Comparison of IV salbutamol with IV aminophylline in severe acute asthma.

Correspondence Comparison of IV salbutamol with IV aminophylline in severe acute asthma Sir, In a double-blind comparative study of children with acute asthma, Hambleton and Stone (Archives, 1979, 54, 391) showed that IV salbutamol and aminophylline were equally effective when given during the first 24 hours. The optimal use of theophylline requires a dosage regimen that maintains the serum concentration within the therapeutic range of 10-20 mg/l (Jenne et al., 1972; Weinberger and Bronsky, 1974). Hambleton and Stone used a loading dose of 4 mg/kg followed by 0-6 mg/kg per hour. In a recent study (Selvig et al., 1979), despite a bigger loading dose of 5 mg/kg in slightly older children (aged 8-15 years), therapeutic values were reached in only 62% of them and maximum serum concentration in each case was in the lower half of the range. A more suitable loading dose would have been 7.5 mg/kg, which is tolerated by most children, with average serum concentrations in the middle of the range (Weinberger, 1978). Furthermore, the infusion rate of 0-6 mg/kg per hour is much lower than the 0-85 mg/kg per hour recommended to maintain therapeutic serum concentrations in children less than 9 years (Hendeles and Weinberger, 1979). The similar clinical effect shown by Hambleton and Stone when aminophylline dosage was subtherapeutic suggests to us that a different conclusion might have been reached had a therapeutic dose ofaminophylline been used. Bjerve, K. S. (1979). Serum concentrations of theophylline in children following the administration of doses generally recommended: new dosage regimen required. Drs Hambleton and Stone comment: We note the criticism about the dose of aminophylline and make the following comments. The assertion that therapeutic efficacy will be achieved when serum theo-phylline is 10-20 mg/I is based on the use of oral theophylline compounds in the prophylaxis of perennial asthma (Jenne et al., 1972; Weinberger and Bronsky, 1974). Weinberger et al. (1976) gave data on acute asthma in children and evaluated the dosages necessary to maintain the above level. However, their paper did not indicate how effective their regimen was in terms of producing relief from asthma. Turner-Warwick (1957) studied acute wheezing in adults, and judged the appropriate serum levels simply from reports from patients on the subjective relief of symptoms after oral theophylline compounds. Selvig et al. (1979) studied serum theo-phylline levels after a single IV dose of aminophylline, and recommended a loading dose of 6 mg/kg but …