symptom questionnaires and to attend postoperative follow-up on PODs 7, 14 and 30. The effect of each drug was assessed for each symptom, and the groups were compared with each other and over time.

Results: There was less severe pain in all postoperative periods in the groups using flavonoids (G3 and G4, both p < 0.0001), with an observed synergistic effect of flavonoids combined with metronidazole during the first 14 days after surgery (p < 0.0001). Flavonoid use was also associated with decreased bleeding (G3, p = 0.031 and G4, p = 0.016) between the first and second postoperative weeks CONCLUSIONS: The use of flavonoids alone and in combination with metronidazole resulted in a reduction of most symptoms, particularly pain, after excisional hemorrhoidectomy.

Trial registration: The present study was registered in the SISNEP (document CAAE-0035.0.240.000-11), after approval by the research ethics committee (CEP) of the Hospital Felício Rocho (protocol nº393 / 11).