We therefore organized a double-blind comparative study on the effect of maximal doses of inhaled formoterol, comparing theni with equivalent doses of salbutamol in patients with stable asthma. The investigation was approved by the Medical Ethical Committee on the De Wever Hospital.
Materials and Methods
The aim of the study was to compare the maximal bronchodilator effect of very high doses of inhaled formoterol and salbutamol in patients with stable reversible asthma. Furthermore, the influence on serum potassium concentrations, pulse rate, and ECG was assessed for both drugs.
The maximal dose of the fi-mimetic was defined as that dose that had already been taken at the time when (1) the FEV, had increased to 10 percent above the normal predicted value, or (2) there was an increase of no more than 5 percent in the FEV, after the last two doses, or (3) the last drug dose was not well tolerated, the pulse rate exceeded 140*min or the ECG showed flattening of the T waves, or (4) when the patient felt unwell, for example, as a result of tremor, shivering, or agitation.
The study was double-blind, single-center, and within patient. Patients of either sex between 18 and 70 years with reversible asthma who had been in a clinically stable phase for at least seven days before they started the study were allowed to participate.