Effects of theophylline withdrawal in well-controlled asthmatics treated with inhaled corticosteroid

Bifunctional Drugs for the Treatment of Respiratory Diseases

Over the last decade, there has been a steady increase in the use of fixed dose combinations for the treatment of a range of diseases, including cancer, AIDS, tuberculosis and other infectious diseases. It is now evident that patients with asthma or chronic obstructive pulmonary disease (COPD) can also benefit from the use of fixed dose combinations, including combinations of a long-acting β₂-agonist (LABA) and an inhaled corticosteroid (ICS), and combinations of LABAs and long-acting muscarinic receptor antagonists (LAMAs). There are now also "triple inhaler" fixed dose combinations (containing a LABA, LAMA and ICS) under development and already being made available in clinical practice, with the first such triple combination having been approved in India. The use of combinations containing drugs with complementary pharmacological actions in the treatment of patients with asthma or COPD has led to the discovery and development of drugs having two different primary pharmacological actions in the same molecule that we have called "bifunctional drugs". In this review we have discussed the state of the art of bifunctional drugs that can be categorized as bifunctional bronchodilators, bifunctional bronchodilator/anti-inflammatory drugs, bifunctional anti-inflammatory drugs and bifunctional mucolytic and anti-inflammatory drugs.

Addition to inhaled corticosteroids of leukotriene receptor antagonists versus theophylline for symptomatic asthma: a meta-analysis

BACKGROUND

Inhaled corticosteroids (ICSs) are widely used in combination with second controller medications in the management of asthma in adults and children. There lacks a systematic comparison between addition of leukotriene receptor antagonists (LTRAs) and theophylline to ICS. The purpose of this meta-analysis was to evaluate the difference of the efficacy and safety profile of adding either LTRAs or theophylline to ICS in adults and children with symptomatic asthma.

METHODS

Randomised controlled trials (RCTs) published prior to November 2014 were acquired through systematically searching and selected based on the established inclusion criteria for publications. The data extracted from the included studies were further analyzed by a meta-analysis.

RESULTS

We included eight RCTs, of which six recruited adults and two recruited children aged 5 to 14 years. The primary outcomes were changes in lung function from baseline, including forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). Overall, addition of LTRAs led to significantly better morning PEF {mean difference (MD) 16.94 [95% confidence interval (CI): 11.49-22.39] L/min, P<0.01} and FEV1 [MD 0.09 (95% CI: 0.03-0.15) L, P=0.005] as compared to addition of theophylline. There were no differences between the two treatments in terms of evening PEF, adverse events, rescue medication use and asthma exacerbation.

CONCLUSIONS

The combination of LTRA and ICS leads to modestly greater improvement in lung function than the combination of theophylline and ICS in the treatment of symptomatic asthma. Long-term trials are required to assess the efficacy and safety of these two therapies.

Long-term observations of the clinical course after step down of corticosteroid inhalation therapy in adult chronic asthmatics: correlation with serum levels of eosinophil cationic protein

BACKGROUND

Symptoms often deteriorate in well-controlled asthmatics after a step down in inhaled beclomethasone dipropionate (iBDP) therapy if the serum concentration of eosinophil cationic protein (sECP) is high. This deterioration is significantly abrogated by pranlukast, a leukotriene receptor antagonist, or by seratrodast, a thromboxane A2 receptor antagonist. However, these results were based on short-term (less than 6 months) observations.

METHODS

We studied 35 well-controlled adult asthmatics. We assigned the patients into different groups according to their sECP levels before the step down: (i) group A, sECP < 25 microg/L; (ii) group B, sECP > or = 25 microg/L; and (iii) group C, sECP > or = 25 microg/L but patients treated with pranlukast or seratrodast. We began the study with a step down in iBDP therapy (initial step down), then followed the clinical course of the asthma for 2 years. During the study period, we decreased, increased or maintained the iBDP dose on the basis of the stepwise approach described in the National Institutes of Health guidelines. We monitored the time and frequency of exacerbation and evaluated the iBDP dose required to control the asthma symptoms.

RESULTS

The rates of exacerbation after the step down were high in groups A and B. In group A, the conditions were again qualified for the step down in all patients, but this was not the case for most group B patients. From 15 to 21 months after the initial step down, the average dose of iBDP required to control symptoms was significantly higher in group B than in group A patients (P = 0.0127-0.0373). The exacerbation rate in group C after 12 months tended to be lower than in the other two patient groups (P = 0.0743). In group C, the average dose of iBDP from 9 to 24 months after the initial step down was significantly lower than before the step down (P < 0.0001) and was not significantly different from the mean dose of iBDP in groups A or B.

CONCLUSIONS

High sECP in well-controlled asthma may indicate the necessity for a higher iBDP dose over a long period than when the sECP concentration is not high. Even if sECP is high, pranlukast or seratrodast help to prevent exacerbation of asthma and enable successful step down in iBDP therapy for at least 2 years thereafter.