No abstract

Assessment on admission and responses to treatment were studied in 20 patients aged 65 years or over admitted with severe acute exacerbations of asthma and were compared with patients aged 40 years or less who were managed similarly. The elderly asthmatic had less marked tachycardia and pulsus paradoxus compared to the younger group for similar degrees of airways obstruction and arterial blood gas abnormalities. Assessment confined to physical examination would, therefore, have underestimated the severity of their asthma. The rates of improvement in airflow obstruction were similar in both young and old but those elderly patients who had required maintenance oral corticosteroids were less likely to reach their predicted peak expiratory flow rate (PEFR) than their peers or younger patients.

No abstract

The efficacy of ketotifen, a tricyclic benzocycloheptathiophene derivative, was assessed in an outpatient clinical trial and in a group of 12 asthmatic subjects with exerciseinduced asthma. Subjects in the outpatient trial had mild asthma and consisted of two groups: a group of 24 atopic asthmatics with at least one positive skin test reaction and with an associated history of bronchial reactivity to at least one allergen; and a group of eight asthmatics with one or more positive skin prick tests but no bronchial reactivity to an allergen. Both groups took four weeks medication of ketotifen 1 mg bd and placebo in a randomised double-blind crossover study. There was no difference between ketotifen and placebo for any measurement made during the study and consequently no evidence of drug efficacy. The exercise study followed a standardised protocol and each subject took in random double-blind order, placebo, 1 mg, 2 mg, and 4 mg ketotifen two hours before exercise. There was no difference in the mean decreases in lung function from pre-exercise baseline values after three doses of ketotifen than with placebo. Drug levels suggested ketotifen was well absorbed. It would appear that if given for a period of only four weeks ketotifen has no beneficial effects in the management of mild asthma, and that a single dose before exercise does not modify exercise-induced asthma.Ketotifen, an orally active tricyclic benzocycloheptathiophene derivative, has several properties suggesting it might be useful in the management of asthma.' 2 It inhibits passive cutaneous anaphylaxis and has a mast cell stabilising effect. It is also a potent antihistamine specific for Hi receptors with little anticholinergic activity and it raises intracellular cyclic-AMP levels by inhibiting phosphodiesterase.' 2 Ketotifen has been shown to be effective in preventing histamine-induced bronchospasm,34 aspirin and tartrazine-induced asthma,5 and as effective as disodium cromoglycate in controlling allergen-induced bronchospasm.3 Proof of its efficacy in preventing exercise-induced bronchospasm is confined to a single comparative study with cromoglycate which showed good protection in eight of 11 subjects.3 Controlled trials assessing the value of ketotifen as prophylaxis for asthma in outpatients have given inconclusive results. It has been shown to be as effective as disodium

No abstract