Microcrystalline theophylline: the relation between oral dose saliva levels, and peak expiratory flow rates in asthma

Summary

In a double-blind, placebo-controlled study, three groups of adult asthmatic patients with reversible airways obstruction received microcrystalline theophylline in a dosage of 500 mg, 750 mg or 1000 mg daily, in divided doses, over 3 to 5 days. Saliva concentrations of theophylline were correlated with changes in peak expiratory flow rate (PEFR). The results showed there was no significant improvement in PEFR over placebo values in either the 500 mg or 750 mg groups and only at two time points in the 1000 mg group. The 1000 mg dosage study had to be abandoned because of toxic effects. The absence of response was possibly related to the clinical features of the patients studied.

Key Words::

• Theophylline
• asthma
• saliva