Abstract
We retrospectively investigated the dose regulation of sulfonylurea (SU) agents in 219 patients who received dipeptidyl peptidase-4 (DPP-4) inhibitors in addition to SU-based treatment. Of 169 patients who received sitagliptin in addition to SU-based treatment without reducing the dose of the SU agent, 46 (27 %) patients required a reduction of the SU agent within three months for hypoglycemia or to prevent hypoglycemia. Moreover, hypoglycemia occurred in nine (20 %) patients who had been treated with an SU agent at a dose lower than the recommended dose when a DPP-4 inhibitor was added without reducing the dose of the SU agent. However, in 50 patients, when the SU agent was reduced to approximately half the dose, no hypoglycemia was observed, regardless of the previous dose, although the HbA1c-lowering effect was not significantly different from that observed in the patients treated without dose reduction (-0.9 %vs-0.9 %, p=0.95). Therefore, we consider that the dose of SU agents should be halved when a DPP-4 inhibitor is added, regardless of the previous dose of the SU agent.
