May interfere GI absorption w/ antacids containing Ca, Mg, or Al, sucralfate, didanosine, metal cations eg, Fe, multivit prep w/ Zn. Additive effect on QT interval prolongation w/ class IA (eg, quinidine, procainamide) or class III (eg, amiodarone, sotalol) antiarrhythmic agents. Disturbances of blood glucose w/ antidiabetic agents. Increased AUC of immunosuppressive agents eg, ciclosporin & tacrolimus. Increased risk of tendon rupture w/ corticosteroids particularly in the elderly. Prolonged QT interval w/ fluconazole. Increase risk of CNS stimulation & convulsive seizures w/ NSAIDs. Prolonged elimination t
1/2, elevated theophylline levels, & subsequent increase in risk of theophylline-related adverse reactions. Enhanced effects of warfarin.