Comparison of salbutamol and ephedrine in oral bronchodilator combinations with theophylline and hydroxyzine: their effects on asthmatics.

The efficacies of three antiasthamatic bronchodilator combinations were compared using data obtained from sixteen patients. During the trial the patients measured their peak expiratory flow (PEF) every day at 7.00 a.m., 10.00 a.m. and 9.30 pm. Six patients also measured their PEF at 1.30 a.m. The frequency and severity of symptoms and side-effects as well as the auxiliary use of isoprenaline inhalations were also recorded. This double-blind cross-over trial consisted of five four-day periods including three periods with different drug combinations and two placebo periods. By increasing the sympathomimetic activity of the basic oral drug combination of theophylline and hydroxyzine with salbutamol or ephedrine the therapeutic effect of the combination was also increased although not statistically significantly. All combinations tested differed significantly from placebo in their effect. Harmful side-effects increased in proportion to the potency of the sympathomimetic drug used in the combination; they were minimal during treatment with the basic theophylline-hydroxyzine combination. Circadian variation of bronchial obstruction was a constant phenomenon in all asthmatics participating in this trial.