Theophylline products are not interchangeable and should be prescribed by BRAND NAME.
Remember narrow therapeutic window and potential for interactions.
The half-life is increased (giving higher theophylline levels) in heart failure,cirrhosis
and viral infections, in the elderly and by drugs as cimetidine,ciprofloxacin,
erythromycin, fluvoxamine, diltiazem, verapamil and oral contraceptives. Vomiting
may indicate a toxic dose.
The half-life is decreased (giving lower theophylline levels) in smokers, in
chronic alcoholism and by drugs as phenytoin, carbamazepine, rifampicine
To avoid excessive dosage in obese patients , dose should be calculated in
the basis of ideal body weight.
Plasma-theophylline concentration should be available to guide dosing of
iv aminophylline in patients taking oral theophylline or aminophylline.