***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: Four studies of a relatively small size, involving 144 participants, were included in this review. A combination of ranitidine with diphenhydramine was more effective at improving the resolution of urticaria than diphenhydramine administered alone (risk ratio (RR) 1.59, 95% confidence interval (CI) 1.07 to 2.36). Although there was a similar improvement in itching, weal size, and intensity, cimetidine provided no statistically significant greater overall improvement in symptoms of urticaria when compared to diphenhydramine. However, a combination of these medications was more effective than diphenhydramine alone (RR 2.02, 95% CI 1.03 to 3.94). Adverse events were reported with several of the interventions, i.e. ranitidine and diphenhydramine, causing drowsiness and sedation, but there was no significant difference in the level of sedation from baseline with either famotidine or diphenhydramine. The very limited evidence provided by this review was based on a few old studies of a relatively small size, which we categorised as having high to unclear risk of bias. Thus, at present, the review does not allow confident decision-making about the use of H2-receptor antagonists for urticaria. Although some of these studies have reported a measure of relief of symptoms of urticaria and rather minimal clinical improvement in some of the participants, the evidence was weak and unreliable. We have emphasised the lack of precision and limitations in the reported data where appropriate in this review.
Output:

There are a range of treatment options for urticaria, of which the most well-known are the H1-antihistamines. This review evaluated the efficacy and safety of a similar category, the H2-antihistamines, and included 4 low-quality studies, which examined 144 participants. No firm conclusions could be drawn, but the combination of ranitidine with diphenhydramine appeared to be slightly more effective in reducing the symptoms of urticaria than diphenhydramine alone. In one study, cimetidine appeared to be as effective as diphenhydramine. However, the combination of both drugs was more effective than diphenhydramine alone. Drowsiness and sedation were reported with diphenhydramine, but there was no significant difference in the level of sedation with either famotidine or diphenhydramine. The studies were rather old and considered very few outcomes that were of importance to people with urticaria. Therefore, there is currently insufficient evidence to indicate whether this type of medication is effective or not.