Topical Metronidazole can Reduce Pain after Surgery and Pain on Defecation in Postoperative Hemorrhoidectomy

Background Topical metronidazole (10 percent) has been previously demonstrated to decrease postoperative pain after hemorrhoidectomy. The aim of this study was to evaluate the effect of topical metronidazole (10 percent) in reducing postoperative and after-defecation pain of hemorrhoidectomy. Materials and Methods A double-blind, randomized trial was conducted to compare posthemorrhoidectomy pain with use of topical metronidazole (10 percent) vs. placebo carrier, applied to surgical site. Forty-seven patients were randomly allocated to receive metronidazole (n = 25) or placebo (n = 22). Pain was assessed using a visual analog scale preoperatively and on postoperative hours 6 and 12 and at days 1, 2, 7, and 14. The use of narcotic, additional analgesics, and complications were recorded. (Pain scores were calculated and compared with baseline values and control group (t test, SPSS ver.10). Results Patients in the topical metronidazole group had significantly less postoperative pain than those in the placebo group up to day 14 (P ≤ 0.04). There was no significant difference in narcotic analgesic requirements between groups, except on hour 12 (P < 0.05). In the metronidazole group, after-defecation pain was ranked significantly lower at day 2 (P = 0.016) and patients required fewer additional analgesics postoperatively on days 2 and 7 (P ≤ 0.04). Conclusion These finding indicate that topical 10 percent metronidazole significantly reduce posthemorrhoidectomy discomfort, and postoperative defecation pain is reduced compared with that of the placebo control group. Support: A grant of vice-chancellor for research of Mazandaran University of Medical Sciences     

Dextromethorphan metabolic phenotyping in an Iranian population

Objective CYP2D6 polymorphism of drug metabolism represents an important source of interindividual and interethnic variation in drug response. Since this polymorphism has not been studied in an Iranian population, the present study was undertaken.Methods Two hundred healthy unrelated Iranian subjects participated in this study. Phenotyping was based on high-performance liquid chromatography determination of the dextromethorphan/total dextrorphan molar ratios as metabolic ratios (MRs) in plasma samples collected at 3 h after oral administration of 30 mg dextromethorphan hydrobromide. Since the dextromethorphan detection limit of 5 ng/ml achieved in the simultaneous assay for dextromethorphan and its metabolites was not adequate to identify intermediate metabolizers (IMs), 80 of 200 samples selected randomly were also assayed using a modified, more sensitive procedure with a dextromethorphan detection limit of 1 ng/ml.Results Poor and extensive metabolizers (EMs) could be identified distinctly. A 520-fold interindividual variation in dextromethorphan MRs was observed in this study. In contrast to undetectable dextrorphan and hydroxymorphinan concentrations, clearly determinable dextromethorphan concentrations higher than10 ng/ml were observed in plasma samples of poor metabolizers (PMs). Considering the antimode of 0.3, five (2.5%, 95% confidence interval of 0.34–4.66) volunteers were identified as PMs. Using the more sensitive method, dextromethorphan was quantified in 4 (one PM) of 80 samples. Excluding the PM, a Shapiro-Wilk test indicated a non-normal distribution of MRs (P<0.01) in the latter population.Conclusions From this study it can be concluded that the frequency of PMs in an Iranian population is 2.5% (95% confidence interval of 0.34–4.66). IMs could be identified using dextromethorphan plasma assays with detection limits of at least 1 ng/ml. However, the phenotype–genotype relationships in this respect remain to be established.