Pirbuterol vs. hydroxyzine vs. theophylline vs. placebo in the treatment of bronchial asthma.

Pirbuterol (10mg and 15mg capsules) was found to be an effective bronchodilator on large and small airways in bronchial asthm. Benefit occurred within one hour and it lasted five or more hours. It had no significant effect on ECG, blood pressure or heart rate. Mild nervousness and/or muscle tremor occurred occasionally. Hydroxyzine usually prevented these side effects.