Diurnal variation in the pharmacokinetics of intravenous theophylline and etophylline in healthy subjects

Diurnal variation in CYP1A2 enzyme activity in South Asians and Europeans

“…The drug metabolising enzyme cytochrome P450 1A2 (CYP1A2) contributes to the metabolism of a number of commonly used medicines including clozapine, olanzapine and theophylline . Diurnal variation in the pharmacokinetics of intravenously administered theophylline, which is a drug predominantly metabolised by CYP1A2, has been reported, with higher concentrations observed in the morning . Similarly, the theophylline prodrug aminophylline (also a CYP1A2 substrate) was found to have significant pharmacokinetic changes related to time of administration .…”

A simple and rapid HPLC/UV method for the simultaneous quantification of theophylline and etofylline in human plasma

“…Unlike other xanthine derivatives, etofylline does not convert into theophylline in the body. Etofylline is mainly excreted unchanged by the kidneys and only a small fraction of it is metabolized by hydroxylation [6]. This offers a wide therapeutic window and combination of etofylline and theophylline (Deriphylline ® ) exhibits less frequent adverse side effects than an equivalent dose of theophylline alone.…”

Formulation development and evaluation of sustained release matrix tablets of Theophylline and Etophylline and study of polymers effect on dissolution rate

“…Unlike other xanthine derivatives, etofylline does not convert into theophylline in the body. Etofylline is mainly excreted unchanged by the kidneys and only a small fraction of it is metabolized by hydroxylation (Chauhan et al, 1986). This offers a wide therapeutic window and combination of etofylline and theophylline exhibits less frequent adverse side effects than an equivalent dose of theophylline alone.…”