Phloroglucinol as an adjuvant analgesic to treat renal colic

PurposeWe tested whether the addition of phloroglucinol to piroxicam could improve pain relief in patients with acute renal colic visiting the emergency department.Materials and MethodsPatients with a diagnosis of acute renal colic were prospectively randomized to receive intravenous phloroglucinol (200 mg) or placebo combined with intramuscular piroxicam (20 mg). We monitored the visual analogic scale (VAS), heart rate, arterial blood pressure, need for rescue therapy, and adverse events at different time points for 1 hour. We recorded admission requirement and new visit at 72 hours for renal colic. The primary end point was to assess pain relief at 1 hour, defined as a decrease of 50% or more as compared with the initial VAS. The secondary objectives were to compare the 2 groups for VAS at any time points, the need for rescue therapy, and the occurrence of adverse events.ResultsOf the 309 eligible patients, 253 entered the study. A total of 126 patients received phloroglucinol and 127 patients received placebo. Pain relief at 1 hour was obtained in 89 patients (71%) receiving phloroglucinol and 89 patients (70%) receiving placebo (P = .89). There were no differences in VAS between the 2 groups at any time points. Rescue therapy was required in 37 patients (29%) receiving phloroglucinol and 38 patients (30%) receiving placebo (P = .51). Number of adverse events was similar with phloroglucinol and placebo: 20 (16%) and 16 (13%), respectively (P = .44).ConclusionsThere was no evidence that the addition of phloroglucinol improved the efficiency of piroxicam to relieve pain in acute renal colic.