<p>Increased risk of hypoglycaemia with concomitant sulfonylureas, dose reduction may be necessary. Increased serum levels with CYP3A4/5 inhibitors (e.g. atazanavir, ketoconazole, nefazodone, ritonavir). Concomitant CYP3A4 inducers (e.g. carbamazepine, phenobarbital) may reduce the glycaemic lowering effect of saxagliptin.</p>