Sinuzerc Drug Interactions

Although increased plasma concentrations (AUC 0-24 hours) of loratadine and descarboethoxyloratadine have been reported when the drug was concomitantly administered with therapeutic dosages of ketoconazole, erythromycin, clarithromycin, or cimetidine in controlled clinical pharmacology studies in healthy individuals, no clinically important changes in ECG or laboratory evaluations, vital signs, or adverse effects were reported. Unlike unchanged terfenadine (no longer commercially available in the US), unchanged loratadine does not appear to be cardiotoxic. No specific drug interaction studies have been conducted with fixed-combination extended-release tablets containing loratadine and pseudoephedrine sulfate. Because monoamine oxidase (MAO) inhibitors potentiate the pressor effects of sympathomimetic drugs (e.g., pseudoephedrine), fixed-combination extended-release tablets containing loratadine and pseudoephedrine are contraindicated in patients receiving an MAO inhibitor, or for 2 weeks after discontinuance of an MAO inhibitor. Loratadine does not affect plasma protein binding of warfarin or digoxin. No apparent increase in adverse effects occurred in individuals receiving oral contraceptives concomitantly with loratadine.