Citalopram 4- Theophylline

Beta agonists (terbutaline, albuterol) Theophylline Antidepressants Bupropion Citalopram Escitalopram Duloxetine Fluoxetine Fluvoxamine... 

FLUVOXAMINE BRONCHODILATORS- THEOPHYLLINE Possible t plasma concentrations of theophylline Fluvoxamine is potent inhibitor of CYP1A2, and fluoxetine is less potent as an inhibitor. Paroxetine, sertraline, escitalopram and citalopram are not currently known to cause any inhibition Consider an alternative antidepressant... 

Theophylline serum levels can be markedly and rapidly increased by fluvoxamine. Toxicity will develop if the theophylline dosage is not suitably reduced. Some preliminary clinical evidence su ests that fluoxetine and citalopram may not interact, and in vitro evidence su ests that paroxetine and sertraline are also unlikely to interact... 

In a study in 13 healthy subjects citalopram 40 mg daily for 21 days (to achieve steady-state) did not affect the pharmacokinetics of a single 300-mg oral dose of theophylline. ... 

In vitro studies with human liver microsomes have shown that fluvoxam-ine inhibits the eytoehrome P450 isoenzyme CYP1A2, the principal enzyme responsible for the metabolism of theophylline. This results in raised theophylline levels and toxieity. This metabolic function, and hence interaction, appears to be severely reduced in patients with severe cirrhosis, probably due to redueed hepatie expression of CYP1A2 and reduced uptake of fluvoxamine. The other SSBIs, citalopram, fluoxetine, paroxetine and sertraline only weakly inhibited CYP1A2 in vitro, and consequently would not be expeeted to interact. ... 

Moller SE, Larsen F, Pitsiu M, Rolan PE. Effect of citalopram on plasma levels of oral theophylline. Clin Ther(2000) 22, 1494-1501. 

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