An evaluation of theophylline dosing. Suggested by the Saudi national protocol for children with severe Asthma

OBJECTIVE: To evaluate the impact of Saudi national protocol on the diagnosis and management of asthma for optimizing theophylline use in children with severe asthma. To also review theophylline clearance and provide guidelines for individualization of doses.

METHODS: Theophylline level was estimated in blood samples of 66 children with severe asthma who were admitted to King Abdulaziz University Hospital during the period 1998-1999. The theophylline doses given to these patients was reviewed and patients were categorized into 2 groups: Group one had received doses recommended by Saudi national protocol ± 10%, group 2 had received doses <90% of that recommended by Saudi national protocol. The distribution of theophylline levels in blood samples of each group was estimated. Theophylline steady state level was used to estimate theophylline clearance using a standard pharmacokinetic equation.

RESULTS: Out of the total samples from group one, 70% of theophylline levels were within therapeutic range, while only 10% of the total samples of group 2 were within therapeutic range. The mean theophylline clearance in children (1-8 years) was estimated as 0.092 ± 0.023 and was found significantly higher than the mean theophylline clearance (0.069 ± 0.014) which is observed in older children (9-13 years).

CONCLUSION: Saudi national protocol theophylline dose guidelines had a favorable impact on the optimization of theophylline use in children with severe asthma. Guidelines that ensure accurate adjustment of doses on individual basis in view of drug level were suggested.