Combination of H1 and H2 Receptor Antagonists in Treatment of Asthmatic Patients


1 Department of Internal Medicine, Islamic Azad University of Mashad

2 Epidemiology and Biostatistics Division, NRITLD, Shaheed Beheshti University of Medical Sciences and Health Services, MASHAD-IRAN.


Introduction: It is believed that H1 histamine receptor blocker does not have any beneficial effect on treatment of asthma, but combination of H1 and H2 receptor antagonists has a good effect on chronic resistant urticaria. Since the pathogenesis of asthma and urticaria are similar, we expected that this combination might have some benefits in treatment of asthma. Materials and Methods: In this study, we selected 66 patients with known diagnosis of asthma in acute exacerbation of their disease. The patients did not have any history of smoking, GERD, postnasal discharge and rhinorrhea, but experienced symptoms such as cough, dyspnea, and wheezing. All patients underwent spirometry (Spirosift 3000 Fukuda Denshi), and those who had obstructive pattern and improved FEV1 more than 20% after using bronchodilator were randomly entered either the case or control groups after signing the consent. Spirometry parameters were VC, FVC, FEV1, FEV1/FVC, PEF, FEF 25-75%, MEF25%, and MEF 50%. Phase 1: Case group treated with 0.5 mg/kg prednisolone and salbutamol orally plus terfenadine (bid) and Ranitidine (tid), for one week. Phase 2: Case group treated with salbutamol and beclomethasone spray with antihistamines as mentioned, for two weeks. Phase 3: Same as phase two for one month. Spirometry was done at the end of each phase. In control group since exclusion of corticosteroid and bronchodilator from treatment was dangerous, management was similar to the case group. The only exception was the omission of antihistamines. Statistical analysis: Chi-square was used for interpretation of qualitative variables. F statistics and Kruskal Wallis tests as well as paired t- test were used for comparison of changes in spirometry findings. Results: 66 patients finished first and second phases and 24 patients went through the third phase. M/F ratio was 2/3, median age was 33 years in both groups (range10-70 yrs.). Comparison of symptoms between case and control groups showed that in study group during second phase, cough improved more than control group. Otherwise, there were no significant differences in symptoms and signs of the two groups. During all three phases, spirometry measurement showed no significant difference between study and control group, except for MEF25% that improved in study group more than control group in the second phase. Conclusion: Corticosteroids and β-2 agonists are very potent and effective drugs in treatment of asthma. Addition of H1 and H2 histamine receptor antagonists to standard therapy of asthma has minimal effect but in case of troublesome cough that is not relieved with that treatment, addition of antihistamines may be beneficial. (Tanaffos2004; 3(12): 57-62)