Asthma sufferers who regularly take one of the beta-2 agonists may be building up a resistance to the more powerful and newer drugs used to ease an acute attack.
Researchers from the University of Dundee tested users of the beta-2 agonist salmeterol against a group receiving a placebo to discover which was the more sensitive to the drug salbutamol, used to relieve acute bronchoconstriction.
They discovered a marked difference in response between the two groups, indicating that salmeterol users who, in the test, were taking it twice a day might need an increased dose of salbutamol if it is going to be effective.
This latest research puts another question mark over continual use of beta-2 agonists. Some in medicine are worried about the adverse reactions to the drug, while others suspect that it might work against the new family of drugs suspicions that this research has vindicated (The Lancet, July 22, 1995).