The efficacy of oral theophylline and the combination of theophylline + hydroxyzine in chronic bronchial asthma.

The efficacy of 265 mg theophylline (150 mg of the theophylline being slow-release) and the combination of 265 mg theophylline + 7.5 mg hydroxyzine hydrochloride were compared in a double-blind cross-over placebo-controlled study in 12 patients with chronic reversible bronchial asthma. The patients took their drugs at 7.00 a.m., 1.00 p.m. and 7.00 p.m. 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 p.m. The frequency and severity of symptoms and side-effects as well as the auxiliary use of isoprenaline inhalations were also recorded. The trial involved three three-day periods. Both oral theophylline and the combination of theophylline + hydroxyzine caused significant improvements in PEF in all measurement times. The PEF-level was higher when the combination was used than with plain theophylline, though the difference was not significant. Only the combination of theophylline + hydroxyzine had a significant effect on the symptoms, and the use of additional isoprenaline inhalations was also reduced during the combination period. Side-effects were minimal. Circadian variation of bronchial obstruction was seen in all these patients.