Plasma levels and therapeutic response: the relevance to community pharmacy.

An assessment of 26 patients, taking theophylline for COAD or asthma, was undertaken in a Belfast Community pharmacy. Patients had peak flow rate and serum theophylline concentration monitored. Based on these findings patients were counselled and, where appropriate, theophylline dosage was adjusted using a pharmacokinetic computer program. A statistically significant improvement was found between the number of patients who had a serum theophylline concentration in the therapeutic range at the initial assessment and at 3 months and 12 months. This was accompanied by a statistically significant improvement in peak expiratory flow rates.