Viloxazine Theophylline

Several drugs, for example the oral contraceptive pill, viloxazine, thiabendazole, aminoglutethimide, antiepileptics (carbamazepine, phenytoin, barbiturates) and the antibiotic rifampicin decrease plasma concentrations of theophylline. 

Viloxazine increases serum theophylline levels and toxicity may occur. 

It is suggested that the viloxazine competitively antagonises the metabolism of the theophylline by the liver, thereby reducing its clearance and resulting in an increase in its serum levels. 

Information seems to be limited to these reports but it would appear to be a elinieally important interaetion. Theophylline serum levels should be well monitored if viloxazine is added, anticipating the need to reduee the dosage. 

Perault MC, Griesemann E, Bouquet S, Lavoisy J, Vandel B. A stucfy of tiie interaction of viloxazine with theophylline. TherDmgMonit( 9%9) 11,520-2. 

Laaban JP, Dupeyron JP, Lafay M, Sofeir M, Rochemaure J, Fabiani P. Theophylline intoxication following viloxazine induced decrease in clearance. EurJ Clin Pharmacol (1986) 30,... 

---