The Effect of Theophylline in Patients With Allergic Rhinitis
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 28
- 试验地点
- 1
- 主要终点
- Difference in total nasal symptom score
研究概览
简要总结
Allergic rhinitis and asthma are common respiratory diseases, which often coexist. The prevalence of allergic rhinitis in subjects with asthma is up to 80%, and the prevalence of asthma is 3-5 times greater in subjects with rhinitis than healthy controls. The mechanisms of the allergen response in both diseases are parallel to each other, with similar mediator and cellular responses to similar allergens. These observations have led to the suggestion that both diseases are different expressions of one airway disease.We wish to evaluate the effect of low dose theophylline in patients with asthma, given its effects as subtherapeutic concentrations and the propensity to develop adverse events at higher doses.
详细描述
The disease modifying treatments for asthma and rhinitis mirror each other. The first line therapy being the topical corticosteroids, for which there is good evidence of superiority over other therapies. They work by altering the transcription of genes involved in the inflammatory process, thereby favourably influencing the synthesis of inflammatory proteins and cytokines. They have been shown to reduce the numbers of inflammatory cells and their inflammatory action. Other disease modifying therapies such as anti-IgE antibodies improve allergic symptoms in both asthma and rhinitis. Theophylline has been used for many years as a treatment for asthma but has not been used to help patients with rhinitis.
Theophylline has been considered a weak bronchodilator for many years. However relatively recently, it was shown to have anti-inflammatory effects in patients with asthma. It reduces eosinophil counts and eosinophilic cationic protein (ECP) concentration in induced sputum of asthmatic patients. The combination of low dose theophylline has greater effects on lung function and asthma severity than high dose inhaled corticosteroids.
Aubier el al have shown, using a nasal allergen challenge model of rhinitis, that 3 weeks treatment with slow release oral theophylline reduced the increase in the concentration of eosinophilic cationic protein (ECP) and the percentage of eosinophils in nasal lavage following the challenge. Furthermore there was a significant reduction in nasal symptoms in those patients treated with theophylline. However theophylline has not previously been evaluated as a therapeutic option in patients with chronic rhinitis in the clinic setting.
Cigarette smoking is a major cause of morbidity in patients with asthma and has been shown to be independently associated with impaired quality of life in asthmatic children. Recent evidence suggests that patients with asthma who smoke are relatively resistant to inhaled or oral corticosteroid therapy, with larger doses being required for clinical benefit. The actual mechanism for this observation is unknown however one hypothesis is that smoking has an effect on histone deacetylase. It is known that theophylline can active histone deacetylase and therefore improve the efficacy of corticosteroids.
Theophylline causes significant adverse effects at high doses. Unfortunately the bronchodilator effect occurs at doses very close to those causing adverse effects. This low therapeutic index for bronchodilation means that therapeutic monitoring is required. However the anti-inflammatory effect of theophylline and the effect of theophylline on histone deacetylase activity occurs at concentrations lower therapeutic level for bronchodilation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 16 Years 至 65 Years（Child, Adult, Older Adult）
- 接受健康志愿者
- 否
入选标准
- •Males or females, aged between 16 and 65 years.
- •Weight between 50 and 150 Kg.
- •Smokers, non-smokers or ex-smoker.
- •Chronic rhinosinusitis as defined as 2 or more symptoms of nasal blockage/congestion, discharge, facial pain or reduction in smell for more than 12 weeks.
- •A positive skin prick test or RAST to a perennial allergen
- •Patients with a seasonal component to their symptoms can be enrolled out with the relevant pollen season.
- •Patients must be receiving intranasal corticosteroids
- •Patients will be permitted to receive inhaled short and long acting beta2 agonists or anti-cholinergic drugs, inhaled corticosteroids (up to a dose of 2mg per day BPD equivalent), oral montelukast or oral antihistamines.
- •Able to provide written informed consent.
排除标准
- •Significant medical, surgical or psychiatric disease that would affect the results of the study in the opinion of the investigator.
- •Women who are pregnant or breast feeding
- •Patients with previous cardiac problems or significant renal or hepatic impairment
- •Upper respiratory tract infection in the last month as defined by yellow or green nasal discharge and increase in the usual nasal symptoms.
- •Patients consuming more than the recommended amount of alcohol (14 units per week for women and 21 units per week for men) Inhaled corticosteroids at a dose greater than 2mg beclomethasone dipropionate (BDP) equivalent or oral corticosteroids or oral zafirlukast
- •Currently receiving oral theophyllines.
- •Previous adverse effects to oral or intravenous theophylline.
- •Currently any medication known to interact with theophylline including
- •Allopurinol
- •Macrolide, quinolone or isoniazid
- •Fluvoxamine
- •Carbamazepine, phenytoin
- •Fluconazole or itraconazole
- •Barbiturates
- •Oestrogens
- •Cimetidine
研究组 & 干预措施
200mg theophylline
200mg twice daily of slow release theophylline
干预措施: Theophylline (Intervention Group) (Drug)
Placebo
200mg twice daily of placebo drug
干预措施: Placebo (Placebo Group) (Drug)
结局指标
主要结局
Difference in total nasal symptom score
时间窗: 18 weeks
The primary endpoint will be the difference in total nasal symptom score between active and placebo treatment periods measured at the clinic
次要结局
- The difference in domiciliary average total nasal symptom score(18 weeks)
- The difference in nasal peak inspiratory flow at clinic visit(18 weeks)
- The difference in domiciliary nasal peak inspiratory flow(18 weeks)
- The difference in Sino-Nasal Outcomes Test (SNOT) -22 questionnaire(18 weeks)
- Secondary Analysis(18 weeks)
- Serum theophylline concentration at the end of both placebo or active treatment periods.(18 weeks)
- Serum urea and electrolyte concentration at the both placebo or active treatment periods(18 weeks)
- Drug related adverse effects(18 weeks)
- The difference histone deacetylase activity from epithelial cells obtained from nasal scrapings.(18 weeks)