New Drugs: Respiratory and allergic disease--I

Only a few new drugs have been introduced in the treatment of respiratory disease since this subject was last reviewed in this journal.' 2 The present review is not comprehensive but will highlight some of the important therapeutic aspects of respiratory medicine that have emerged recently.In addition to newly intro- duced drugs drugs of potential future value will also be discussed.Part I of this review will cover asthma and allergic rhinitis; part II will review new treatments in chronic obstructive airways disease, antibiotics, and the chemotherapy of tuberculosis. AsthmaOver the past 10 years there has been an increase in both morbidity and mortality from asthma.3'Despite the fact that the current trend in deaths from asthma coincides with increasing sales of all classes of drugs for treating asthma7 it has been suggested that those who die of asthma have not received optimal treatment.8Too much reliance may have been placed on 13 adrenoceptor agonists, resulting in the development of tachyphylaxis to such drugs and of possible dangerous arrhythmias,9'0 but there is no convincing evidence to support this view.It is important to realise that inflammatory changes in the airways of asthmatics may underlie the bronchial hyperreactivity and clinical symptoms of asthma."Drugs that prevent or suppress inflammation of the airways have been advocated as a prophylaxis against attacks of asthma.'2In two recent reports the bronchial hyperresponsiveness of mild asthma in children and adults was reduced by regular treatment with inhaled steroids but was worsened, if anything, by regular treatment with inhaled 12 agonists.1 ' 14 These studies raise the important and as yet unresolved issue of whether the strategy for anti-asthma treatment should consist of regular prophylactic treatment, with 12 agonists being used only for acute relief of wheezing and dyspnoea.An important development over the past five years has been improved delivery of anti-asthma drugs, such as spacer devices to increase deposition of inhaled aerosols and the development of controlled release theophylline preparations.Nedocromil sodium, a mast cell "stabiliser" and anti-inflammatory agent, has been recently introduced as an asthma prophylactic.A xanthine derivative, enprofylline, that has a wider margin of safety between therapeutic and toxic effects and has potentially fewer side effects than theophylline is currently being clinically evaluated but is not yet on the market.