[Susceptibility of the spanish population to adverse effects by sulfasalazine: systematic review].

BACKGROUND Clinical experience raises suspicion that the spanish population could suffer higher rates of side effects of sulfasalazine (SSZ) therapy. We conducted a systematic review of existing literature to analyze the susceptibility to developing adverse events produced by SSZ in the Spanish population. MATERIAL AND METHOD A literature search was conducted in EMBASE, IBECS, and MEDLINE from 1973 to March 2007. The items sought were those describing adverse effects, both in text and tables, and reasons for withdrawal, the population under study and discussion of differences in side effects of the different treatment groups. RESULTS Of the 106 retrieved articles, 36 were selected for review and detailed analysis. 34 articles were selected from MEDLINE and EMBASE and 2 from IBECS. We did not find any study that showed that the Spanish population was more susceptible to SSZ. CONCLUSIONS The adverse effects of SSZ vary with the pattern of acetylation. Thus, in slow-acetylators, depending on the dosage of SSZ, the side effects increase significantly. In the Spanish population slow-acetylators prevalence is higher than in other ethnic groups. Therefore, one could infer that the incidence of adverse side effects by SSZ could be higher in the Spanish population than in others different ethnic groups. We found no evidence that the Spanish population was more likely to suffer adverse effects by SSZ than other ethnic groups.