Moracizine Theophylline

MORACIZINE BRONCHODILATORS -THEOPHYLLINE 1 plasma concentrations of theophylline and risk of therapeutic failure Due to induction of microsomal enzyme activity May need to t dose of theophylline by 25%... 

Moracizine is an enzyme inducer it increases the rate of clearance of theophylline (12). 

Moracizine modestly increases theophylline clearance, although conversely animal data suggest that moracizine inhibits theophylline metabolism. 

Single oral doses of aminophylline and a sustained-release theophylline preparation (TheoDur) were given to 12 healthy subjeets. After they took moracizine 250 mg three times daily for 2 weeks, the AUC of theophylline was reduced by 32% and 36%, its clearance was increased by 44% and 66%, and the elimination half-life decreased by 33% and 20%, for aminophylline and theophylline respectively. ... 

Uncertain. Moracizine is an enzyme inducer and appears to increase the metabolism of theophylline. In contrast, in vitro and animal data show moracizine to be an inhibitor of the cytochrome P450 isoenzyme CYP1A2, which is the main isoenzyme involved in the metabolism of theophylline. This would, in theory, be expected to lead to raised theophylline levels. 

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