To determine whether the cotreatment with histamine H1 antagonists (H1) and histamine H2 antagonists (H2) are effective in treating chronic urticaria sufferers whose condition does not improve by H1 antagonist alone, we investigated academic books, papers provided by pharmaceutical companies and the MEDLINE on-line data base. No sufficient information could be found from inquiries of books and company-provided papers. However, from the MEDLINE data base, six papers on clinical trials based on the protocols of randomized controlled on trial were obtained and used as evidence. We also performed a meta-analysis based on the findings of the 6 papers.
It is thus considered indispensable for drug information services to find appropriate papers using a data base search and then provide such information to doctors together with a critical appraisal by pharmacists.
