Intravenous theophylline after beta 2-agonist treatment in severe acute asthma. Effect on patients who are not pre-treated with theophylline.

The effect of i.v. theophylline after high-dose beta 2-agonist treatment in severe acute asthma was studied in 30 patients from a multicentre study who reported not having taken theophylline during the last 24 hours. One hour after the start of inhaled or i.v. salbutamol treatment, all patients received 6 mg/kg of i.v. theophylline. The plasma concentration 30 minutes after the start of the theophylline infusion was 78 +/- 13 mumol/l (mean +/- SD). The mean change (delta) in peak expiratory flow (PEF) was 8 +/- 6% of the predicted 30 minutes after the theophylline infusion and 7 +/- 5% 60 minutes after it. The increase in PEF was greater in this patient group than in a group of 101 patients from the same multicentre study who were on theophylline medication and were therefore given a reduced dose (3 mg/kg) (7 +/- 5 vs. 4 +/- 6% of the predicted value, p < 0.01). The proportion of patients with an increase in PEF of > or = 10% of the predicted at discharge was 27% (8/30) in the patient group in this investigation and 14% (14/101) in the group who was on theophylline treatment.