<p>Oxcarbazepine and its metabolite inhibit the enzyme CYP2C19 and therefore, interactions could arise when co-administering high doses of Oxazep with medicinal products that are metabolised by CYP2C19 (e.g. phenobarbital, phenytoin). Concurrent use of Oxazep with hormonal contraceptives may render few contraceptives ineffective (e.g. Ethinylestradiol and Levonorgestrel preparations). Co-administration of Oxazep lowers AUC of felodipine and Verapamil decreases bioavailability of MHD.</p>